Voltage detection circuit, method and electrical equipment

Abstract

The present invention discloses a voltage detection circuit, method and electrical equipment. The circuit includes: a first detection unit, whose input end is connected to the output end of an AC power supply, whose output end is connected to a logic operation unit, and is used to output a signal according to the output voltage of the AC power supply; a second detection unit, whose input end is connected to the output end of the AC power supply, whose output end is connected to the logic operation unit, and is used to output a signal according to the output voltage of the AC power supply; a logic operation unit, which is used to generate a PWM signal according to the signals output by the first detection unit and the second detection unit; a waveform detection unit, whose input end is connected to the logic operation unit, and is used to determine a preset time period according to the PWM signal; wherein, within the preset time period, the output voltage of the AC power supply is between the second threshold value and the first threshold value. Through the present invention, it is possible to accurately control the timing of load action according to the waveform characteristics of the AC power supply to avoid impact on the load.

Description

Technical Field

[0001] The present invention relates to the field of electronic power technology, and in particular to a voltage detection circuit, method and electrical equipment. Background Art

[0002] Existing electrical equipment (such as various refrigeration equipment and devices) has a large number of high-power loads that need to be powered by AC power. In the load circuit powered by AC power, zero-crossing detection and low-voltage startup are usually performed to protect the load and control devices and their control circuits. The purpose of the above operation is to reduce the impact current during the startup and shutdown process, thereby protecting the load and control circuit.

[0003] However, currently, there are only zero-crossing and low-voltage detections for AC power supply detection, and the time period corresponding to a certain voltage range cannot be obtained, and thus the timing of starting, running and shutting down the load cannot be accurately controlled according to the waveform characteristics of the AC power supply.

[0004] With respect to the problem in the prior art that the timing of load action cannot be accurately controlled according to the waveform characteristics of the AC power supply, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present invention provide a voltage detection circuit, method and electrical equipment to solve the problem in the prior art that the timing of load action cannot be accurately controlled according to the waveform characteristics of the AC power supply.

[0006] In order to solve the above technical problems, the present invention provides a voltage detection circuit, wherein the circuit comprises:

[0007] A first detection unit, whose input end is connected to the output end of the AC power supply, and whose output end is connected to the logic operation unit, and is used to output a signal according to the output voltage of the AC power supply;

[0008] a second detection unit, whose input end is connected to the output end of the AC power supply, and whose output end is connected to the logic operation unit, and is used to output a signal according to the output voltage of the AC power supply;

[0009] The logic operation unit is used to generate a pulse width modulation (PWM) signal according to the signals output by the first detection unit and the second detection unit;

[0010] A waveform detection unit, whose input end is connected to the logic operation unit, is used to determine a preset time period according to the PWM signal; wherein, within the preset time period, the output voltage of the AC power supply is between the second threshold and the first threshold.

[0011] Furthermore, the first detection unit includes: a first comparator and a first reference voltage source; the inverting input terminal of the first comparator is connected to the first reference voltage source, and the non-inverting input terminal is connected to the output terminal of the AC power supply;

[0012] The second detection unit includes: a second comparator and a second reference voltage source; the inverting input terminal of the second comparator is connected to the second reference voltage source, and the non-inverting input terminal is connected to the output terminal of the AC power supply.

[0013] Furthermore, the first reference voltage source includes: a first resistor and a second resistor, the first resistor and the second resistor are connected in series and connected to the first voltage source; the inverting input terminal of the first comparator is connected between the first resistor and the second resistor;

[0014] The second reference voltage source includes: a third resistor and a fourth resistor, wherein the third resistor and the fourth resistor are connected in series and then connected to the second voltage source; and the inverting input terminal of the second comparator is connected between the third resistor and the fourth resistor.

[0015] Furthermore, the voltage provided by the second reference voltage source is smaller than the voltage provided by the first reference voltage source.

[0016] Furthermore, the logic operation unit includes an XOR gate chip, which is used to output a low level when the signals output by the first detection unit and the second detection unit are the same; and output a high level when the signals output by the first detection unit and the second detection unit are opposite.

[0017] Furthermore, the waveform detection unit is specifically used to determine a high level period of the PWM signal as the preset period.

[0018] Furthermore, the circuit further comprises:

[0019] An operational amplifier unit, wherein an input end thereof is connected to an output end of the AC power supply, and an output end thereof is respectively connected to the first detection unit and the second detection unit.

