AC power interruption and / or drop detection device

Abstract

To solve a problem in which, for the detection of momentary interruption and / or momentary low, it is important to detect the voltage 0 V (zero cross point) and to obtain a time for half the wavelength of an AC power supply voltage signal, and in the past, zero cross detection has been performed by a single photocoupler from a signal that has been full-wave rectified by a rectifier circuit, but it is difficult to obtain the zero-cross point and half-wavelength time with high accuracy due to deviation from the ideal waveform.SOLUTION: By using two photocouplers without full-wave rectification, a zero cross point can be detected with the minimum effect of waveform deviation during rectification and a difference in an operating threshold of the photocoupler, such that the time with a voltage of 0 V can be obtained with high accuracy. It is possible to detect momentary interruptions with high accuracy. Since the zero cross point can be detected with high accuracy, the time required for half a wavelength to detect the instantaneous drop can be detected with high accuracy.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a device for detecting momentary interruptions and / or momentary drops in AC voltage. [Background technology]

[0002] A momentary power outage is when the supply of commercial power is temporarily stopped (for one minute from a half cycle) and the AC voltage or neutral point reference voltage is 0V. A momentary sag, on the other hand, is when the supply of commercial power is not completely stopped, but the AC voltage drops temporarily (for one minute from a half cycle). Tokyo Electric Power Company's general commercial AC 100V is 50Hz, so a half cycle is 10ms. When a momentary power outage occurs, it can cause production equipment to stop, medical equipment in hospitals to stop, and in unprotected devices such as PC hard disks, the head may not be able to retract in time, resulting in destruction. In the case of a momentary power drop, UPS devices may malfunction, and magnetic switch motors may stop. For this reason, it is necessary to detect the occurrence of momentary power outages and momentary power drops, and to take appropriate action on the necessary equipment. After detection, actions such as backing up data, transitioning to a state where turning off the power will not have any impact, and switching to an emergency power source can be taken promptly. In the case of a momentary power outage, a state of 0V voltage continues, so it is important to detect the moment when the voltage is 0V and the duration of that state. In addition, in the case of a momentary power drop, voltage fluctuations are detected by calculating voltage value information every half cycle and comparing it to see if it has dropped below the normal value.

[0003] Conventional zero-cross detection involves full-wave rectifying an AC voltage and using a photocoupler that uses the full-wave rectified output voltage as an input signal. The period during which the phototransistor that makes up the photocoupler is off (no conduction between the collector and emitter) is measured, and the zero-cross point is detected based on that period.

[0004] The technology disclosed in Document 1 will be explained using FIG. 18. FIG. 18 shows a heater control device (1801) that controls turning on a heater (1811) at a zero-cross point to prevent flicker (flickering in fluorescent lights, cathode ray tubes, etc.), and includes a zero-cross detection device (1802) that detects the zero-cross point. This heater control device has a circuit configuration as shown in FIG. 18(a). The zero-cross detection device (1802) includes a rectifier circuit (1804) that full-wave rectifies the AC voltage supplied from a power supply (1803), and a photocoupler (1805) that receives the output voltage of the rectifier circuit (1804) as an input signal. The photocoupler (1805) is composed of a photodiode D1 and a phototransistor Tr1. The anode of the photodiode D1 is connected to the output of the rectifier circuit (1804) via a resistor R1, and the cathode of the photodiode D1 is connected to ground.

[0005] The collector of the phototransistor Tr1 is connected to the DC power supply VDD via a resistor R2 and to the base of the transistor Tr2, and the emitter of the phototransistor Tr1 is connected to ground. The collector of the transistor Tr2 is connected to the DC power supply VDD via a resistor R3, and the emitter of the transistor Tr2 is connected to ground. The control unit (1806) also has a zero-cross time measurement means (1807), a delay time calculation means (1809), and a delay means (1810), and is connected to the collector of the transistor Tr2 and the switch unit (1808).

[0006] Also, (b) of Fig. 18 shows the voltage waveform of the AC power supply (1803), (c) of Fig. 18 shows the input signal waveform of the photocoupler (1805) (output voltage waveform of the rectifier circuit (1804)), (d) of Fig. 18 shows the waveform of the collector output of transistor Tr2, and (e) of Fig. 18 shows the waveform of the heater control signal.

[0007] The AC voltage (FIG. 18(b)) from the AC power supply (1803) is full-wave rectified by the rectifier circuit (1804), and the full-wave rectified voltage (FIG. 18(c)) is applied to the light-emitting diode D1 of the photocoupler (1805) via the resistor R1. As a result, a forward current proportional to the voltage of the AC power supply (1803) flows through the light-emitting diode D1, and this forward current causes the light-emitting diode D1 to emit light.

[0008] Furthermore, when phototransistor Tr1 of the photocoupler (1805) receives light emitted from this light-emitting diode D1, a base current flows and conduction occurs between its collector and emitter. Therefore, the collector voltage of phototransistor Tr1 becomes the ground voltage, so that no base current flows through transistor Tr2, transistor Tr2 turns off, and the collector voltage of transistor Tr2 becomes "H" (the voltage of the DC power supply VDD).

[0009] Furthermore, when the amplitude of the voltage of the AC power supply (1803) decreases, the forward current flowing through the photodiode D1 decreases, and the amount of light emitted by the photodiode D1 decreases. When the amount of light emitted by the photodiode decreases, no base current flows through the phototransistor Tr1, and the phototransistor Tr1 turns off. Then, a base current flows from the DC power supply VDD to the base of the transistor Tr2 via resistor R2, turning the transistor Tr2 on and causing the voltage at the collector of the transistor Tr2 to go to "L" (ground voltage).

[0010] In other words, if the voltage of the AC power supply (1803) when the transistor Tr2 turns on is Vth, then when the absolute value of the voltage of the AC power supply (1803) is smaller than Vth, the transistor Tr2 turns on and the voltage of the collector of the transistor Tr2 becomes "L" (ground voltage), as shown in (c) and (d) of Figure 18. Furthermore, the period when the transistor Tr2 is on, that is, the period when the voltage of the collector of the transistor Tr2 is "L", is the period near the zero cross of the voltage waveform of the AC power supply (1803), so this period is called the zero cross period, and the signal indicating this zero cross period, shown in (d) of Figure 18, is called the zero cross signal.

[0011] This zero-cross signal is then input to the control unit (1806), which then uses a delay means (1810) to delay a heater control signal (FIG. 18(e)) that has been delayed from the falling edge of this zero-cross signal by the delay time calculated by the delay time calculation means (1809) and outputs the delayed signal to the switch unit (1808). The switch unit (1808) is then triggered by the heater control signal and is turned on, so that AC power from the AC power supply (1803) is supplied to the heater (1811).

[0012] A heater control signal (FIG. 18(e)) delayed by the delay time calculated by the delay time calculation means (1809) from the falling edge of this zero-cross signal is output to the switch section (1808). The switch section (1808) is then turned on using the heater control signal as a trigger, and AC power from the AC power supply (1803) is supplied to the heater (1811).

[0013] Here, the control unit (1806) starts its delay time calculation operation when power is applied to the heater control device (1801), i.e., when power is applied to the control unit (1806). Next, it determines whether a zero-cross signal has been detected. This is done by determining whether the collector output of transistor Tr2 has become "L," i.e., whether the falling edge of the zero-cross signal has been detected. Then, when the falling edge of the zero-cross signal is detected, it begins measuring the width of the zero-cross signal. That is, the zero-cross time measurement means (1807) measures the time from the falling edge to the rising edge of the zero-cross signal. This time from the falling edge to the rising edge of the zero-cross signal is the length of the zero-cross period, and is therefore called the zero-cross time. Then, after measuring the zero-cross time, the delay time is calculated by the delay time calculation means (1809). On the other hand, if the zero-cross time cannot be measured, it starts detecting the zero-cross signal again.

[0014] The delay time is calculated by the delay time calculation means (1809) by multiplying the measured zero cross time by 1 / 2. For example, in the case of the AC voltage waveform shown in FIG. 18(b), the zero cross time measured by the zero cross time measurement means (1807) is multiplied by t a Then, the control unit (1806) calculates the zero cross time t a The delay time t is 1 / 2 of the time a Then, the control unit (1806) calculates the delay time t / 2 from the start point of the zero cross period, that is, the falling edge of the zero cross signal, by the delay means (1810). a The heater control signal ((e) in FIG. 18) is delayed by 1 / 2 and output to the switch section (1808). As described above, the zero crossing point is detected, and heater control is performed based on it. [Prior art documents] [Patent documents]

[0015] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-123977 Summary of the Invention [Problem to be solved by the invention]

[0016] At first glance, the zero-cross detection device in the heater control device of Patent Document 1 appears to accurately detect the zero-cross point. However, the voltage that actually passes through the rectifier circuit is not output with the ideal waveform as shown in Figure 18(c) due to factors such as the operating threshold voltage of the diode used for rectification (generally about 0.6V, which varies slightly depending on the product). When the operating threshold voltage of the diode is 0.6V, the rectifier diode does not turn on when the input voltage waveform is in the range of +0.6V to -0.6V, and flat portions of 0V are generated between the peaks of the input voltage waveform of the photocoupler shown in Figure 18(c) (the waveform folded back by full-wave rectification). This is why the t shown in Figure 18(d) a However, the difference is widened and is affected by the threshold voltage of the rectifier diode as well as the operating threshold voltage of the photocoupler, making it difficult to detect the zero-crossing point with high accuracy. [Means for solving the problem]

[0017] A momentary interruption can be detected by accurately detecting the zero crossing point and determining whether the time the voltage is 0V exceeds a predetermined time. By accurately detecting the zero crossing point, the period of the AC power supply voltage can be accurately determined, and the presence or absence of a momentary drop can be determined from the integral value of the voltage signal over that period. Therefore, in order to solve the above problems, a first invention provides a power supply circuit including: an AC power supply signal acquisition unit that acquires an AC power supply signal; a first photocoupler that outputs a light-receiving signal when the acquired AC power supply signal is positive, and does not output a light-receiving signal when the acquired AC power supply signal is negative; a second photocoupler that does not output a light-receiving signal when the acquired AC power supply signal is positive, and that outputs a light-receiving signal when the acquired AC power supply signal is negative; a counter for counting a signal width, which is an arbitrary time interval of the AC power signal; a comparative time length information storage unit that stores comparative time length information, which is information indicating a predetermined time length to be compared with non-light-receiving time length information, which is information indicating a value counted by the counter during a period when no light-receiving signal is acquired from either the first photocoupler or the second photocoupler; a comparison unit that compares the non-light-receiving time length information with the comparison time length information; a comparison result output unit that outputs a comparison result when the comparison result is a predetermined comparison result; The present invention provides a power interruption detection device having the following configuration.

[0018] Furthermore, as a second invention, based on the first invention, there is provided an instantaneous power interruption detection device in which the comparative time length information holding section holds information indicating a plurality of comparative time length information as the comparative time length information.

[0019] Furthermore, as a third invention, based on either the first or second invention, the first photocoupler is configured to output a signal L when the acquired AC power supply signal is positive, and to output a signal H when the acquired AC power supply signal is negative, the second photocoupler is configured to output a signal H in response to a positive AC power signal, and to output a signal L in response to a negative AC power signal; "The time difference between the first timing at which the signal of the second photocoupler switches from L to H and the second timing at which the signal of the first photocoupler switches from H to L in the same timing region where the AC power supply signal inverts from negative to positive" or / and, a time difference acquisition unit that acquires "a time difference between a third timing at which the signal of the second photocoupler switches from H to L and a fourth timing at which the signal of the first photocoupler switches from L to H in the same timing region where the AC power supply signal is inverted positive and negative"; a voltage zero timing acquisition unit that acquires a timing of voltage zero of the AC power signal using a corrected time length that is half the time length of the acquired time difference; The present invention provides a power interruption detection device further comprising an AC voltage zero-cross detection circuit structure comprising:

[0020] Furthermore, as a fourth invention, based on the third invention, there is provided a power interruption detection device in which the first photocoupler and the second photocoupler have approximately equal ON delay time lengths.

[0021] Furthermore, as a fifth invention, based on either the third or fourth invention, there is provided a power interruption detection device further having a corrected time length acquisition unit that statistically processes multiple acquired time differences to acquire a corrected time length.

[0022] Furthermore, as a sixth invention, based on any one of the third to fifth inventions, there is provided a power interruption detection device in which the first photocoupler and the second photocoupler output L when the photocoupler is ON.

[0023] Furthermore, as a seventh invention, based on any one of the third to sixth inventions, there is provided an instantaneous power interruption detection device having preemptive means, wherein the zero-cross timing acquisition unit acquires the zero-cross timing using the timing at which the signal of the first photocoupler rises from L to H just before the zero-cross timing and a correction time length when the AC power supply signal inverts from positive to negative, and acquires the zero-cross timing using the timing at which the signal of the second photocoupler rises from L to H just before the zero-cross timing and a correction time length when the AC power supply signal inverts from negative to positive.

[0024] Furthermore, the present invention provides respective operation methods and respective operation programs corresponding to the instantaneous power interruption detection devices of the first to seventh aspects of the present invention. The respective operation programs may be recorded on a recording medium.

[0025] Furthermore, as an eighth invention, an AC power supply signal acquisition unit that acquires an AC power supply signal; a power supply step-down unit having an isolation transformer for stepping down an AC power supply voltage; an AC full-wave rectification unit that full-wave rectifies the AC voltage stepped down by the power supply voltage step-down unit; An AD conversion unit that converts the full-wave rectified waveform into AD; An integrating section that integrates the AD converted half wavelength. a predetermined comparison value holding unit that holds a predetermined comparison value, which is a predetermined value for determining whether the integral value of each half wavelength obtained is normal; an abnormality / normality determination unit that compares the obtained integral value for each half wavelength with a stored predetermined comparison value and determines whether the state is an abnormal voltage sag state or a normal state; A power voltage sag detection device having a judgment result output unit that outputs the judgment result, The present invention provides a power dip detection device, characterized in that the AC power signal acquisition unit is shared with the power interruption detection device of any one of the first to seventh inventions.

[0026] Furthermore, as a ninth invention, based on the eighth invention, a counter included in the instantaneous power interruption detection device of any one of the first to seventh inventions is A power voltage drop detection device is provided in which at least one of an AD conversion unit, an integration unit, a comparison predetermined value holding unit, an abnormality / normality determination unit, and a determination result output unit is functionally integrated into the same microcomputer.

[0027] Furthermore, as a tenth aspect of the present invention, based on the eighth aspect of the present invention, there is provided a power sag detection device that uses the zero-cross points obtained by the AC voltage zero-cross detection circuit structure of any one of the third to seventh aspects of the present invention when integrating over a half wavelength.