[0020] Furthermore, the operational amplifier unit includes: an operational amplifier, wherein the non-inverting input terminal of the operational amplifier is connected to the output terminal of the AC power supply, the inverting input terminal is connected to its own output terminal, the positive pole of the power supply is connected to the third voltage source, and the negative pole of the power supply is connected to the reference ground; the output terminal of the operational amplifier is also connected to the first detection unit and the second detection unit respectively.

[0021] Furthermore, the operational amplifier unit further includes: a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; the fifth resistor is connected between the non-inverting input terminal of the operational amplifier and the output terminal of the AC power supply, one end of the sixth resistor is connected between the fifth resistor and the non-inverting input terminal of the operational amplifier, and the other end is connected to a fourth voltage source, the seventh resistor is connected between the output terminal and the inverting input terminal of the operational amplifier, and the eighth resistor is connected between the output terminal of the operational amplifier and the reference ground.

[0022] Furthermore, the circuit further comprises:

[0023] a ninth resistor, one end of which is connected between the first detection unit and the logic operation unit, and the other end of which is connected to a reference ground;

[0024] A tenth resistor, one end of the tenth resistor is connected between the second detection unit and the logic operation unit, and the other end of the tenth resistor is connected to a reference ground.

[0025] The present invention also provides an electrical device, comprising the voltage detection circuit.

[0026] Furthermore, the electrical equipment includes at least one of the following:

[0027] Air conditioners, washing machines, refrigerators, water heaters, fans, dryers, air purifiers, water purifiers, and water purifiers.

[0028] The present invention also provides a voltage detection method, which is applied to the above voltage detection circuit, and the method comprises:

[0029] Acquire a PWM signal output by the logic operation unit; wherein the PWM signal is generated according to the signals output by the first detection unit and the second detection unit;

[0030] Determine a preset time period according to the PWM signal; wherein, within the preset time period, the output voltage of the AC power supply is between a second threshold value and a first threshold value;

[0031] During the preset time period, the electrical equipment is controlled to start or stop.

[0032] Further, determining a preset time period according to the PWM signal includes:

[0033] A high level period of the PWM signal is determined as the preset period.

[0034] Furthermore, within the preset time period, controlling the electrical equipment to start or stop includes:

[0035] After receiving an instruction to start or stop the electric device, determining whether the current time is in the preset time period;

[0036] If yes, control the electrical equipment to start or stop;

[0037] If not, the electric device is controlled to maintain the current operating state until the current moment is within the preset time period, and then the electric device is triggered to start or stop.

[0038] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the voltage detection method is implemented.

[0039] By applying the technical solution of the present invention, two detection units are used to generate output signals to a logic operation unit according to the AC power signal respectively; a PWM signal is generated according to the output signals of the above two detection units by the logic operation unit; and a waveform detection unit is used to determine a preset time period corresponding to when the output voltage of the AC power supply is between the second threshold value and the first threshold value according to the PWM signal, and then the load is controlled within the preset time period, so that the timing of load action can be accurately controlled according to the waveform characteristics of the AC power supply to avoid impact on the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a structural diagram of a voltage detection circuit according to an embodiment of the present invention;

[0041] Figure 2 is a structural diagram of a voltage detection circuit according to another embodiment of the present invention;

[0042] Figure 3 is a waveform diagram of an output signal of a first comparator according to an embodiment of the present invention;

[0043] Figure 4 is a waveform diagram of an output signal of a second comparator according to an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of generating a PWM signal according to an embodiment of the present invention;

[0045] Figure 6 FIG. 4 is a flow chart of a voltage detection method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0048] It should be understood that the term "and / or" used in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0049] It should be understood that although the terms first, second, etc. may be used to describe the detection units in the embodiments of the present invention, these detection units should not be limited to these terms. These terms are only used to distinguish different detection units. For example, without departing from the scope of the embodiments of the present invention, the first detection unit may also be referred to as the second detection unit, and similarly, the second detection unit may also be referred to as the first detection unit.

[0050] As used herein, the words "if" and "if" may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0051] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0052] The optional embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0053] Example 1

[0054] This embodiment provides a voltage detection circuit. Figure 1 is a structural diagram of a voltage detection circuit according to an embodiment of the present invention, Figure 1As shown, the voltage detection circuit includes: a first detection unit 10, the input end of the first detection unit 10 is connected to the output end of the AC power supply AC, and the output end is connected to the logic operation unit 30, which is used to output a signal according to the output voltage of the AC power supply AC; a second detection unit 20, the input end of the second detection unit 20 is connected to the output end of the AC power supply AC, and the output end is connected to the logic operation unit 30, which is used to output a signal according to the output voltage of the AC power supply AC; the logic operation unit 30 is used to generate a PWM (Pulse Width Modulation) signal according to the signals output by the first detection unit 10 and the second detection unit 20; a waveform detection unit 40, the input end of the waveform detection unit 40 is connected to the logic operation unit 30, which is used to determine a preset time period according to the PWM signal output by the logic operation unit 30; wherein, within the above-mentioned preset time period, the output voltage of the AC power supply is between the second threshold value and the first threshold value.

[0055] Specifically, in the present embodiment, the signals output by the first detection unit 10 and the second detection unit 20 can reflect the output voltage value of the AC power supply. Based on the change in the output voltage value of the AC power supply, the first detection unit 10 and the second detection unit 20 can output different signals. The logic operation unit 30 generates a PWM signal according to the different signals output by the first detection unit 10 and the second detection unit 20. That is to say, the output voltage of the AC power supply exceeding a certain range will cause the waveform of the generated PWM signal to change. Therefore, the change in the voltage value output by the AC power supply can also be inferred through the waveform of the PWM signal.

[0056] The voltage detection circuit of this embodiment generates output signals to the logic operation unit according to the AC power signal through two detection units; generates a PWM signal according to the output signals of the above two detection units through the logic operation unit; and determines the corresponding preset time period when the output voltage of the AC power supply is between the second threshold value and the first threshold value according to the PWM signal through the waveform detection unit, and then controls the load within the preset time period, so as to achieve accurate control of the timing of load action according to the waveform characteristics of the AC power supply to avoid impact on the load.

[0057] Example 2

[0058] This embodiment provides another voltage detection circuit. Figure 2 FIG. 4 is a structural diagram of a voltage detection circuit according to another embodiment of the present invention. Figure 2 As shown, the first detection unit 10 includes: a first comparator A1 and a first reference voltage source 101, the first reference voltage source 101 is used to provide a first reference voltage Vref1; the inverting input terminal N- of the first comparator A1 is connected to the first reference voltage source, and the non-inverting input terminal IN+ is connected to the output terminal of the AC power supply.

[0059] Figure 3 : is a waveform diagram of an output signal of the first comparator A1 according to an embodiment of the present invention. Figure 3 As shown, when the output voltage of the AC power supply is less than the first threshold, the input voltage of the in-phase input terminal of the first comparator A1 is less than the first reference voltage Vref1, and a low-level signal is output. When the output voltage of the AC power supply is greater than the first threshold, the input voltage of the in-phase input terminal of the first comparator A1 is greater than the first reference voltage Vref1, and a high-level signal is output, and finally the cosine signal output by the AC power supply is converted into a square wave signal. In the absence of an operational amplifier, the first threshold and the first reference voltage Vref1 can be equal.

[0060] The second detection unit 20 includes: a second comparator A2 and a second reference voltage source 201, the second reference voltage source 201 is used to provide a second reference voltage Vref2; the inverting input terminal N- of the second comparator A2 is connected to the second reference voltage source 201, and the non-inverting input terminal IN+ is connected to the output terminal of the AC power supply AC.

[0061] Figure 4 : is a waveform diagram of an output signal of the second comparator A2 according to an embodiment of the present invention. Figure 4 As shown, when the output voltage of the AC power supply is less than the second threshold value, the input voltage of the in-phase input terminal of the second comparator A2 is less than the second reference voltage Vref2, and a low-level signal is output; when the output voltage of the AC power supply is greater than the second threshold value, the input voltage of the in-phase input terminal of the second comparator A2 is greater than the second reference voltage Vref2, and a high-level signal is output, and finally the cosine signal output by the AC power supply is converted into a square wave signal. Wherein, in the absence of an operational amplifier, the second threshold value and the second reference voltage Vref2 may be equal.

[0062] In order to obtain the required reference voltage, the first reference voltage source can be obtained by dividing the voltage source by resistors with different resistance values, such as Figure 2As shown, the above-mentioned first reference voltage source 101 includes: a first voltage source VCC1, a first resistor R1 and a second resistor R2, the first resistor R1 and the second resistor R2 are connected in series and connected to the first voltage source VCC1, a first reference voltage Vref1 is output between the first resistor R1 and the second resistor R2, the first reference voltage Vref1 is input to the inverting input terminal IN- of the first comparator A1, the positive power supply electrode VS+ of the first comparator A1 is also connected to the first voltage source VCC1, and the negative power supply electrode VS- is connected to the reference ground; similarly, the above-mentioned second reference voltage source 201 includes: a second voltage source VCC2, a third resistor R3 and a fourth resistor R4, the third resistor R3 and the fourth resistor R4 are connected in series and connected to the second voltage source VCC2, a second reference voltage Vref2 is output between the third resistor R3 and the fourth resistor R4, the second reference voltage Vref2 is input to the inverting input terminal IN- of the second comparator A2, the positive power supply electrode VS+ of the second comparator A2 is also connected to the second voltage source VCC2, and the negative power supply electrode VS- is connected to the reference ground.