[0028] Furthermore, there are provided respective operation methods and respective operation programs corresponding to the power voltage dip detection devices of the eighth to tenth aspects of the present invention. The respective operation programs may be recorded on a recording medium. [Effects of the Invention]

[0029] According to the present invention, it is possible to detect the period when an instantaneous interruption occurs with high accuracy. It is possible to detect a voltage sag with high accuracy. By using an AC voltage zero crossing point detection circuit structure, it is possible to detect the period when an instantaneous interruption occurs with even higher accuracy, or to detect a voltage sag with even higher accuracy. By sharing components, it is possible to provide an instantaneous interruption and / or voltage sag detection device at low cost. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a functional block diagram according to a first embodiment of the present invention. [Figure 2] 1 is a flowchart according to the first embodiment of the present invention. [Figure 3] FIG. 1 is a schematic diagram of a hardware configuration according to a first embodiment of the present invention. [Figure 4] 5A to 5C are signal waveform diagrams illustrating the effects of the first embodiment of the present invention. [Figure 5] FIG. 10 is a functional block diagram according to a second embodiment of the present invention. [Figure 6] FIG. 10 is a schematic diagram of a hardware configuration according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a functional block diagram according to a third embodiment of the present invention. [Figure 8] 10 is a flowchart according to a third embodiment of the present invention. [Figure 9] FIG. 10 is a schematic diagram of a hardware configuration according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a functional block diagram according to a fourth embodiment of the present invention. [Figure 11] 10 is a flowchart according to a fourth embodiment of the present invention. [Figure 12] FIG. 10 is a schematic diagram of a hardware configuration according to a fourth embodiment of the present invention. [Figure 13] FIG. 10 is a functional block diagram according to a fifth embodiment of the present invention. [Figure 14] 10 is a flowchart according to a fifth embodiment of the present invention. [Figure 15] FIG. 10 is a schematic diagram of a hardware configuration according to a fifth embodiment of the present invention. [Figure 16] FIG. 10 is a signal waveform diagram illustrating calculation of a correction time length according to a fifth embodiment of the present invention. [Figure 17] FIG. 1 is a functional block diagram of a microcomputer according to a first embodiment of the present invention. [Figure 18] Schematic diagram of a conventional circuit configuration and waveform diagrams of each point in the circuit [Figure 19] FIG. 13 is a functional block diagram according to an eighth embodiment of the present invention. [Figure 20]FIG. 13 is a schematic diagram of a hardware configuration according to an eighth embodiment of the present invention. [Figure 21] FIG. 13 is a signal waveform diagram illustrating a voltage sag detection according to an eighth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention should not be limited to these embodiments and can be embodied in various forms without departing from the spirit of the present invention.

[0032] The functional configuration of each embodiment described below can be realized as a combination of hardware and software, as will be described later. Each embodiment described herein can be realized not only as an apparatus, but also as a method of operation, in part or in whole. A portion of such an apparatus can also be configured as software. Furthermore, software products used to cause a computer to execute such software, and recording media on which such products are fixed, are naturally included within the technical scope of each embodiment described herein (the same applies throughout this specification).

[0033] <Embodiment 1> <Embodiment 1 Overview: Mainly Claim 1> Instantaneous power interruption device: Basic The first embodiment will be described. The time during which no light reception signal is obtained from either the first or second photocoupler is compared with a predetermined time length, and if the comparison result is a predetermined result, an output is issued to that effect.

[0034] <Configuration of Embodiment 1> The instantaneous power interruption detection device according to the embodiment of the present invention will be described below in the order of functional configuration, processing flow, and circuit configuration. 1 is a functional block diagram showing an embodiment of the instantaneous power interruption detection device of this embodiment. As shown in the figure, the instantaneous power interruption detection device (0100) is composed of an AC power signal acquisition unit (0101), a first photocoupler (0102), a second photocoupler (0103), a counter (0104), a comparison unit (0105), a comparison time length information storage unit (0106), and a comparison result output unit (0107). The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0035] <Embodiment 1: AC Power Supply Signal Acquisition Unit (0101)> The 'acquiring unit for AC power supply signal' (0101) is configured to acquire an AC power supply signal. The intermediate path between the instantaneous power interruption detection device of the present invention and the power source for which instantaneous interruption is to be detected is designed with care to prevent a voltage phase shift.

[0036] <Embodiment 1: First Photocoupler (0102)> The "first photocoupler" (0102) is configured to output a light-receiving signal when the acquired AC power signal is positive, and not output a light-receiving signal when the acquired AC power signal is negative. A photocoupler is generally an element that integrates a light-emitting diode, which is a light-emitting element, and a phototransistor that is turned on when the light from the light-emitting diode is received, into a single package. By using a photocoupler, it is possible to configure an LED section that operates on an AC power supply signal with a reduced voltage using a configuration that does not affect the AC voltage phase, such as a current-limiting resistor, and a circuit that operates on DC, such as a phototransistor, which is a light-receiving element for detecting zero crossing points, and a microcontroller, while isolating them from the AC power supply, without shifting their phase.

[0037] <Embodiment 1: Second Photocoupler (0103)> The "second photocoupler" (0103) is configured not to output a light receiving signal when the acquired AC power supply signal is positive, and to output a light receiving signal when the acquired AC power supply signal is negative. In this embodiment, in FIG. 1 and FIG. 3 described later, the first photocoupler (0102) and the second photocoupler are shown as an integrated component comprising two photocouplers, but a similar circuit configuration may be achieved using individual components.

[0038] <Embodiment 1 Counter (0104)> The "counter" (0104) is configured to count a signal width, which is an arbitrary time interval of the AC power signal, and is configured to count the length of the non-light receiving time during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler. The counter function can be configured using the timer / counter function built into a commercially available microcontroller.

[0039] <Embodiment 1: Comparative Time Length Information Storage Unit (0106)> The "comparison time length information storage unit" (0106) is configured to store comparison time length information, which is information indicating a predetermined time length to be compared with non-light receiving time length information, which is information indicating the value counted by the counter during the period when no light receiving signal is acquired from either the first or second photocoupler. As the comparative time length information, comparative time length information according to the target device is held. Instead of setting and inputting the information during the manufacturing process, a comparative time length information input unit may be further provided, and the comparative time length information may be determined at the installation site of the device, and the information may be input and held.

[0040] <Embodiment 1: Comparison Unit (0105)> The 'comparison unit' (0105) is configured to compare the non-light receiving time length information with the comparison time length information. If a commercially available microcomputer chip that includes the function of the counter (0104) is used, the function can be easily obtained. An example of this is the PIC16F1 series of microcontroller chips manufactured by Microchip Technology. These chips have the ability to count the pulse width or the time for one high-low cycle of an external input signal. For example, in some models of the PIC16F1 series, when the system frequency is 32 MHz, four cycles are required to execute one instruction, resulting in a timer count frequency of 32 MHz / 4 = 8 MHz. One cycle of a 50 Hz AC power supply voltage signal lasts 20 msec. When measured at 8 MHz, this results in 160,000 counts per cycle, exceeding the upper limit of 65,536 for a counter using a 16-bit memory area. Therefore, by dividing the signal by four using the prescaler function (selectable from 1, 4, or 8 divisions), the count becomes 40,000, making it possible to measure it with a 16-bit counter. Furthermore, in the case of a general commercial AC single-phase 100V power supply (50Hz) in eastern Japan, the time between the photocoupler's ON / OFF threshold voltage of approximately 0.8V and 0V is approximately 25μs if the AC voltage waveform is an ideal sine wave. When measured with the 8MHz counter, this counts to approximately 200, and even when divided by 4, it is approximately 50, which is sufficient for measurement. Hereinafter, in this specification, terms such as "time," "time length," "time difference," and "timing" measured by a counter may not necessarily be in units of time, but may also be in units of counter counts or count number information derived from the count number, and may be interpreted interchangeably.

[0041] <Embodiment 1: Comparison result output unit (0107)> The 'comparison result output unit' (0107) is configured to output a message to that effect when the comparison result is a predetermined comparison result. It is preferable that the output section outputs an H potential under normal conditions, and in the event of an abnormality (when a momentary interruption is detected), it becomes the same L potential or open state potential as when the circuit is off. This is so that if any kind of malfunction occurs in the momentary interruption detection device itself, or if a line between the output of the momentary interruption detection device and the device receiving the output result (such as an emergency power switching device) is broken, it can be treated as an abnormality and the same response as in the event of a momentary interruption. If the configuration is such that an H potential is output when a momentary interruption is detected, in the event of a malfunction such as a line being broken, the momentary interruption detection signal will not reach the device, the power switching device will not operate, and life-threatening equipment such as an artificial heart-lung machine may stop working.

[0042] <Processing flow of embodiment 1> 2 is a flowchart illustrating the operation of the instantaneous power interruption detection device according to the first embodiment. As shown in the figure, the operation method of the instantaneous power interruption detection device according to the embodiment includes a comparison time length information storage step (S0201), a comparison step (S0202), and a comparison result output step (S0203). Each step will be described below.

[0043] an AC power signal acquisition unit that acquires an AC power signal; a first photocoupler that outputs a light-receiving signal when the acquired AC power supply signal is positive, and does not output a light-receiving signal when the acquired AC power supply signal is negative; a second photocoupler that does not output a light receiving signal when the acquired AC power supply signal is positive, and that outputs a light receiving signal when the acquired AC power supply signal is negative; a counter for counting a signal width of the AC power supply signal; In a power interruption detection device comprising: The comparison time length information holding step (S0201) performs a process of holding information indicating comparison time length information to be compared with the non-light receiving time length in the counter when a light receiving signal is not acquired from either the first photocoupler or the second photocoupler, The AC power supply signal acquisition step (S0202) performs a process of acquiring an AC power supply signal, The comparing step (S0203) performs a process of comparing a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S0204) performs processing to output a message indicating that the comparison result is a predetermined comparison result. This is an operating method for causing the power interruption detection device to execute a series of processes.

[0044] <Hardware Configuration of First Embodiment> The hardware configuration of the instantaneous power interruption detection device in this embodiment will be described with reference to the drawings. Fig. 3 is a schematic diagram for explaining the circuit configuration of the instantaneous power interruption detection device (0300) of embodiment 1. It is composed of an AC power supply (0301), a current limiting resistor (0302), a two-circuit photocoupler (0303), a microcomputer (0304), a counter (0305), a zero-cross measurement calculation (0306), a comparison judgment (0307), a comparison time length information storage (0308), a zero-cross detection output (0309), a comparison result output (0310), etc.

[0045] The microcontroller used is a commercially available one, but in this example, we assume the use of a product with a built-in counter and pulse generation function, such as the PIC16F1 series mentioned above. The microcontroller configuration is explained using Figure 17. The microcontroller (1700) is composed of a control circuit (1701), an arithmetic circuit (1702), a register (1703) consisting of RAM used for temporary storage, a data memory (1704) consisting of RAM for storing data, a clock generator (1705) for executing various microcontroller operations, a program memory (1706) consisting of non-volatile memory for storing various programs, a port control (1707) for controlling various ports, a timer based on pulses from the clock generator (1705) built into the microcontroller or an external crystal oscillator, a counter / timer (1708) with a counter function that starts counting when triggered by an external input, a serial communication (1709) for communicating with the outside, and an AD / DA converter (1710). Programs written in a high-level language such as C or assembler using program development software on a separate PC are written to the microcomputer using a dedicated tool. The written programs are stored in the program memory (1706) within the microcomputer. The program memory (1706) is a rewritable type of memory that retains records even when power is not supplied, such as an EEPROM or flash memory. The programs stored in the program memory (1706) include a program that uses the start or stop timing of acquisition of the light-receiving signal output from the photocoupler as a trigger to input the data into the counter / timer (1708) and operate the counter, a program that compares the length of time during which no light-receiving signal is obtained from both the first and second photocouplers with a predetermined time, and a program that outputs the comparison result if it is the predetermined comparison result.

[0046] The counter / timer (1709) will be described using the comparison time length as an example of comparison time length information (which may be time units, clock counts, or a natural number multiple). The counter / timer (1708) senses the start or stop of acquisition of the light-receiving signal output from the photocoupler and acquires the count as a trigger. It acquires a reference clock or its divided clock signal and counts up the corresponding register. The comparison program checks whether the comparison time length has been reached during the count-up, and if the comparison time length has been reached, outputs this information. If it detects another acquisition or stop of the light-receiving signal before the comparison time length is reached, it acquires the count. Under normal operation, the non-light-receiving time length during which no light-receiving signal can be acquired from both the first and second photocouplers is less than 100 μs. If the comparison time length is set to, for example, 3 ms (24,000 counts when using the 8 MHz counter), the non-light-receiving time length will not reach the comparison time length under normal conditions, and it will not be determined to be an instantaneous interruption. When a momentary interruption occurs, the length of non-light receiving time is compared with a comparison time length (e.g., 3 ms), and if it reaches or exceeds the comparison time length, it is compared with the comparison time length and determined to be a momentary interruption, and detection information indicating a momentary interruption is output. It is within the spirit of the present invention to use components such as a counter and pulse generation function outside the microcontroller. Integrating these functions into a single microcontroller is preferable because it is cheaper, smaller, and more convenient.

[0047] The detection of a momentary interruption will be explained using FIG. 4, which shows waveforms at points a, b, and c in the circuit of FIG. 3, which is one example of the configuration of this embodiment. In the signal waveform at point a at the top, the dotted line shows the waveform under normal conditions. The solid line shows a schematic representation of the waveform when a momentary interruption occurs. The arrow indicating the momentary interruption period t is the period when the voltage becomes 0V due to the momentary interruption. CPUs typically used in PCs and other devices include a RESET circuit, which detects a voltage drop due to a momentary interruption in the DC power supply and takes measures to prepare for such interruptions. However, the RESET circuit's detection of momentary interruptions is slow, and problems often occur. Therefore, a faster method of detecting momentary interruptions is needed. In electronic and electrical devices such as PCs, the entire circuit voltage does not immediately drop to 0V due to power supply discharged from the electrical capacitance of the device's internal circuitry. Instead, the voltage drops over a period of approximately tens to hundreds of milliseconds. A momentary interruption detection is required within approximately half a cycle of the AC signal (10 milliseconds at 50 Hz) to enable measures to prepare for a power outage, such as data backup, before the voltage drops below the level required for CPU operation. Lamps for exposure machines in semiconductor production lines, for example, turn off if a voltage drop of 20% or more continues for 50 to 100 milliseconds. They take a long time to re-light and stabilize. Lamps used in production lines, in particular, must maintain a constant illumination level in order to ensure consistent processing accuracy and ensure the production of quality products. Therefore, a judgment within approximately 10 milliseconds is required. Additionally, in AC power switchers (devices that switch from a power source with a problem to a normal power source) used in hospitals and other places, it is considered best to detect the power interruption more quickly, sending a signal in around 4 ms or less, in order to start up and stabilize the power supply after switching. Therefore, it is also necessary to detect momentary interruptions at intervals of around 3 ms. These two types of time are examples of what can be subject to momentary interruption detection.