[0063] In order to obtain different high-level pulse widths, the second reference voltage Vref2 is less than the first reference voltage Vref1, so that the second comparator A2 starts to output a high level earlier than the first comparator A1, and stops outputting a high level later than the first comparator A1, so that the continuous logic operation unit 30 generates a PWM signal that outputs high and low levels at intervals.

[0064] In order to achieve the purpose of generating a PWM signal that outputs high and low levels at intervals, the logic operation unit 30 includes an XOR gate chip IC1, and the XOR gate chip IC1 is used to output a low level when the signals output by the first detection unit 10 and the second detection unit 20 are the same, that is, the first detection unit 10 and the second detection unit 20 both output a high level or both output a low level; and output a high level when the signals output by the first detection unit 10 and the second detection unit 20 are opposite, that is, one of the first detection unit 10 and the second detection unit 20 outputs a low level and the other outputs a high level. Figure 5 FIG. 4 is a schematic diagram of a PWM signal generation principle according to an embodiment of the present invention, as shown in FIG. Figure 5As shown, in the first time period, the first comparator A1 and the second comparator A2 both output a low level, and the logic operation unit 30 outputs a low level. After entering the second time period, the second comparator A2 starts to output a high level, and the first comparator A1 still outputs a low level. At this time, the logic operation unit 30 outputs a high level. After entering the third time period, the first comparator A1 starts to output a high level, and the second comparator A2 still outputs a high level. At this time, the logic operation unit 30 starts to output a low level. After entering the fourth time period, the first comparator A1 starts to output a low level, and the second comparator A2 still outputs a high level, then the logic operation unit 30 starts to output a high level again, and this rule is repeated. Through the above analysis, in the second time period and the fourth time period, the logic operation unit 30 outputs a high level, indicating that the voltage value output by the AC power supply AC is between the second threshold value and the first threshold value.

[0065] The waveform detection unit 40 determines the high-level period of the PWM signal output by the logic operation unit 30, i.e., the second period and the fourth period mentioned above, as a preset period. During the preset period, the voltage value output by the alternating current power source AC is between the second threshold value and the first threshold value, and the load, i.e., the electrical equipment, can be controlled to perform a shutdown or startup operation during this period.

[0066] Since the signal output by the AC power supply is a strong electric signal with a high amplitude, and components such as comparators need to work under weak current, Figure 2 As shown, the above circuit also includes: an operational amplifier unit 50, the input end of the operational amplifier unit 50 is connected to the output end of the alternating current power supply AC, and the output end thereof is respectively connected to the first detection unit 10 and the second detection unit 20. The operational amplifier unit 50 functions to reduce the voltage output by the alternating current power supply AC and then output it to the first detection unit 10 and the second detection unit 20; specifically, the operational amplifier unit 50 includes: an operational amplifier U, the in-phase input end IN+ of which is connected to the output end of the alternating current power supply AC, the inverting input end of which is connected to its own output end out, and the output end out of which is also connected to the in-phase input end IN+ of the first comparator A1 and the second comparator A2, the positive power supply VS+ of which is connected to the third voltage source VSS, and the negative power supply VS- of which is connected to the reference ground.

[0067] Since the input currents of operational amplifiers, comparators and other components all have maximum limits, current limiting is required to avoid excessive current in the circuit, which may cause the above components to malfunction. In order to achieve the purpose of current limiting, the above operational amplifier unit 50 also includes: a fifth resistor R5, which is connected between the in-phase input terminal IN+ of the operational amplifier U and the output terminal of the AC power supply AC, and is used to limit the input current of the operational amplifier U.

[0068] At the same time, in order to achieve the voltage division effect, such as Figure 2As shown, the operational amplifier unit 50 further includes a sixth resistor R6, a seventh resistor R7 and an eighth resistor R8; one end of the sixth resistor R6 is connected between the fifth resistor R5 and the in-phase input terminal IN+ of the operational amplifier U, and the other end is connected to the fourth voltage source VDD, for controlling the input voltage of the in-phase input terminal IN+ of the operational amplifier U; the seventh resistor R7 is connected between the output terminal out of the operational amplifier U and its own inverting input terminal IN-, for controlling the voltage of the inverting input terminal IN- of the operational amplifier U; the eighth resistor R8 is connected between the output terminal out of the operational amplifier U and the reference ground, for controlling the voltage of the output terminal out of the operational amplifier U.