[0048] In the circuit configuration of Figure 3, at point b in Figure 4, when the AC power supply voltage signal is positive, the first photocoupler turns ON, outputs a light-receiving signal, and becomes an L potential, and at point c, when the AC power supply voltage signal is positive, the second photocoupler turns OFF, does not output a light-receiving signal, and becomes an H potential. As shown in the signal at point a in Figure 4, if a momentary interruption occurs midway through the first positive peak and is restored midway through the negative peak, the first photocoupler will be in the ON state at the start of the momentary interruption period t, but will turn OFF when the voltage drops below the threshold voltage, causing the output signal to stop being output and change from L potential to H potential. Because the AC power supply potential of the second photocoupler was positive when the momentary interruption occurred, it was originally in the OFF state and did not output a light-receiving signal, and point c was at H potential. Even though the voltage drops to 0V due to the momentary interruption, it does not exceed the threshold voltage, so the OFF state continues and point c remains at H potential. Therefore, during the momentary interruption period, neither the first nor second photocoupler outputs a light-receiving signal, and points b and c are both at H potential. When the momentary interruption period ends near the end of the negative period of the AC power supply voltage signal (signal at point a in Figure 4), the second photocoupler turns ON, a light-receiving signal is output, and point c goes to L potential, but within a short time the AC power supply voltage signal changes from negative to positive, the second photocoupler turns OFF, the light-receiving signal is no longer output, and point c goes to H potential. Immediately after the end of the momentary blackout period in Figure 4, the first photocoupler is OFF because the AC power supply voltage signal is negative, so no light-receiving signal is output and point b remains unchanged at H potential. Note that it is also possible to configure the first and second photocouplers so that the light-receiving signal output when they are ON causes the corresponding points b and c to become H potential instead of L potential. In that case, an extra transistor or the like is required for each photocoupler, as in the prior art shown in Figure 18.

[0049] Under normal conditions, both the first and second photocouplers are at a high potential for approximately 50 to 100 microseconds, such as the difference between the first and second timings, or the difference between the third and fourth timings. Therefore, the microcontroller measures the period during which the output signals from the two photocouplers are at a high potential, and uses the results as a predetermined time, such as the aforementioned 3 or 10 milliseconds, to determine whether a momentary interruption has occurred. If the predetermined time is reached or exceeded, a momentary interruption is determined, and a momentary interruption detection signal is output. The bottom of Figure 4 shows an example of a momentary interruption detection output signal. During the period during which neither photocoupler outputs a light-receiving signal, the output is at the OFF potential (preferably the L potential is set to OFF), which is the voltage when the circuit is off. This allows the same measures to be taken for failures due to causes other than momentary interruptions. Using a commercially available microcontroller, such as the PIC16F1 series mentioned above, allows for a simple configuration due to its built-in counter function.

[0050] With the zero-crossing point detection method using a full-wave rectifier and one photocoupler, there is a concern that the detection of the zero-crossing point, which could mark the start of a momentary interruption, may be off due to an improper waveform after rectification, but by using two photocouplers to detect positive / negative and negative / positive changes based on the unrectified AC power supply voltage waveform, the zero-crossing point can be calculated with high precision. Because the start and end points of the voltage reaching 0V can be obtained, it is also possible to calculate the amount of heat that could not be provided to a heating lamp, etc., and control the system to compensate for this after the momentary interruption is restored.

[0051] <Embodiment 2: Mainly Claim 2> Having multiple pieces of comparative time length information <Outline of Embodiment 2> A description will be given of embodiment 2. This embodiment is characterized in that a comparative duration information storage unit stores a plurality of comparative duration information.

[0052] <Configuration of Embodiment 2> The instantaneous power interruption detection device according to the embodiment of the present invention will be described below in the order of functional configuration, processing flow, and circuit configuration. 5 is a functional block diagram of the second embodiment based on the first embodiment. A comparative duration information storage unit (0506) is configured to store a plurality of pieces of comparative duration information. Since the components other than the comparative duration information storage unit (0506) are the same as those of the first embodiment, a description thereof will be omitted.

[0053] <Embodiment 2: Comparative duration information storage unit (0506)> The 'storage unit for comparative time length information' (0506) is configured to store information indicating a plurality of pieces of comparative time length information as comparative time length information. As described above, the plurality of comparison time length information may include, for example, two types of comparison time length information: 3 ms required for switching to an emergency power source, etc., and 10 ms required for saving data from the CPU of a PC, etc. However, the number of types (types) of comparison time length information to be stored is not limited to two and may be increased depending on the device configuration and purpose. The comparison unit (0505) compares the obtained non-light-receiving time length with a plurality of comparison time length information (e.g., comparison time length information 1, comparison time length information 2, etc.), and outputs a predetermined comparison result (e.g., reaching or exceeding the comparison time length information) if the comparison result is a predetermined comparison result. While FIG. 5 shows a single comparison unit (0505), multiple comparison units, such as comparison unit 1 and comparison unit 2, may be provided according to the number of comparison time length information to be stored. Furthermore, multiple comparison result output units, such as comparison result output unit 1 and comparison result output unit 2, may be provided corresponding to the number of comparison time length information to be stored. Each comparison unit may compare one comparison time length information, or one comparison unit may compare multiple comparison time length information, or a combination thereof may be used.

[0054] <Processing flow of embodiment 2> The processing flow of the second embodiment will be explained based on the first embodiment, using the operation flowchart of the instantaneous power interruption detection device in Fig. 2. The difference is that the comparison time length information holding step holds information on a plurality of pieces of comparison time length information, and the comparison unit performs processing to compare the plurality of pieces of comparison time length information with the non-light-receiving time length.

[0055] an AC power signal acquisition unit that acquires an AC power signal; a first photocoupler that outputs a light-receiving signal when the acquired AC power supply signal is positive, and does not output a light-receiving signal when the acquired AC power supply signal is negative; a second photocoupler that does not output a light receiving signal when the acquired AC power supply signal is positive, and that outputs a light receiving signal when the acquired AC power supply signal is negative; a counter for counting a signal width of the AC power supply signal; In a power interruption detection device comprising: The comparison time length information holding step (S0201) performs a process of holding a plurality of pieces of information indicating comparison time length information to be compared with the non-light receiving time length in the counter when a light receiving signal is not acquired from either the first photocoupler or the second photocoupler, The AC power supply signal acquisition step (S0202) performs a process of acquiring an AC power supply signal, The comparing step (S0203) performs a process of comparing a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the plurality of pieces of comparison time length information to be compared; The comparison result output step (S0204) performs processing to output a message indicating that the comparison result is a predetermined comparison result. This is an operating method for causing the power interruption detection device to execute a series of processes.

[0056] <Hardware Configuration of Second Embodiment> The hardware configuration of the instantaneous power interruption detection device in this embodiment will be described with reference to the drawings. Fig. 6 is a schematic diagram for explaining the circuit configuration of the instantaneous power interruption detection device (0600) in embodiment 2. It is composed of an AC power supply (0601), a current limiting resistor (0602), a two-circuit photocoupler (0603), a microcomputer (0604), a counter (0605), a comparison time length information holder (0606), a comparison decision 1 (0607), a comparison result output 1 (0608), a comparison decision 2 (0609), a comparison result output 2 (0610), etc.

[0057] The difference is that the comparison time length information storage (0606) stores a plurality of pieces of comparison time length information, and that comparison judgment 1 (0607), comparison judgment 2 (0609), comparison result output 1 (0608), and comparison result output 2 (0610) are provided according to the number of pieces of comparison time length information stored. This is the same as the first embodiment except that comparison judgments 1 and 2 and comparison result outputs 1 and 2 function exclusively for the corresponding pieces of comparison time length information. Depending on the commercially available microcomputer used, two or more pieces of comparison time length information may be stored. Alternatively, multiple pieces of comparison time length information may be stored, and a single "comparison judgment" may determine which of the multiple pieces of comparison time length information corresponds to a predetermined comparison result. If the comparison result corresponds to the predetermined comparison result, the result may be output from a single "comparison result output." For example, if the comparison time length information is 3 ms and 10 ms, the acquired non-light-receiving time length may be compared and judged to meet or exceed either of the comparison time length information. For example, if it exceeds 3 ms, a DC -5V output may be output, if it exceeds 10 ms, a DC +5V output may be output, and otherwise a DC 0V output may be output. The output terminal may be divided into two. Alternatively, a single comparison unit may be provided with multiple comparison result outputs, and output from multiple output terminals. The configuration of the comparison unit and comparison result output unit is not limited to that shown in FIG. 6, as long as it is possible to store multiple predetermined time lengths and output corresponding comparison results. The output voltage value upon detection of a momentary interruption is also not limited to the value described above. A DC 0V output may also be output upon detection of a momentary interruption. By storing multiple predetermined times, a single power interruption detection device can determine multiple durations of the interruption.

[0058] <Embodiment 3: Mainly Claim 3> Having a zero-cross detection circuit structure <Outline of Embodiment 3> A third embodiment will be described. Based on the first or second embodiment, the third embodiment is characterized by further including an AC voltage zero-cross detection circuit structure. By including the AC voltage zero-cross detection circuit structure, the zero-cross point (voltage 0V) can be accurately obtained and captured, and the start and end points of the momentary interruption can be obtained more accurately. In other words, the duration of the momentary interruption can be accurately obtained. For heating lamps, for example, the energy that was scheduled to be supplied during the momentary interruption can be calculated separately and compensated for.

[0059] <Configuration of Embodiment 3> The instantaneous power interruption detection device according to the embodiment of the present invention will be described below in the order of functional configuration, processing flow, and circuit configuration. 7 is a functional block diagram showing an embodiment of the instantaneous power interruption detection device of this embodiment. As shown in the figure, the instantaneous power interruption detection device (0700) is composed of an AC voltage zero-cross detection circuit structure (0708) composed of an AC power signal acquisition unit (0701), a first photocoupler (0702), a second photocoupler (0703), a time difference acquisition unit (0709), and a zero-cross timing acquisition unit (0710), a counter (0704), a comparison unit (0705), a comparison time length information storage unit (0706), and a comparison result output unit (0707). The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0060] <Embodiment 3: AC power supply signal acquisition unit (0701)> The 'acquiring unit for AC power supply signal' (0701) is configured to acquire an AC power supply signal.

[0061] <Embodiment 3: First Photocoupler (0702)> The "first photocoupler" (0702) is configured to output a signal L when the acquired AC power signal is positive, and to output a signal H when the acquired AC power signal is negative. A photocoupler is generally an element that integrates a light-emitting diode, which is a light-emitting element, and a phototransistor that is turned on when the light from the light-emitting diode is received, into a single package. By using a photocoupler, it is possible to configure an LED section that operates on an AC power supply signal with a reduced voltage using a configuration that does not affect the AC voltage phase, such as a current-limiting resistor, and a circuit that operates on DC, such as a phototransistor, which is a light-receiving element for detecting zero crossing points, and a microcontroller, while isolating them from the AC power supply, without shifting their phase.

[0062] <Embodiment 3: Second Photocoupler (0703)> The 'second photocoupler' (0703) is configured to output a signal H when the acquired AC power supply signal is positive, and to output a signal L when the acquired AC power supply signal is negative. In this embodiment, in FIG. 10 described later, the first photocoupler (1003a) and the second photocoupler (1003b) are shown as an integrated component in the form of a two-circuit photocoupler (1003), but a similar circuit configuration may also be achieved using individual components.

[0063] <Third embodiment: Time difference acquisition unit (0709)> The "time difference acquisition unit" (0709) is configured to acquire "the time difference between the first timing at which the signal of the second photocoupler switches from L to H and the second timing at which the signal of the first photocoupler switches from H to L in the same timing region where the AC power supply signal reverses between negative and positive," and / or "the time difference between the third timing at which the signal of the second photocoupler switches from H to L and the fourth timing at which the signal of the first photocoupler switches from L to H in the same timing region where the AC power supply signal reverses between positive and negative." As shown in the schematic circuit diagram of Figure 10 described below, this function can be easily obtained by using a commercially available microcomputer chip that includes a counter function (for example, the PIC16F1 series microcomputer chips manufactured by Microchip Technology).

[0064] When the AC power supply signal reverses between positive and negative, the counter in the microcomputer detects the fourth timing, which is the rising edge of the pulse when the signal from the first photocoupler changes from L to H, as a trigger and starts counting. After a delay, the counter in the microcomputer detects the third timing, which is the falling edge of the pulse when the second photocoupler changes from H to L, and stops counting the pulse width. The time difference acquisition unit (0709) obtains the number of counts between the third timing and the fourth timing. Conversely, when the AC power supply signal is inverted from negative to positive, the counter of the microcomputer detects the first timing, which is the rising edge of the pulse at which the signal of the second photocoupler changes from L to H, as a trigger, and starts counting, and stops counting the pulse width when the counter of the microcomputer detects the second timing, which is the falling edge of the pulse at which the signal of the first photocoupler changes from H to L. The time difference acquisition unit (0709) obtains the number of counts between the first timing and the second timing. The time difference acquisition unit (0709) may convert the counter clock frequency and frequency division value when the counter counts and the obtained count number into time and transmit them to the zero cross timing acquisition unit (0710), or may transmit them as count numbers. Transmitting the count numbers as they are can save the processing time for multiplication and memory storage. Hereinafter, in this specification, "time," "time difference," "timing," etc. measured by the counter may not be in units of time, but may be interpreted as units of counter count numbers, and may be interpreted interchangeably.

[0065] <Third embodiment: Zero cross timing acquisition unit (0710)> The "zero-cross timing acquisition unit" (0710) is configured to acquire the timing of zero voltage of the AC power signal using a correction time length that is half the time length of the acquired time difference information. The time difference information, which is the difference in the rise and fall timing of the pulses of the first and second photocouplers acquired by the time difference acquisition unit, is multiplied by 1 / 2 and used to correct the zero-cross point of the next half cycle of the AC power signal. As in the embodiment described below, when the AC power signal is inverted, half of the time difference is added to the fourth timing when the signal of the first photocoupler changes from L to H, to correct and output the zero-cross pulse. Even if the zero-cross point shifts due to factors such as variations in power supply frequency caused by fluctuations in power demand, the correction can be reflected half a cycle ahead. Note that due to the operating threshold voltage of the built-in light-emitting diode and the operating threshold voltage of the light-receiving phototransistor, the photocoupler does not immediately begin outputting a light-receiving signal when a voltage is applied from 0 V. Instead, it begins outputting a light-receiving signal when the voltage reaches approximately 0.8 V, depending on the product. Therefore, the first and second photocouplers have an ON delay time until they begin outputting a light-receiving signal even when the AC voltage starts increasing or decreasing from 0 V. The ON delay times of the first and second photocouplers may differ, especially when the first and second photocouplers are configured as a single unit. The ON delay times of both photocouplers may be measured before use, and a photocoupler ON delay time ratio information storage unit may be provided that stores photocoupler ON delay time ratio information indicating the ratio of the ON delay times of the two photocouplers (e.g., ratios such as m:n or 1:k). The acquired time length may be divided based on the photocoupler ON delay time ratio information to obtain a corrected time length. In the description of the third and subsequent embodiments of this specification, multiplying the acquired time length by 1 / 2 can be interpreted as dividing by a ratio such as m:n.

[0066] The method for outputting the zero-cross pulse depends on the specifications of the microcontroller used. For example, as mentioned above, a counter measures only the time difference between the third and fourth timings or the time difference between the first and second timings, and then holds a correction time length equal to half the counter value. One method uses a signal change in the photocoupler output at the first or fourth timing, approximately half a wavelength ahead of the AC power voltage signal, as a trigger, and changes the zero-cross pulse signal potential when the count value equivalent to the held correction time length has advanced. Another method begins monitoring the reference timer count value after the device is started or at an appropriate time after startup, records the count value at the point where the photocoupler output changes (from the first to the fourth timing), and then halves the difference to obtain the correction time length. Another method uses a signal change in the photocoupler output at the first or fourth timing, approximately half a wavelength ahead of the AC power voltage signal, as a trigger, and changes the zero-cross pulse signal potential when the count value equivalent to the held correction time length has advanced. If the AC power supply signal is positive at the start of detection, a predetermined positive DC voltage (e.g., +3 V) is output, and when a correction time length, which is half the time length of the time difference information acquired by the zero-cross timing acquisition unit, is used for correction after half a cycle, the predetermined DC voltage being output can be changed from positive (H potential) to 0 V (L potential) at the predetermined timing to output zero-cross detection. Another method is to output a short rectangular pulse at the predetermined timing so that the rising edge of the pulse coincides with the zero-cross point, but this specification will explain a method of switching the potential of the zero-cross pulse at the predetermined timing.

[0067] <Embodiment 3 Counter (0704)> The "counter" (0704) is configured to count the signal width of the AC power supply signal, and is configured to count the length of the non-light-receiving time when no light-receiving signal is acquired from either the first or second photocoupler. In a normal state, the first and second photocouplers alternate between ON and OFF across the zero cross point, but the counter (0704) counts the period when both are OFF and no light-receiving signal is acquired.

[0068] <Embodiment 3: Comparison Unit (0705)> The "comparison unit" (0705) is configured to compare the non-light-receiving time length during which no light-receiving signal is acquired from either the first or second photocoupler with the comparison time length information to be compared. As this is the same as in the first or second embodiment, a description thereof will be omitted, but the comparison unit (0705) refers to the comparison time length information to be compared, which is stored in the comparison time length information storage unit (0706), and compares it with the non-light-receiving time length measured by the counter (0704). For example, it determines whether the comparison time length information is reached or exceeded. The comparison result output unit (0707) is the same as in the first or second embodiment, so a description thereof will be omitted.

[0069] <Processing flow of embodiment 3>

[0070] <Processing flow of embodiment 3> 8 is an operational flowchart of the instantaneous power interruption detection device of embodiment 3. As shown in this figure, the operation method of the instantaneous power interruption detection device of embodiment 3 includes a comparison time length information retaining step (S0801), an AC power signal acquiring step (S0802), a fourth timing acquiring step (S0803a), a third timing acquiring step (S0803b), a first timing acquiring step (S0803c), a second timing acquiring step (S0803d), a time difference acquiring step (S0804), a zero-cross timing acquiring step (S0805), a comparison step (S0806), and a comparison result outputting step (S0807). Each step will be described below.

[0071] Here, at the timing when the AC power supply waveform changes from positive to negative, The comparative time length information holding step (S0801) performs a process of holding information indicating comparative time length information to be compared with information indicating a non-light receiving time length counted by the counter when a light receiving signal is not acquired from either the first photocoupler or the second photocoupler, The AC power signal acquisition step (S0802) performs a process of acquiring an AC power signal; The fourth timing acquisition step (S0803a) performs a process of acquiring a fourth timing, which is the timing at which the AC power waveform changes from positive to negative, the timing being the same as a timing described below, and the timing at which the signal rises from L to H, from a first photocoupler that outputs a signal L when the acquired AC power signal is positive and outputs a signal H when the acquired AC power signal is negative; The third timing acquisition step (S0803b) performs processing to acquire a third timing, which is the timing at which the signal falls from H to L when the AC power waveform changes from positive to negative, from a second photocoupler that outputs a signal H when the acquired AC power signal is positive and a signal L when the acquired AC power signal is negative, and which is the same timing as the timing described above; The time difference acquisition step (S0804) performs a process of acquiring time difference information that indicates a time difference between the fourth timing and the third timing, a zero-cross timing acquisition step (S0805) performing a process of acquiring zero-cross timings of the AC power supply using the time difference information and any third timing or any fourth timing subsequent to the third timing and the fourth timing; The comparing step (S0806) compares a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S0807) performs processing to output a message indicating that the comparison result is a predetermined comparison result.

[0072] Here, at the timing when the AC power supply waveform changes from negative to positive, The comparative time length information holding step (S0801) performs a process of holding information indicating comparative time length information to be compared with information indicating a non-light receiving time length counted by the counter when a light receiving signal is not acquired from either the first photocoupler or the second photocoupler, The AC power signal acquisition step (S0802) performs a process of acquiring an AC power signal, In the first timing acquisition step (S0803c), a process is performed to acquire a first timing, which is the timing when the AC power waveform changes from negative to positive, the timing being the same as the timing described below, and the timing when the signal rises from L to H, from a second photocoupler that outputs a signal H when the acquired AC power signal is positive and outputs a signal L when the acquired AC power signal is negative; In the second timing acquisition step (S0803d), a process is performed to acquire a second timing, which is the timing at which the signal falls from H to L when the AC power waveform changes from negative to positive, from a first photocoupler that outputs a signal L when the acquired AC power signal is positive and outputs a signal H when the acquired AC power signal is negative, and which is the same timing as the timing described above; In the time difference acquisition step (S0804), a process is performed to acquire time difference information that indicates a time difference between the first timing and the second timing, In a zero-cross timing acquisition step (S0805), a process of acquiring a zero-cross timing of the AC power supply is performed using the time difference information and an arbitrary first timing or an arbitrary second timing subsequent to the first timing and the second timing, The comparing step (S0806) compares a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S0807) performs processing to output a message indicating that the comparison result is a predetermined comparison result. After the time difference acquisition step (S0804), if the acquired time difference information is within a normal range or is a value that can be clearly considered abnormal, such as a value equivalent to half a wavelength, it can be determined to be abnormal and the calculated time difference information can be not used. In this case, the previously calculated time difference information can be used again, or a previously calculated ideal value can be used as the temporary correction length. This is an operating method for causing the power interruption detection device to execute a series of processes.

[0073] Third Embodiment Hardware Configuration The hardware configuration of the instantaneous power interruption detection device in this embodiment will be described with reference to the drawings. Fig. 9 is a schematic diagram for explaining the circuit configuration of the instantaneous power interruption detection device (0900) of embodiment 3. It is composed of an AC power supply (0901), a current limiting resistor (0902), a two-circuit photocoupler (0903), a microcomputer (0904), a counter (0905), a comparison time length information holder (0906), a comparison decision 1 (0907), a comparison result output 1 (0908), a comparison decision 2 (0909), a comparison result output 2 (0910), a zero-cross measurement calculation (0911), a zero-cross detection output (0912), etc. A signal is obtained from the AC power supply (0901) to detect the zero crossing point, and based on the detected zero crossing point, a momentary interruption in the power supply from the AC power supply (0901) is judged. It is preferable to configure the circuit system so that there is no phase shift between the AC power supply signal for measuring the zero crossing point used for detection and the comparison result outputs 1 and 2. This is because if the comparison result is output later than the specified time information, the momentary interruption detection will not be effective. The two-circuit photocoupler (0903) may be configured using a photocoupler for each circuit.

[0074] The microcontroller used is a commercially available one, but we are assuming specifications for a product with a built-in counter and pulse generation function, such as the PIC16F1 series mentioned above. The microcontroller configuration is explained using Figure 17. The microcontroller (1700) is composed of a control circuit (1701), an arithmetic circuit (1702), a register (1703) consisting of RAM used for temporary storage, a data memory (1704) consisting of RAM for storing data, a clock generator (1705) for executing various microcontroller operations, a program memory (1706) consisting of non-volatile memory for storing various programs, a port control (1707) for controlling various ports, a timer based on pulses from the built-in clock or an external crystal oscillator, and a counter / timer (1708) with a counter function that starts counting when triggered by an external input, a serial communication (1709) for communicating with the outside, and an AD / DA converter (1710). Programs written in high-level languages ​​such as C or assembler using program development software on a separate PC are written to the microcontroller using a dedicated tool. The written programs are stored in the program memory (1706) within the microcontroller. The program memory (1706) uses a type of memory that can be rewritten and retains records even without power supply, such as EEPROM or flash memory. The programs stored in this memory include a program that uses the rising and falling timing of the photocoupler output signal as a trigger to input the signal into the counter / timer (1708) to operate the counter for zero-cross detection, and a program that generates a zero-cross pulse based on the count number, which is the obtained time difference information. The output signal from the photocoupler is input to the counter / timer (1708), which detects the timing of a rising or falling edge and starts counting as a trigger. The number of pulses of the reference clock is counted and the corresponding register is counted up. When another rising or falling edge is detected, the counting stops. The calculation unit multiplies the obtained count by 1 / 2 and stores the result in data memory. The count before multiplying by 1 / 2 is compared with the comparative time length information held in memory (for example, 3 ms or a count equivalent to 3 ms), and if it reaches or exceeds the comparative time length information, it is compared with the comparative time length information and determined to be a momentary interruption, and detection information of a momentary interruption is output. It is within the spirit of the present invention to use components such as a counter and pulse generation function outside the microcontroller. Integrating these functions into a single microcontroller is preferable because it is cheaper, smaller, and more convenient.

[0075] Figure 4 will be used to explain how to determine the zero-crossing point. Figures 4a, b, and c also show the signal waveforms at points a, b, and c in the circuit shown in Figure 9. The horizontal axis represents time, and the vertical axis represents voltage. Point a at the top represents point a in Figure 9, i.e., the sine wave power supply signal voltage waveform at AC power supply (0901). When point a, which represents the voltage signal obtained by branching the AC power supply supplied to the target device for which the power interruption detection device (0900) is attempting to detect a momentary interruption, is positive, current flows through the first photocoupler (0903a) in the dual-circuit photocoupler (0903), causing the light-emitting diode to begin lighting up. Focusing on the upwardly convex portion on the right side of the sine wave waveform at the top of Figure 4, the horizontal lines arranged across the zero-crossing (the intersection of the voltage 0V and the voltage signal) represent the ON / OFF threshold voltages of the first and second photocouplers. When the power supply signal (point a) is positive, the light-emitting diode in the first photocoupler (0903a) lights up, the phototransistor receives light and turns ON, and point b is connected to 0V in the circuit via the phototransistor, resulting in an L potential. Conversely, when the power supply signal (point a) is negative, the light-emitting diode in the first photocoupler (0903a) stops lighting up and the phototransistor turns OFF, so point b is supplied with Vcc potential (H potential), a positive DC potential, via resistor R, resulting in an H potential. When the power supply signal (point a) is negative, the light-emitting diode in the second photocoupler (0903b) lights up and the phototransistor turns ON, causing point c to change from H potential to L potential. Note that it is possible to configure a circuit so that the potentials at points b and c become H potential instead of L potential when both photocouplers are ON, but this would increase the number of components, such as transistors, as shown in Figure 14, which is a technique from Reference 1.

[0076] The first photocoupler (0903a) and second photocoupler (0903b) alternately turn on depending on whether the AC waveform of the power supply is positive or negative, and the potential at points b and c changes in a square wave shape. Figure 4 shows the first to fourth timings, which are the timings at which the first photocoupler output and second photocoupler output switch between H potential and L potential. A counter (0905) measures the time between the rising and falling edges of the two square wave pulses, "first timing - second timing" or "fourth timing - third timing," and calculates the timing difference. Due to the threshold voltage at which the light-emitting diode and the phototransistor turn on, when the power supply signal switches from negative to positive or from positive to negative, they do not turn on / off correctly at a voltage of 0V. Therefore, when comparing the pulse waveforms at points b and c, near the point where the power supply voltage becomes 0V, there is a time difference between the rising and falling edges. The time difference may be in the form of a counter count value. Hereinafter, in this specification, the terms "time," "time difference," "timing," and "time length" measured by a counter may be expressed in units other than time, such as counter counts or information derived from the count unit (e.g., an integer multiple of the count number). When a count unit or information derived from a count number is not divisible when multiplying by 1 / 2, the fraction may be rounded up or down. It is preferable to determine in advance how to handle divisibility when the number is not divisible.

[0077] The obtained time difference is multiplied by 1 / 2 in the zero cross measurement calculation (0911), and the value is used to correct the rise and fall timing of the zero cross pulse half a wavelength ahead, and is output as the zero cross detection output (0912). Applying correction to the zero crossing point half a wavelength away means, for example, that when the power supply signal waveform changes from negative to positive, half the time difference can be found and used to correct the next zero crossing point half a wavelength away where the waveform changes from positive to negative. In addition, the value of half the calculated time difference is stored and held, and if the value just calculated is clearly abnormal (for example, a time difference of half a wavelength), it can be configured to not use it for correction but to use a value previously set as a provisional correction time length or the previous value, thereby performing processing without using the half value of the time difference that showed the abnormal value. It is equipped with an AC power supply voltage zero-cross detection circuit structure, and can output the zero-cross detection output (0912) to an external switch unit or the like. The ON / OFF timing of the switch unit, which is made up of switching elements such as thyristors and optical MOS-FET relays, can be controlled using a zero-cross pulse signal. By turning the switch unit ON / OFF at the zero-cross point (the rising or falling edge of the zero-cross pulse), it is possible to suppress noise generation and inrush current generation in the output, and also to make the starting point of control more accurate when adjusting the output using phase control.

[0078] The zero cross point can be calculated more accurately, and in addition to detecting an instantaneous interruption, a zero cross detection output can be output.

[0079] <Embodiment 4: Mainly Claim 4> The characteristics of the two photocouplers are approximately equal <Outline of Embodiment 4> The fourth embodiment will be described. Based on the third embodiment, the first photocoupler and the second photocoupler are configured so that the ON delay time lengths are approximately equal.

[0080] <Configuration of Embodiment 4> The functional configuration, processing flow, and circuit configuration of an instantaneous power interruption detection device according to an embodiment of the present invention will be described below based on embodiment 3. Since the components other than the first and second photocouplers are the same as those in the other embodiments, only the first and second photocouplers will be described. Due to the threshold voltage required for the light-emitting diode that constitutes the photocoupler to emit light and the threshold voltage required for the photodiode, which is the light-receiving element, to turn on, there is a delay time from the zero-crossing point until the photocoupler turns on and outputs a light-receiving signal due to the time difference between when it reaches the operating threshold voltage from 0V. Conversely, when the voltage gradually drops from a voltage exceeding the operating threshold toward 0V, the photocoupler turns off when it reaches the threshold voltage just before 0V (the zero-crossing point), so the photocoupler switches from ON to OFF ahead of the zero-crossing point. A feature of the fourth embodiment is that these ON delay times are approximately equal between the two photocouplers. The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0081] The functional configuration of this embodiment will be described with reference to FIG. <Embodiment 4: First photocoupler (0702) and second photocoupler (0703)> The "first photocoupler" (0702) and the "second photocoupler" (0703) are configured so that the ON delay time lengths are approximately equal. In this embodiment, the first and second photocouplers in Figure 7 are two-circuit photocouplers sealed in a single package. For example, a photocoupler such as the TLP2105 manufactured by Toshiba Electronic Devices & Storage Corporation can be used. Although a similar circuit configuration can be achieved using individual components rather than an integrated package with two circuits, it is empirically easier to obtain photocouplers with approximately equal ON delay times when components from the same manufacturing lot by the same manufacturer are used. If the ON delay times of the first photocoupler (0702) and the second photocoupler (0703) are approximately equal, the accuracy of the calculated value can be expected to be improved when the "time difference between the first timing and the second timing" or the "time difference between the third timing and the fourth timing" is calculated using a counter and the time difference information is multiplied by 1 / 2 to calculate the zero-crossing point. The time difference information is the sum of the ON delay time length and / or ON advance time length of the first photocoupler and the second photocoupler. This is because, when the AC power supply voltage is symmetrical around the zero-crossing point, the time from the threshold voltage at which the photocoupler operates to the voltage of 0V (zero-crossing) and the time from the voltage of 0V to the voltage at which the photocoupler operates are approximately the same. Therefore, when using individual photocouplers, it is preferable to set criteria and select photocouplers with approximately equal ON delay time lengths before use. In the case of a dual-circuit photocoupler, the light-emitting diode and phototransistor are manufactured by the same manufacturer and are expected to have similar characteristics. Also, there is no concern about increased variation between photocouplers due to factors such as thermal history during mounting, mounted resistors, and wiring loads on the board, as occurs when each photocoupler is soldered onto a board separately.

[0082] The processing flow and hardware configuration of the fourth embodiment are the same as those of the third embodiment, and therefore a description thereof will be omitted.

[0083] By making the ON delay time lengths of the first photocoupler and the second photocoupler approximately equal, the proportions that the first photocoupler and the second photocoupler account for in the time difference between the timing at which the signals of the first photocoupler and the second photocoupler switch between L and H near the timing at which the AC power supply voltage switches between positive and negative can be made equal, and the zero crossing point can be calculated with high precision.

[0084] <Embodiment 5: Mainly Claim 5> Correction time length acquisition unit <Outline of Embodiment 5> The fifth embodiment will be described. Based on the third or fourth embodiment, a corrected time length acquisition unit is provided to statistically process a plurality of acquired time differences to acquire a corrected time length.

[0085] <Configuration of Embodiment 5> The following describes the functional configuration, processing flow, and circuit configuration of the instantaneous power interruption detection device according to the fifth embodiment of the present invention, based on the third embodiment. Note that the same effects can be obtained based on the fourth embodiment. 10 is a functional block diagram showing an embodiment of the instantaneous power interruption detection device of this embodiment. As shown in the figure, the instantaneous power interruption detection device (1000) is composed of an AC voltage zero-cross detection circuit structure (1008) consisting of an AC power signal acquisition unit (1001), a first photocoupler (1002), a second photocoupler (1003), a time difference acquisition unit (1009), a correction time length acquisition unit (1011), and a zero-cross timing acquisition unit (1010), as well as a counter (1004), a comparison unit (1005), a comparison time length information storage unit (1006), and a comparison result output unit (1007). Since the components other than the correction time length acquisition unit (1011) are the same as those of the third embodiment, their description will be omitted. The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0086] <Fifth embodiment: Corrected time length acquisition unit (1011)> The 'corrected time length acquisition unit' (1010) is configured to statistically process a plurality of acquired time differences to acquire a corrected time length. The zero-crossing point or the timing at which an AC power signal has a voltage of 0V varies from an ideal sinusoidal waveform due to disturbances such as noise. To obtain a more accurate zero-crossing point, the most recent variation is identified and corrections are made to the zero-crossing point based on that variation. To make corrections, for example, the correction time length is calculated when the power signal waveform changes from negative to positive, and then this can be used to calculate the zero-crossing point half a wavelength after the next change from positive to negative. In this case, the correction time length calculated by multiplying the "time difference between the first timing and the second timing" or the "time difference between the third timing and the fourth timing" by half can be stored and averaged to determine the correction time length. Alternatively, a predetermined number of past data can be set, and only the past data can be averaged and discarded. Until the predetermined number of data is accumulated, the correction time length can be determined by averaging the correction time length based on the correction time lengths accumulated so far. Alternatively, the correction time length calculated each time can be used without averaging until the predetermined number of data is accumulated. Even when used to correct the zero-crossing point half a wavelength later, the variation of the previous predetermined number of data can be calculated. If the variation deviates from the expected maximum or minimum value (e.g., equivalent to 6σ), it can be determined that noise or other disturbances have occurred. The previous value can be excluded and used as the provisional correction time length. Alternatively, a preset ideal value can be used as the provisional correction time length. Zero-crossing detection can be omitted altogether. Other statistical methods, such as a t-test, can be used to determine the presence or absence of disturbances. When calculating the correction time length using past correction time lengths as well, the correction time length cannot be obtained until a predetermined number of times has been accumulated immediately after the start, but in that case, methods such as using one correction time length or not performing correction until a predetermined number of times has passed can be selected and set as appropriate. When calculating the correction time length using past correction time lengths as well, or when validity verification is performed, the extent to which past correction time lengths are used can be determined by, for example, reducing the number of correction time lengths when the variation in correction time lengths is small and increasing the number of correction time lengths when the variation is large, or dynamically reducing the number of correction time lengths when the load of other tasks that the microcomputer used for calculation must process increases, and dynamically restoring it to the original number when the load decreases.

[0087] The instantaneous power interruption detection device (1000) of this embodiment continues to detect zero-crossing points under normal conditions. The method for detecting zero-crossing points and acquiring the correction time length will be described using FIG. 4. The waveforms at points a, b, and c in the circuit of FIG. 3 for embodiment 1 and the circuit of FIG. 12 for embodiment 5 are identical, so the description will be made using FIG. 4. The horizontal axis in FIG. 4 represents time, and the vertical axis represents voltage. Point a at the top represents point a in FIG. 12, i.e., the power supply signal waveform, which is a sine wave at the AC power supply (1201). When point a, which represents the voltage signal obtained by the instantaneous power interruption detection device (1200) branching the signal to have the same phase as the AC power supply source, is positive, current flows through the first photocoupler (1203a) in the dual-circuit photocoupler (1203), and the light-emitting diode begins to light up. In the signal waveform diagram at point a in the figure, the two horizontal lines arranged on either side of 0V represent the ON / OFF threshold voltages of the first and second photocouplers. When the power supply signal (point a) is positive, the light-emitting diode in the first photocoupler (1203a) lights up, the phototransistor receives light, turns ON, and outputs a light-receiving signal. Point b is grounded via the phototransistor, reaching an L potential. Conversely, when the power supply signal (point a) is negative, the light-emitting diode in the first photocoupler (1203a) stops lighting, the phototransistor turns OFF, and the light-receiving signal is no longer output. As a result, point b is supplied with a positive DC potential, Vcc potential (H potential), via resistor R, reaching an H potential. When the power supply signal (point a) is negative, the light-emitting diode in the second photocoupler (1203b) lights up, the phototransistor turns ON, and outputs a light-receiving signal. This causes point c to change from an H potential to an L potential. Note that it is possible to configure a circuit so that the potentials at points b and c become H potential instead of L potential when the photocoupler turns ON; however, this would increase the number of components, such as transistors, as shown in Figure 18, which is a technique described in Reference 1.

[0088] The first and second photocouplers alternately turn on depending on whether the AC waveform of the power supply is positive or negative, and the potential at points b and c changes in a square wave shape. Figure 4 shows the first to fourth timings, which are the timings at which the H potential and L potential of the first and second photocoupler outputs change. A counter (1205) measures the "first timing - second timing" or "third timing - fourth timing" between the rising and falling edges of the two square wave pulses, and calculates the timing difference. Due to the threshold voltage at which the light-emitting diode turns on and the threshold voltage at which the phototransistor turns on, when the power supply signal switches from negative to positive or from positive to negative, it does not turn on / off correctly at a voltage of 0 V. Therefore, when comparing the pulse waveforms at points b and c near the zero-cross point where the power supply voltage becomes 0 V, there is a time difference between the rise and fall.

[0089] The obtained time difference is multiplied by 1 / 2 in the zero cross measurement calculation (1206), and the value is used to correct the rising and falling timing of the zero cross pulse half a wavelength ahead. Applying correction to the zero crossing point half a wavelength ahead means, for example, that when the power supply signal waveform changes from negative to positive, half the value of the time difference t can be found and used to correct the next zero crossing point half a wavelength ahead when it changes from positive to negative. Note that when applying correction half a wavelength ahead, it can also be applied to a natural number multiple of a half wavelength ahead, or it can be interpreted as applying correction to a natural number multiple of a half wavelength ahead. Furthermore, half the value of the calculated time difference information is stored and held, and if the just calculated value is clearly abnormal (for example, time difference information for half a wavelength), it is not used for correction, and the previous value is used instead, so that processing can be performed without using half the value of the time difference information that showed the abnormal value. Whether the obtained correction time length is appropriate or not can be determined using a statistical method. Deviations due to the influence of disturbances such as noise can be excluded. When performing statistical processing using multiple correction time lengths and correcting to the next half wavelength ahead or a natural number multiple of half wavelength ahead, the validity of the multiple correction time lengths to be held and the time difference to be acquired and combined for statistical processing may be evaluated by performing statistical processing using values ​​before multiplying by 1 / 2, or the correction time length may be calculated by multiplying by 1 / 2 only immediately before the time required for correction. This is because if all correction time lengths are held after being multiplied by 1 / 2, errors may accumulate due to rounding up or down when the value is not divisible, and the processing load for halving increases. The zero-cross detection output is output outside the power interruption detection device (1200). If the ON / OFF timing of the switch section, which is made up of switching elements such as thyristors and optical MOS-FET relays, is based on the zero-cross pulse signal, it is possible to control devices such as heaters that use the same AC power supply voltage signal. By turning the switch section ON / OFF at the zero-cross point (the rising or falling edge of the zero-cross pulse), it is possible to suppress noise generation and inrush current generation in the output, and also to make the starting point of control more accurate when adjusting the output using phase control.

[0090] <Processing flow of embodiment 5> 11 is an operational flowchart of the instantaneous power interruption detection device of the third embodiment. As shown in this figure, the operation method of the instantaneous power interruption detection device of the embodiment includes a comparison time length information retaining step (S1101), an AC power signal acquiring step (S1102), a fourth timing acquiring step (S1103a), a third timing acquiring step (S1103b), a first timing acquiring step (S1103c), a second timing acquiring step (S1103d), a time difference acquiring step (S1104), a correction time length acquiring step (S1105), a zero-cross timing acquiring step (S1106), a comparison step (S1107), and a comparison result outputting step (S1108). Each step will be described below.

[0091] Here, at the timing when the AC power supply waveform changes from positive to negative, The comparative time length information holding step (S1101) performs a process of holding information indicating comparative time length information to be compared with information indicating a non-light receiving time length counted by the counter when a light receiving signal is not acquired from either the first photocoupler or the second photocoupler, The AC power supply signal acquisition step (S1102) performs a process of acquiring an AC power supply signal; The fourth timing acquisition step (S1103a) performs a process of acquiring a fourth timing, which is the timing at which the AC power waveform changes from positive to negative, the timing being the same as a timing described later, and the timing at which the signal rises from L to H, from a first photocoupler that outputs a signal L when the acquired AC power signal is positive and outputs a signal H when the acquired AC power signal is negative; The third timing acquisition step (S1103b) performs a process of acquiring a third timing, which is the timing at which the signal falls from H to L when the AC power waveform changes from positive to negative, from a second photocoupler that outputs a signal H when the acquired AC power signal is positive and a signal L when the acquired AC power signal is negative, and which is the same timing as the timing described above; The time difference acquisition step (S1104) includes a process of acquiring time difference information that indicates a time difference between the fourth timing and the third timing; The corrected time length acquisition step (S1105) performs statistical processing on the acquired time differences to acquire a corrected time length; a zero-cross timing acquisition step (S1106) performing a process of acquiring zero-cross timings of the AC power supply using the time difference information and any third timing or any fourth timing subsequent to the third timing and the fourth timing; The comparison step (S1107) performs a process of comparing a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S1108) performs processing to output a message indicating that the comparison result is a predetermined comparison result.

[0092] Here, at the timing when the AC power supply waveform changes from negative to positive, The comparative time length information holding step (S1101) performs a process of holding information indicating comparative time length information to be compared with information indicating a non-light receiving time length counted by the counter when a light receiving signal is not acquired from either the first photocoupler or the second photocoupler, The AC power supply signal acquisition step (S1102) performs a process of acquiring an AC power supply signal, In the first timing acquisition step (S1103c), a process is performed to acquire a first timing, which is the timing when the AC power waveform changes from negative to positive, the timing being the same as the timing described below, and the timing when the signal rises from L to H, from a second photocoupler that outputs a signal H when the acquired AC power signal is positive and outputs a signal L when the acquired AC power signal is negative; In the second timing acquisition step (S1103d), a process is performed to acquire a second timing, which is the timing at which the signal falls from H to L when the AC power waveform changes from negative to positive, from a first photocoupler that outputs a signal L when the acquired AC power signal is positive and outputs a signal H when the acquired AC power signal is negative, and which is the same timing as the timing described above; In the time difference acquisition step (S1104), a process is performed to acquire time difference information that indicates the time difference between the first timing and the second timing, The corrected time length acquisition step (S1105) performs statistical processing on the acquired time differences to acquire a corrected time length; In a zero-cross timing acquisition step (S1106), a process of acquiring a zero-cross timing of the AC power supply is performed using the time difference information and an arbitrary first timing or an arbitrary second timing that follows the first timing and the second timing, and The comparison step (S1107) performs a process of comparing a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S1108) performs processing to output a message indicating that the comparison result is a predetermined comparison result. The corrected time length acquisition step (S1105) may include a corrected time length retention substep that retains previously acquired corrected time lengths. Furthermore, it is preferable to include a corrected time length determination step that determines whether the value obtained in the time difference acquisition step and multiplied by 1 / 2 calculated in the corrected time length acquisition step falls within a reasonable range. This determination is made using a statistical method such as a t-test. If the value is reasonable, it is used as the corrected time length. If it is not reasonable, a provisional corrected time length is output in the provisional corrected time length output step. The provisional corrected time length may be determined based on an ideal value, or the previously used corrected time length may be used. However, if a provisional corrected time length is used, that value is not retained. This is because it would result in erroneous data when using statistical methods to determine the next corrected time length. This is an operating method for causing the power interruption detection device to execute a series of processes.

[0093] <Fifth embodiment: Hardware configuration> The hardware configuration of the instantaneous power interruption detection device in this embodiment will be described with reference to the drawings. Fig. 12 is a schematic diagram for explaining the circuit configuration of the instantaneous power interruption detection device (1200) in embodiment 5. The device is composed of an AC power supply (1201), a current limiting resistor (1202), a dual-circuit photocoupler (1203), a microcomputer (1204), a counter (1205), a comparison time length information holder (1206), a comparison decision 1 (1207), a comparison result output 1 (1208), a comparison decision 2 (1209), a comparison result output 2 (1210), a zero-cross measurement calculation (1211), a zero-cross detection output (1212), and a correction time length acquisition (1213) in the zero-cross measurement calculation (1211). A signal is obtained from the AC power supply (1201) to detect the zero crossing point, and a momentary interruption in the power supply from the AC power supply (1201) is determined based on the detected zero crossing point. It is preferable to configure the circuit system so that there is no phase shift between the AC power supply signal for measuring the zero crossing point used for detection and the comparison result outputs 1 and 2. This is because if the comparison result is output later than the specified time information, the momentary interruption detection will not be effective. The two-circuit photocoupler (1203) may be configured using a photocoupler for each circuit. The difference from the example in Fig. 9 is that the correction time length acquisition (1213) is provided within the zero-cross measurement calculation (1211). As described above, the correction time length acquisition (1207) can be used to acquire and store past correction time lengths, and then find the next correction time length from the stored correction time lengths for a predetermined number of times immediately before, or to determine whether the correction time length immediately before half a wavelength is an abnormal value based on the correction time lengths for a predetermined number of times in the past, and if it is within the normal range, use it as the correction time length when calculating the next zero-cross point.

[0094] In contrast to the third embodiment, the fifth embodiment performs statistical processing on a plurality of acquired time differences to acquire a correction time length for calculating the zero-crossing points, thereby enabling the zero-crossing points to be determined with higher accuracy. Based on the acquired zero-crossing points, the zero-crossing detection output used for controlling the switches of other devices can be output as a more accurate value.

[0095] <Embodiment 6: Mainly Claim 6>: Photocoupler ON and output L <Outline of Sixth Embodiment> The sixth embodiment will be described. Based on any one of the third to fifth embodiments, the first and second photocouplers configure an instantaneous power interruption detection device such that the output becomes L when the photocoupler is ON.

[0096] <Configuration of Embodiment 6> Hereinafter, an instantaneous power interruption detection device according to the sixth embodiment of the present invention will be described based on the third embodiment. The same effects can be obtained even if the fourth or fifth embodiment is used as a base. The functional configuration, processing flow, and circuit configuration will be described in this order. The functional configuration is the same as in the third embodiment. An explanation will be given using Fig. 7. As shown in Fig. 7, the instantaneous power interruption detection device (0700) is composed of an AC voltage zero-cross detection circuit structure (0708) which is composed of an AC power signal acquisition unit (0701), a first photocoupler (0702), a second photocoupler (0703), a time difference acquisition unit (0709), and a zero-cross timing acquisition unit (0710), a counter (0704), a comparison unit (0705), a comparison time length information storage unit (0706), and a comparison result output unit (0707). The parts which differ from the third embodiment will be explained below. The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0097] <Embodiment 6: First Photocoupler (0702)> The "first photocoupler" (0702) is configured to output a signal L when the acquired AC power signal is positive and to output a signal H when the acquired AC power signal is negative, and is further configured so that the output signal becomes L when the photocoupler is ON.

[0098] <Embodiment 6: Second Photocoupler (0703)> The "second photocoupler" (0703) is configured to output a signal H when the acquired AC power signal is positive and to output a signal L when the acquired AC power signal is negative, and is further configured so that the output signal becomes L when the photocoupler is ON. It is possible to configure the circuit so that the output becomes H when the photocoupler is ON, but this can be achieved by adding one transistor and one resistor to the photocoupler output (light-receiving element side), as shown in the circuit of prior art document 1 in Figure 14. In the case of the present invention, two photocouplers are used, so two additional transistors and two additional resistors are required, which increases the number of parts and the cost. For this reason, it is preferable to configure the output so that the output becomes L when the photocoupler is ON.

[0099] <Embodiment 6: Time Difference Acquisition Unit (0704)> The "time difference acquisition unit" (0704) is "the time difference between the first timing when the second photocoupler turns OFF and the output signal switches from L to H, and the second timing when the first photocoupler turns ON and the output signal switches from H to L, in the same timing region where the AC power supply signal is inverted from negative to positive," or / and, It is configured to acquire "the time difference between the third timing when the second photocoupler turns ON and the output signal switches from H to L, and the fourth timing when the first photocoupler turns OFF and the output signal switches from L to H, in the same timing region where the AC power supply signal is inverted positive and negative."

[0100] <Processing flow of embodiment 6> The processing flow is also substantially the same as in the third embodiment. The following description will be made with reference to FIG. 8, which is a flowchart illustrating the operation of the instantaneous power interruption detection device of the third embodiment. As shown in this figure, the operating method of the AC voltage zero-cross detection circuit structure of the sixth embodiment includes a comparison time length information retaining step (S0801), an AC power signal acquiring step (S0802), a fourth timing acquiring step (S0803a), a third timing acquiring step (S0803b), a first timing acquiring step (S0803c), a second timing acquiring step (S0803d), a time difference acquiring step (S0804), a zero-cross timing acquiring step (S0805), a comparison step (S0806), and a comparison result outputting step (S0807). Differences between each step and the third embodiment will be described below.

[0101] Here, at the timing when the AC power supply waveform changes from positive to negative, The AC power signal acquisition step (S0801) performs a process of acquiring an AC power signal branched from the AC power supplied to the component to be controlled, In the fourth timing acquisition step (S0802a), a process is performed to acquire a fourth timing, which is the timing when the AC power waveform changes from positive to negative, the timing being the same as the timing described below, and the timing when the first photocoupler turns OFF and the output signal rises from L to H, from a first photocoupler that turns ON and outputs an output signal L when the acquired AC power signal is positive, and turns OFF and outputs an output signal H when the acquired AC power signal is negative; In the third timing acquisition step (S0802b), a process is performed to acquire a third timing, which is the timing when the second photocoupler turns ON and the output signal falls from H to L when the AC power waveform changes from positive to negative, from a second photocoupler that turns OFF and outputs an output signal H when the acquired AC power signal is positive, and turns ON and outputs an output signal L when the acquired AC power signal is negative, and which is the same timing as the timing described above. In the time difference acquisition step (S0803), a process of acquiring time difference information which is information indicating a time difference between the fourth timing and the third timing is performed; In the zero cross timing acquisition step (S0804), a process is performed to acquire the zero cross timing of the AC power source using this time difference information and any third timing or any fourth timing that follows the third timing and fourth timing.

[0102] Here, at the timing when the AC power supply waveform changes from negative to positive, The AC power signal acquisition step (S0801) performs a process of acquiring an AC power signal branched from the AC power supplied to the component to be controlled, In the first timing acquisition step (S0802c), a process is performed to acquire a first timing, which is the timing when the AC power waveform changes from negative to positive and is the timing when the second photocoupler turns OFF and the output signal rises from L to H, from a second photocoupler which turns OFF and outputs an output signal potential H when the acquired AC power signal is positive, and which turns ON and outputs an output signal potential L when the acquired AC power signal is negative, the first timing being the same as the timing described below when the AC power waveform changes from negative to positive, and which is the timing when the second photocoupler turns OFF and the output signal rises from L to H; In the second timing acquisition step (S0802d), a process is performed to acquire a second timing, which is the timing at which the output signal of the first photocoupler falls from H to L when the AC power waveform changes from negative to positive, from a first photocoupler that turns ON to output an output signal potential L when the acquired AC power signal is positive and turns OFF to output an output signal potential H when the acquired AC power signal is negative, and which is the same timing as the timing described above; In the time difference acquisition step (S0803), a process is performed to acquire time difference information which is information indicating a time difference between the first timing and the second timing, In the zero cross timing acquisition step (S0804), a process is performed to acquire the zero cross timing of the AC power supply using this time difference information and any first timing or any second timing that follows the first timing and second timing. After the time difference acquisition step (S0803), if the acquired time difference information is within a normal range or is a value that can be clearly considered abnormal, such as a value equivalent to half a wavelength, it can be configured to determine that the time difference is abnormal and not use the calculated time difference information. In this case, the previously calculated time difference information can be reused, or it can be processed as 0, assuming that there is no time difference. This is an operating method in which the AC voltage zero cross detection circuit structure executes a series of processes.

[0103] <Hardware Configuration of Sixth Embodiment> The hardware configuration of the structure in this embodiment will be described with reference to FIG. 9 showing embodiment 3. The circuit in FIG. 9 is configured so that when the first photocoupler or the second photocoupler is turned ON (i.e., when the light-emitting diode is lit and the phototransistor receives light and turns ON), point b or point c in the diagram changes from H potential to L potential. Note that the circuit can also be configured so that when the photocoupler is turned ON, the potential at point b or point c becomes H potential instead of L potential; however, as shown in FIG. 18, which is the technology of Literature 1, the number of parts such as transistors and resistors increases, so the configuration in FIG. 9 is preferable.

[0104] <Embodiment 7: Mainly Claim 5>: Preemptive means <Outline of Embodiment 7> A seventh embodiment will be described. Based on any one of the third to sixth embodiments, a zero-cross timing acquisition unit is provided with a pre-acquisition means for acquiring the zero-cross timing by using the timing at which the signal of the first photocoupler rises from L to H just before the zero-cross timing and a correction time length when the AC power supply signal inverts from positive to negative, and acquiring the zero-cross timing by using the timing at which the signal of the second photocoupler rises from L to H just before the zero-cross timing and a correction time length when the AC power supply signal inverts from negative to positive.

[0105] <Configuration of Embodiment 7> The functional configuration, processing flow, and circuit configuration of the instantaneous power interruption detection device according to the seventh embodiment of the present invention will be described below based on the fifth embodiment. The same effects can be obtained based on the third, fourth, and sixth embodiments. 13 is a functional block diagram showing an embodiment of the instantaneous power interruption detection device of this embodiment. As shown in the figure, the instantaneous power interruption detection device (1300) is composed of an AC power signal acquisition unit (1301), a first photocoupler (1302), a second photocoupler (1303), a time difference acquisition unit (1309), a correction time length acquisition unit (1311), a zero-cross timing acquisition unit (1310), an AC voltage zero-cross detection circuit structure (1308) composed of a pre-fetching means (1312) provided in the zero-cross timing acquisition unit (1310), a counter (1304), a comparison unit (1305), a comparison time length information storage unit (1306), and a comparison result output unit (1307). Since the components other than the pre-fetching means (1312) are the same as those of the third embodiment, their description will be omitted. The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0106] <Embodiment 7: Preemption Means (1312)> The "pre-obtaining means" (1312) is configured in the zero-cross timing obtaining unit (1310) so as to obtain the zero-cross timing by using the timing when the signal of the first photocoupler rises from L to H when the AC power supply signal reverses from positive to negative, and to obtain the zero-cross timing by using the timing when the signal of the second photocoupler rises from L to H when the AC power supply signal reverses from negative to positive. Fig. 16 shows signal waveforms at various points (see a, b, and c in the circuit diagram of Fig. 15) in the circuit of the power interruption detection device of embodiment 7. The preemption means (1312) will be described with reference to Fig. 16. F0, D0, F1, and D1 on the vertical axis represent the zero crossing points. F is when the AC power signal goes from negative to positive. n (n=0, 1,), and when it goes from positive to negative, it is Dn(n=0, 1,). F n and D n A on both sides of n , B n , C n , E n indicate the points at which the ON / OFF threshold voltages of the first and second photocouplers are reached, respectively, as shown in the figure. For example, near the point F0 where the AC power supply signal changes from negative to positive, the time difference t1 between A0 where the second photocoupler turns OFF and the output changes, and B0 where the first photocoupler turns ON and the output changes, is obtained by the correction time length acquisition unit (1311), and by adding 1 / 2 of this t1 to the timing where the first photocoupler turns OFF and the output changes from L to H at the falling edge of the AC power supply signal from positive to negative in the next half wavelength, the zero cross timing (i.e., the zero cross point) can be obtained earlier than real time. Near point D0, when the AC power supply signal changes from positive to negative, the time difference t2 between C0, when the first photocoupler turns OFF and the output changes, and E0, when the second photocoupler turns ON and the output changes, is obtained by a correction time length acquisition unit (1311). By adding half of the obtained t2 to the timing when the second photocoupler turns OFF and the output changes from L to H at the rising edge of the AC power supply signal from negative to positive in the next half wavelength, it is possible to obtain the zero-cross timing (i.e., the zero-cross point) earlier than the actual zero-cross point. For example, the microcontroller operates by triggering a counter to start counting when the output of the first photocoupler at C0 changes from signal L to signal H, and by triggering a counter to stop counting when the output of the second photocoupler at E0 changes from signal H to signal L. The microcontroller multiplies the obtained count value by 1 / 2 and calculates the average count value as the correction time length using a predetermined number of past correction time lengths (count values) that have been held. The microcontroller then changes the zero-cross pulse signal potential from L to H when the calculated correction time length (count value) has elapsed since the moment when the output of the second photocoupler at A1, half a wavelength ahead, changed from signal L to signal H. If the ON delay time length and / or ON advance time length of the first photocoupler and the second photocoupler are approximately equal, the contribution of both photocouplers to the time difference (e.g., t2) will be equal, and the accuracy of the value obtained by multiplying the time difference, which is used as the correction time length, by 1 / 2 will improve.

[0107] The timing when the output signal of the first or second photocoupler changes from H to L is called T na The timing when the output signal of the second photocoupler or the first photocoupler changes from L to H is T nb n starts from 1 at an arbitrary time and is used to assign numbers to distinguish the timing at which the photocoupler output signal changes. 1a , T 1b , T 2a , T 2b ,,,T (n-1)a , T (n-1)b , T na , T nb , T (n+1)a , T (n+1)b , and so on. The time difference between the timings is t n Then, tn can be expressed as follows: t n =T nb -T na The average time difference between n timings Δt n teeth, (t1+t2+t3+…+t n-2 +t n-1 +tn ) / n = Δt n It becomes as follows. When calculating the correction time length by halving the time difference, Δt n / 2 = Δt n ' The zero - cross point at half - wavelength ahead is obtained by the following formula. Zero (n+1) = T (n+1)a + Δt n ' When obtaining the correction time length based on the time difference between timings at the n - th time point, the average value of n is calculated, but it may also be possible to trace back a predetermined number k times to the past from the n - th time point. 1 ≤ k < n. This is because as n increases, the data - holding memory area for the past correction time length increases and the processing load also increases.

[0108] Next, the verification of the validity of the obtained correction time length Δt n ' will be explained taking the t - test as an example. Let the number of samples used for verification be m. (1 ≤ m < n) The t - value in the t - test is t = (average of m - Δt n ) / (standard deviation / √m) It can be expressed as follows. Calculate the p - value, and if it is 5% or less, which is generally used as the significance level, it is judged to be valid. The number m of correction time lengths used for verification may be dynamically reduced, for example, when the deviation of the correction time length is small or when the load increases including other processes of the microcomputer.

[0109] Hereinafter, the case of performing a t - test using the past 10 correction time lengths will be explained as an example, but it is not limited to 10, and it may be more or less. The zero - cross point F0 at the left - most time point in FIG. 6 is at the start point of the circuit operation, so the correction time length has not been calculated yet. The change points A0 and B0 of the waveforms of the first photocoupler output and the second photocoupler output are due to the ON / OFF thresholds of the respective photocouplers. For a two - circuit photocoupler, it can be expected that the ON / OFF thresholds are substantially equal. A n 、B n 、C n, E n The time (count value) at A n , B n , C n , E n is expressed as T Fn , T Dn is expressed by the following formula: T F0 =(B0-A0) / 2 T F1 =(B1-A1) / 2 … T Fn =(B n -A n ) / 2 n=1,2,3,… T D0 =(E0-C0) / 2 T D1 =(E1-C1) / 2 … T Dn =(E n -C n ) / 2 n=1,2,3,… When estimating each average value, if we refer to the past 10 samples, The estimated upper and lower limits of the variation in the correction time length are calculated as follows: T FnL,H =T Fn ±t(10-1,0.05)×(V F / (10-1)) (1 / 2) T DnL,H =T Dn ±t(10-1,0.05)×(V D / (10-1)) (1 / 2) t(10-1,0.05) is the correction time length Δt n ' represents the test quantity of the t-test at the 5% significance level for the past 10 samples, and V F , V D represents the respective variance values. Therefore, in the above two equations, T FnL is the lower limit estimate when there is variation based on the correction time length calculated at the Fn point, T FnHrepresents the upper limit estimate when there is variation. It is a verification of whether it is within the range that adjusts the deviation from the average value of the past 10 values. Correction time length T Fn and T Dn A n and C n The value added to this is the zero crossing point. F n Corrected time length T obtained at point Fn From the lower and upper estimates of F n E half wavelength ahead of the point n The point is C n It is expected that the point is within the range of the following formula. n Similarly, the point D is half a wavelength ago. n Corrected time length T obtained at point Dn It is expected that the range will be within the formula below, from the lower and upper estimates of C n +2T FnL <E n <C n +2T FnH A n +T Dn-1L n n +2T Dn-1H If it is not within the range of the above formula, F n or D n At this point, it is assumed that a disturbance such as noise has occurred, and the zero cross pulse is not corrected using the value calculated by statistical processing. In the above case, a provisional correction time length is applied, but the procedure is determined in advance, such as using a provisional correction time length determined from an ideal value, or applying the previous correction time length. If correction is not performed using the calculated correction time length, even if the provisional correction time length is applied, the value is not retained. This is because it will not be used when performing statistical processing based on the retained past correction time lengths to calculate the next correction time length and evaluate the validity of the calculated correction time length.

[0110] ​​In the above explanation, the significance level of 5% corresponds to a 5% defect rate (equivalent to 2σ, with 95% being good products). The oversight rate is usually expected to be about twice as high as a 5% defect rate, so it comes out to 10%. Therefore, by looking at 10 runs, it is thought that anything that is significantly out of line can be eliminated. While the previous 10 correction time lengths were referenced, this number is not limited to 10. When performing statistical processing, the more samples you use, the more accurate the variation and the higher the accuracy. However, increasing the number of samples can delay the start of correction when fluctuations occur, increase the amount of data required, increase memory space, and temporarily increase the amount of memory used during calculation, resulting in increased component costs. There are also disadvantages, such as increased CPU computational load and longer calculation times, which represents a trade-off with accuracy. It is also possible to dynamically change the number of past correction time lengths referenced in statistical methods by monitoring the microcontroller's computational load. In this case, it is recommended to set a minimum and maximum range. Furthermore, depending on the frequency of situations where the power supply signal waveform is affected by external factors, such as when the value obtained by multiplying the time difference by 1 / 2 cannot be used, the number of past correction time lengths referenced can be increased or decreased. Generally, a sample size of around 30 is appropriate for statistical processing, but the designer can select the appropriate number.

[0111] <Processing flow of embodiment 7> 14 is a flowchart illustrating the operation of the instantaneous power interruption detection device of embodiment 7. As shown in this figure, the operation method of the instantaneous power interruption detection device of embodiment 7 includes a comparison time length information retaining step (S1401), an AC power signal acquiring step (S1402), a fourth timing acquiring step (S1403a), a third timing acquiring step (S1403b), a first timing acquiring step (S1403c), a second timing acquiring step (S1403d), a time difference acquiring step (S1404), a correction time length acquiring step (S1405), a zero-cross timing acquiring step (S1406), a look-ahead sub-step (S1407) provided within the zero-cross timing acquiring step (S1406), a comparison step (S1408), and a comparison result output step (S1409). Each step will be described below.

[0112] Here, at the timing when the AC power supply waveform changes from positive to negative, The comparative time length information holding step (S1401) performs a process of holding information indicating comparative time length information to be compared with information indicating a non-light receiving time length counted by the counter when no light receiving signal is acquired from either the first photocoupler or the second photocoupler, The AC power supply signal acquisition step (S1402) performs a process of acquiring an AC power supply signal, The fourth timing acquisition step (S1403a) performs a process of acquiring a fourth timing, which is the timing at which the AC power waveform changes from positive to negative, the timing being the same as a timing described later, and the timing at which the signal rises from L to H, from a first photocoupler that outputs a signal L when the acquired AC power signal is positive and outputs a signal H when the acquired AC power signal is negative; The third timing acquisition step (S1403b) performs a process of acquiring a third timing, which is the timing at which the signal falls from H to L when the AC power waveform changes from positive to negative, from a second photocoupler that outputs a signal H when the acquired AC power signal is positive and a signal L when the acquired AC power signal is negative, and which is the same timing as the timing described above; The time difference acquisition step (S1404) performs a process of acquiring time difference information that is information indicating a time difference between the fourth timing and the third timing, The corrected time length acquisition step (S1405) performs a process of statistically processing the acquired time differences to acquire a corrected time length; The zero-cross timing acquisition step (S1406) includes a sub-step (S1407) for acquiring the zero-cross timing when the AC power supply signal is inverted from positive to negative, and the sub-step (S1407) acquires the zero-cross timing by using a fourth timing at which the signal of the first photocoupler rises from L to H immediately before the zero-cross timing and a correction time length. The comparing step (S1408) compares a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S1409) performs processing to output a message indicating that the comparison result is a predetermined comparison result.

[0113] Here, at the timing when the AC power supply waveform changes from negative to positive, The comparative time length information holding step (S1401) performs a process of holding information indicating comparative time length information to be compared with information indicating a non-light receiving time length counted by the counter when no light receiving signal is acquired from either the first photocoupler or the second photocoupler, The AC power supply signal acquisition step (S1402) performs a process of acquiring an AC power supply signal, In the first timing acquisition step (S1403c), a process is performed to acquire a first timing, which is the timing when the AC power waveform changes from negative to positive, the timing being the same as the timing described below, and the timing when the signal rises from L to H, from a second photocoupler that outputs a signal H when the acquired AC power signal is positive and outputs a signal L when the acquired AC power signal is negative; In the second timing acquisition step (S1403d), a process is performed to acquire a second timing, which is the timing at which the signal falls from H to L when the AC power waveform changes from negative to positive, from a first photocoupler that outputs a signal L when the acquired AC power signal is positive and outputs a signal H when the acquired AC power signal is negative, and which is the same timing as the timing described above; In the time difference acquisition step (S1404), a process is performed to acquire time difference information that indicates the time difference between the first timing and the second timing, The corrected time length acquisition step (S1405) performs a process of statistically processing the acquired time differences to acquire a corrected time length; The anticipatory sub-step (S1407) provided in the zero-cross timing acquisition step (S1406) performs a process of acquiring the zero-cross timing when the AC power supply signal inverts from negative to positive, using the first timing at which the signal of the second photocoupler rises from L to H just before the zero-cross timing and a correction time length; The comparing step (S1408) compares a non-light receiving time length during which no light receiving signal is acquired from either the first photocoupler or the second photocoupler with the comparison time length information to be compared; The comparison result output step (S1409) performs processing to output a message indicating that the comparison result is a predetermined comparison result. The corrected time length acquisition step (S1405) may include a corrected time length retention substep for retaining previously acquired corrected time lengths. Furthermore, it is preferable to include a corrected time length determination step for determining whether the value obtained in the time difference acquisition step and multiplied by 1 / 2 calculated in the corrected time length acquisition step falls within a reasonable range. This determination is made using a statistical method such as a t-test. If the value is reasonable, it is used as the corrected time length. If it is not reasonable, a provisional corrected time length is output in the provisional corrected time length output step. The provisional corrected time length may be determined based on an ideal value, or the previously used corrected time length may be used. However, if a provisional corrected time length is used, that value is not retained. This is because it would result in erroneous data when using a statistical method to determine the next corrected time length. This is an operating method for causing the power interruption detection device to execute a series of processes.

[0114] <Hardware Configuration of Seventh Embodiment> The hardware configuration of the instantaneous power interruption detection device of this embodiment will be described with reference to the drawings. Fig. 15 is a schematic diagram for explaining the circuit configuration of the instantaneous power interruption detection device (1500) of embodiment 7. The device is composed of an AC power supply (1501), a current limiting resistor (1502), a two-circuit photocoupler (1503), a microcomputer (1504), a counter (1505), a comparison time length information holder (1506), a comparison decision 1 (1507), a comparison result output 1 (1508), a comparison decision 2 (1509), a comparison result output 2 (1510), a zero-crossing measurement calculation (1511), a zero-crossing detection output (1512), a correction time length acquisition (1513) in the zero-crossing measurement calculation (1511), and a pre-fetching means (1514) in the zero-crossing detection output (1512). A signal is obtained from the AC power supply (1501) to detect the zero crossing point, and a momentary interruption in the power supply from the AC power supply (1501) is determined based on the detected zero crossing point. It is preferable to configure the circuit system so that there is no phase shift between the AC power supply signal for measuring the zero crossing point used for detection and the comparison result outputs 1 and 2. This is because if the comparison result is output later than the specified time information, the momentary interruption detection will not be effective. The two-circuit photocoupler (1503) may be configured using a photocoupler for each circuit.

[0115] In the seventh embodiment, the zero cross point that can be the starting point for detecting an instantaneous interruption period is calculated by applying the obtained correction time length to a point half a wavelength ahead of the AC power supply voltage waveform, so that the zero cross point can be determined before the time when the zero cross point actually occurs (voltage 0V).

[0116] <Another example of preemptive measures> In the first to seventh embodiments, the time between the rise and fall of the first and second photocouplers (t1, t2, and t3 in FIG. 16) is measured using a counter. However, the periods of the output signals of the first and second photocouplers may also be measured. This will be explained using FIG. 16. For example, the number of counts elapsed since startup is monitored, and the number of counts at point B0, when the output of the first photocoupler changes from signal H to signal L, is recorded, and the period of signal L is counted and measured. Next, the number of counts at point C0, when the output changes from signal L to signal H, is recorded, and the period of signal H is counted and measured. Similarly, the number of counts at points B1 and C1 are recorded. Similarly, the number of counts at points A0, E0, A1, E1, etc. are measured and recorded for the output signal of the second photocoupler. The time difference between the rise and fall of the first and second photocouplers is obtained as a count value by t1 = (count value at point B0 - count value at point A0). The correction time length is obtained as t1 / 2. As in the seventh embodiment, the obtained correction time length t1 / 2 can be applied to point C0, where the output of the first photocoupler, which is half a wavelength ahead, changes from signal L to signal H, to generate a zero-crossing pulse. Furthermore, by recording the count values ​​during the signal H period and signal L period of the photocoupler output signal waveform, for example, when calculating the correction time length t2 / 2 near point D0 and then applying it to point F1, the zero-crossing point near point F1 can be found by adding the previously obtained count value for the H period of the first photocoupler to the count value at point C0 and subtracting the correction time length t2 / 2. With a commercial single-phase AC power supply, the zero-crossing point varies by approximately 80 μs, but the zero-crossing point can be found in advance by the time required to calculate the correction time length (almost 10 ms) minus the half-cycle time of 10 ms. The zero-crossing point near point D1 can also be found based on the count number for the L period by adding the count number for the L period to the count number for point B1 and then adding the correction time length t3 / 2. The same method can be used when a second photocoupler is used. More accurate values ​​can be obtained by using only one or both separately and comparing the values ​​obtained, or by comparing them with the calculation method of embodiment 7.

[0117] <Embodiment 8, mainly claims 10 to 12>: Momentary voltage drop detection <Outline of Embodiment 8> The eighth embodiment is based on any one of the first to seventh embodiments and is configured to also have a voltage drop detection function. <Configuration of Embodiment 6> The eighth embodiment will be described based on the seventh embodiment. Similar effects can be obtained based on the first to sixth embodiments. Fig. 19 is a functional block diagram showing an embodiment of an AC power supply interruption and voltage drop detection device (1900) according to the present embodiment. As shown in FIG. 19 , the AC power interruption and voltage drop detection device (1900) is composed of an AC power signal acquisition unit (1901), a first photocoupler (1902), a second photocoupler (1903), a time difference acquisition unit (1909), a correction time length acquisition unit (1911), a zero-cross timing acquisition unit (1910), a preemption means (1912) provided in the zero-cross timing acquisition unit (1910), a counter (1904), a comparison unit (1905), a comparison result output unit (1907), a voltage drop unit (1913), an AC full-wave rectification unit (1914), an AD conversion unit (1915), an integration unit (1916), a comparison predetermined value holding unit (1917), an abnormality / normality determination unit (1918), a determination result output unit (1919), and a microcomputer (1920). The AC power signal acquisition unit (1901), first photocoupler (1902), second photocoupler (1903), time difference acquisition unit (1909), correction time length acquisition unit (1911), zero-cross timing acquisition unit (1910), advance acquisition means (1912) provided in the zero-cross timing acquisition unit (1910), counter (1904), comparison unit (1905), and comparison result output unit (1907) that constitute the instantaneous interruption detection function are the same as those in the seventh embodiment, and therefore description thereof will be omitted. The above functional blocks are merely an example for implementing the present invention, and functions may be omitted or new functions may be added as appropriate within the scope that does not contradict the problems to be overcome by the present invention and its effects.

[0118] <Embodiment 8: Voltage drop unit (1913)> The "voltage drop section" (1913) is configured to have an isolation transformer for stepping down the AC power supply voltage. The original AC power signal is a general commercial AC power supply with a value between 85V and 264V, which is too high for electronic devices such as microcomputers, so an isolated step-down transformer is used to step it down to a manageable level of a few volts. There is a phase delay due to the inductive reactance of the transformer coil, but this is within an acceptable range for momentary voltage drop detection.

[0119] <Embodiment 8 AC Full-Wave Rectifier Unit (1914)> The "AC full-wave rectifier" (1914) is configured to full-wave rectify the AC voltage stepped down by the power supply step-down unit (1913). Rectification is performed using diodes capable of full-wave rectification of AC or other common techniques.

[0120] <Embodiment 8 AD conversion unit (1915)> The 'AD conversion unit' (1915) is configured to perform AD conversion on the full-wave rectified waveform. AD conversion is performed so that the integration part (described later) can integrate the area of ​​half the wavelength of the AC. Although it depends on the accuracy of the AD converter of the microcontroller used, a converter of about 10 bits is preferable.

[0121] <Embodiment 8: Integration section (1916)> The 'integration unit' (1916) is configured to integrate the AD converted half wavelength. The integration section integrates the section sandwiched between the voltages equivalent to 0 within the half wavelength of the AD converted signal. The zero crossing points on both sides corresponding to the corresponding half wavelength may be calculated by an AC voltage zero crossing detection circuit structure, and the time length between them may be integrated. This method is more preferable because it provides a more accurate integration interval.

[0122] <Embodiment 8: Comparison Predetermined Value Storage Unit (1917)> The 'predetermined comparison value holding unit' (1917) is configured to hold a predetermined comparison value, which is a predetermined value for determining whether the integral value of each half wavelength obtained is normal. A predetermined value is held as a criterion for determining whether a voltage drop (i.e., abnormality) is occurring or whether it is normal. For example, a voltage drop is determined to have occurred if it falls below 80% of the normal level. Since the level of voltage drop that affects the device that requires the determination result differs, it is also possible to make it selectable and settable depending on the device in question.

[0123] <Embodiment 8: Abnormal / normal determination unit (1918)> The "abnormal / normal judgment unit" (1918) is configured to compare the obtained integral value of each half wavelength with a stored predetermined comparison value and judge whether it is an abnormal voltage drop state or a normal state. The judgment is made by comparing the integration results for half a wavelength, so it is made every half a wavelength. Therefore, even if a voltage sag occurs at the moment, it will be judged as a voltage sag after half a wavelength, and even if the voltage returns to normal, it will be judged as having returned to normal after half a wavelength. It determines whether the voltage is in an abnormal voltage drop state or a normal state, but as mentioned above, the criteria for determination differ depending on the device that requires the determination result, so it is preferable to be able to switch to determining based on a selected and set predetermined comparison value. Detection of a momentary interruption begins almost immediately after its occurrence, but for a momentary sag, integration calculations are performed half a wavelength later. Therefore, there is a non-light-receiving period when no light-receiving signals are output from both photocouplers. If there is a concern about a momentary interruption, it is preferable to determine that a momentary interruption has occurred, output a momentary interruption detection signal, and not perform momentary sag detection processing. For example, if a momentary interruption is detected by the momentary interruption detection device, an interrupt process can be sent to the momentary sag detection device to stop the momentary sag detection process. Alternatively, a lower limit can be stored as a predetermined value used as a judgment standard for the comparison, and momentary sag detection can be prevented if the lower limit is reached or fallen below.

[0124] <Embodiment 8: Determination result output unit (1919)> The 'judgment result output unit' (1919) is configured to output the judgment result. If the judgment result is an abnormality (voltage drop), it is preferable to open the output (OFF potential) and to keep it ON (H potential) under normal circumstances. Voltage drops are abnormal situations, and considering situations such as a breakdown in the voltage drop detection system or a disconnection in the line transmitting the detection results, it is thought that there will be less damage if the abnormality is communicated, including the abnormality of the equipment, rather than not being communicated at all.

[0125] <Embodiment 8: AC Power Supply Signal Acquisition Unit (1901)> The 'AC power signal acquisition unit' (1901) is configured to be shared with any one of the instantaneous power interruption detection devices according to the first to seventh embodiments. The momentary interruption detection device and the momentary sag detection device share at least the AC power signal acquisition unit. Functionally, if the counter function of the microcomputer functions as the counter of the momentary interruption detection device and also performs at least one of the functions of the AD conversion unit, integration unit, comparison predetermined value holding unit, abnormality / normality determination unit, and determination result output unit of the momentary sag detection device, the number of parts can be reduced and a single device can be configured to detect momentary interruptions and momentary sags. Furthermore, when the voltage sag detection device integrates half the wavelength of the rectified AC waveform to determine a voltage sag, the zero-crossing points of the AC waveform used by the momentary interruption detection device to detect momentary interruptions can be used to determine the integration range, improving the accuracy of the integration results.This is because when full-wave rectification is performed, there is a period of 0V voltage near the zero-crossing point for a time corresponding to the operating threshold of the rectifying diode, making it difficult to accurately calculate the zero-crossing point.

[0126] <Processing flow of embodiment 8> The processing flow of this embodiment is as follows: In the comparative predetermined value holding step, a comparative predetermined value is held, which is a predetermined value for determining whether the obtained integral value for each half wavelength is normal; In the AC power supply signal acquisition step, a process of acquiring an AC power supply signal is performed; In the voltage reduction step, the AC power supply voltage is reduced by an isolation transformer. In the AC full-wave rectification step, the AC voltage stepped down in the power supply voltage step is full-wave rectified; In the AD conversion step, the full-wave rectified waveform is converted into an AD signal. In the integration step, the AD converted half wavelength is integrated. In the abnormality / normality determination step, the obtained integral value for each half wavelength is compared with a stored predetermined comparison value, and a process is performed to determine whether the state is an abnormal voltage drop state or a normal state. In the determination result output step, a process of outputting the determination result is carried out. This is an operating method for causing the power voltage dip detection device to execute a series of processes.

[0127] <Embodiment 8: Hardware Configuration> The hardware configuration of the power voltage dip detection device in this embodiment will be described with reference to FIG. 20 which shows an outline of the circuit configuration. It is composed of an AC power supply (2001), a current limiting resistor (2002), a two-circuit photocoupler (2003), a microcontroller (2004), a counter (2005), a comparison time length information holder (2006), a comparison judgment 1 (2007), a comparison result output 1 (2008), a comparison judgment 2 (2009), a comparison result output 2 (2010), a zero-cross measurement calculation (2011), a zero-cross detection output (2012), a correction time length acquisition unit (2013) within the zero-cross measurement calculation (2011), a pre-emption means (2014) within the zero-cross detection output (2012), an isolation transformer (2015), a rectifier (2016), an AD converter (2017), an integrator (2018), an integral value comparison unit (2019), a comparison predetermined value holder (2020), and a comparison result output (2021). The operation of the voltage sag detection device will be described with reference to FIGS. 20 and 21. The AC power signal is received from the AC power supply (2001), which is also used as a component for detecting momentary interruptions. The signal waveform is a sine wave, as shown in the top graph of Figure 21. Starting from the left, half-wavelengths indicate normal, abnormal, abnormal, normal, and normal. The horizontal dotted lines above and below the AC waveform indicate the upper and lower limits of the normal waveform. The voltage is reduced to a few volts by an isolation transformer (2015). After full-wave rectification by a full-wave rectifier (2016), the waveform at point e on the AD converter input side in Figure 20 is shown in the third graph from the top in Figure 21. The AC waveform is rectified entirely to the positive voltage side. The abnormal values ​​are the periods of momentary dips. In Figure 21, these represent two peaks labeled "abnormal." The figure is drawn with almost no gap between the peaks. However, because the operating threshold voltage of a diode is typically approximately 0.6 V, a period of 0 V occurs for approximately 100 μs. The full-wave rectified waveform is converted by an AD converter (2017). The obtained value is integrated by an integrator (2018). Integration is performed starting from the above-mentioned 0V voltage section until the voltage returns to the 0V section. Depending on the distortion of the waveform near 0V voltage, it is possible that a period deviated from the actual zero crossing point will be integrated. The integrated result is compared with the predetermined comparison value stored in the predetermined comparison value hold (2020), and an integrated value comparison (2019) is used to determine whether the normal value is an abnormal value. The determined result is output from the comparison result output (2021) as a voltage drop detection output. It is preferable that the output is ON (H potential) during normal times and OFF (L potential: open) during abnormal times. By combining the functionally compatible parts of the instantaneous interruption detection device and the microcontroller, it is possible to obtain a device that combines both functions with a small number of parts by simply adding an isolation transformer and full-wave rectifier. Furthermore, when integrating with the integrator (2018), the zero-cross detection output related to the zero-cross points from the AC voltage zero-cross detection circuit structure in the instantaneous interruption detection device is used to obtain and integrate the time difference (count difference) between the zero-cross points at both ends of the half wavelength to be most recently integrated, which makes the integration interval more accurate and improves precision.

[0128] <Embodiment 9>: In the case of three-phase AC <Overview of Embodiment 9> The ninth embodiment is based on the first to eighth embodiments that are intended for single-phase AC and is applied to three-phase AC. Note that the ninth embodiment can be similarly expanded from single phase to other phases (two-phase AC, etc.). <Configuration of Embodiment 9> A momentary interruption and / or momentary sag detection device for three-phase AC can be configured by using three single-phase devices for each phase or for three combinations between two different phases. When detecting momentary interruptions and / or momentary sags, a detection device can be installed for one phase or one type of two-phase voltage, but more accurate detection can be achieved by installing three types of detection devices corresponding to each of the three phases or three combinations between two different phases. This is because there is a possibility that the wiring of one of the three phases may be broken. [Explanation of symbols]

[0129] Power interruption detection device...0300 AC power supply…0301 Current limiting resistor...0302 Dual-circuit photocoupler...0303 First photocoupler...0303a Second photocoupler...0303b Microcomputer…0304 Pulse measurement using a counter...0305 Zero crossing measurement calculation...0306 Comparison judgment…0307 Comparison time length information retention…0308 Zero cross detection output...0309 Comparison result output...0310

Claims

1. an AC power signal acquisition unit that acquires an AC power signal; a power supply step-down unit having an isolation transformer for stepping down an AC power supply voltage; an AC full-wave rectification unit that full-wave rectifies the AC voltage stepped down by the power supply voltage step-down unit; an AD conversion unit that performs AD conversion on the full-wave rectified waveform; An integration section that integrates the AD converted half wavelength. A predetermined comparison value is a predetermined value for determining whether the integral value of each half wavelength obtained is normal. a comparison predetermined value storage unit for storing the comparison predetermined value; an abnormality / normality determination unit that compares the obtained integral value for each half wavelength with a stored predetermined comparison value and determines whether the state is an abnormal voltage sag state or a normal state; a determination result output unit that outputs the determination result determined by the abnormal / normal determination unit; a first photocoupler that outputs a light reception signal when the acquired AC power supply signal is positive and does not output a light reception signal when the acquired AC power supply signal is negative; a second photocoupler that does not output a light reception signal when the acquired AC power supply signal is positive, and that outputs a light reception signal when the acquired AC power supply signal is negative; a counter for counting a signal width, which is an arbitrary time interval of the AC power signal; a comparison time length information storage unit that stores a plurality of pieces of comparison time length information, which is information indicating a predetermined time length to be compared with non-light receiving time length information, which is information indicating a value counted by the counter during a period when no light receiving signal is acquired from either the first photocoupler or the second photocoupler; a comparison unit that compares the non-light-receiving time length information with a plurality of pieces of comparison time length information; a comparison result output unit that outputs a predetermined comparison result for each comparison result when the plurality of comparison results in the comparison unit are the predetermined comparison result; moreover, the first photocoupler is configured to output a signal L when the acquired AC power supply signal is positive, and to output a signal H when the acquired AC power supply signal is negative; the second photocoupler is configured to output a signal H in response to a positive value of the acquired AC power supply signal, and to output a signal L in response to a negative value of the acquired AC power supply signal; "The time difference between the first timing at which the signal of the second photocoupler switches from L to H and the second timing at which the signal of the first photocoupler switches from H to L in the same timing region where the AC power supply signal is inverted from negative to positive" or / and, a time difference acquiring unit that acquires "a time difference between a third timing at which the signal of the second photocoupler switches from H to L and a fourth timing at which the signal of the first photocoupler switches from L to H in the same timing region where the AC power supply signal is inverted in polarity"; a zero-cross timing acquisition unit that acquires timings when the voltage of the AC power signal is zero using a corrected time length that is half the time length of the acquired time difference; a corrected time length acquisition unit that statistically processes a plurality of acquired time differences to acquire a corrected time length; and In the correction time length acquisition unit, the time lengths obtained by multiplying the acquired multiple time differences by 1 / 2 are accumulated and held, and statistically processed to obtain the correction time lengths, and if the time length obtained by multiplying the acquired time difference by 1 / 2 falls outside the range of expected maximum and minimum values ​​of the correction time length obtained from the correction time lengths, this value is excluded from the correction of the zero crossing point half a wavelength later, and the same value as the previous time is used as the provisional correction time length.

2. The counter according to claim 1, 2. The power voltage dip detector according to claim 1, wherein at least one of the AD conversion unit, the integration unit, the comparison predetermined value holding unit, the abnormality / normality determination unit, and the determination result output unit are functionally integrated into the same microcomputer.

3. The power instantaneous dip detection device according to claim 1 , wherein the zero crossing points are used when integrating over a half wavelength.

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