[0069] In order to limit the input voltage of XOR gate chip IC1, such as Figure 2 As shown, the above circuit also includes: a ninth resistor R9, one end of the ninth resistor R9 is connected between the first detection unit 10 and the logic operation unit 30, and the other end is connected to the reference ground; a tenth resistor R10, one end of the tenth resistor R10 is connected between the second detection unit 20 and the logic operation unit 30, and the other end is connected to the reference ground.

[0070] Example 3

[0071] This embodiment provides another voltage detection circuit. The structure of the voltage detection circuit of this embodiment is as shown in the above. Figure 2 As shown, in this embodiment, by setting the resistance values ​​of the first resistor R1 and the second resistor R2, the first reference voltage Vref1 is 3V, and by the resistance values ​​of the third resistor R3 and the fourth resistor R4, the second reference voltage Vref2 is 2V, the resistance value of the fifth resistor R5 is 1MΩ, the resistance value of the sixth resistor R6 is 2.4kΩ, and the resistance values ​​of the seventh resistor R7, the eighth resistor R8, the ninth resistor R9 and the tenth resistor R10 are all 10kΩ.

[0072] The first comparator A1 and the second comparator A2 are both of type LMC7211BIM5, the operational amplifier U is of type LM258AD, the XOR gate chip IC1 is of type 74LS86N, the voltage provided by the first voltage source VCC1 and the second voltage source VCC2 is 5V; the voltage provided by the third voltage source VSS is 12V, the voltage provided by the fourth voltage source VDD is 2.5V, and the input signal Vin and the output signal Vout of the operational amplifier satisfy the following relationship:

[0073]

[0074] The voltage detection circuit of this embodiment converts the signal output by the input AC power supply into a low-voltage PWM waveform through the operational amplifier unit, the first comparator A1, the second comparator A2 and the XOR gate chip IC1, so as to characterize the output signal of the AC power supply through the PWM waveform, thereby determining the corresponding time period when the output voltage value of the AC power supply is between the second threshold value and the first threshold value according to the PWM waveform, and then controlling the load within the time period.

[0075] This embodiment controls the load to perform a certain operation within a certain voltage range, reduces the startup impact current of the AC power supply load, reduces the overcurrent of the startup control device, and prolongs the service life; reduces the shutdown impact current of the AC power supply to the load, reduces the overshoot current of the shutdown circuit, and prolongs the life of the control device; reduces the impact current when the load is started and shut down, and protects the load. The phase information of the cosine signal output by the AC power supply is converted into time domain information through the PWM wave, which is used to characterize the voltage amplitude characteristics of the AC power supply, that is, the output voltage value of the AC power supply can be monitored in real time according to the PWM signal, which is used to control the timing of starting and shutting down the strong electric load, reduce the impact of the impact current, and prevent the potential danger caused by the power supply voltage fluctuation during the operation of the load; in addition, through the circuit structure of this embodiment, the complexity of program processing can be reduced and the program processing circuit can be simplified.

[0076] Example 4

[0077] This embodiment provides a voltage detection method, which is applied to the above voltage detection circuit. Figure 6 : is a flow chart of a voltage detection method according to an embodiment of the present invention. Figure 6 As shown, the method includes:

[0078] S101, obtaining a PWM signal output by a logic operation unit; wherein the PWM signal is generated according to signals output by a first detection unit and a second detection unit.

[0079] Through the XOR gate chip in the logic operation unit, when both the first detection unit and the second detection unit output a high level or both output a low level, a low level is output; when one of the first detection unit and the second detection unit outputs a low level and the other outputs a high level, a high level is output. As mentioned above Figure 5As shown in, in the first time period, the first comparator and the second comparator both output a low level, and the logic operation unit outputs a low level. After entering the second time period, the second comparator starts to output a high level, and the first comparator still outputs a low level. At this time, the logic operation unit outputs a high level. After entering the third time period, the first comparator starts to output a high level, and the second comparator still outputs a high level. At this time, the logic operation unit starts to output a low level. After entering the fourth time period, the first comparator starts to output a low level, and the second comparator still outputs a high level, then the logic operation unit starts to output a high level again, and this pattern is repeated.

[0080] S102, determining a preset time period according to the PWM signal; wherein, within the preset time period, the output voltage of the AC power supply is between the second threshold and the first threshold.

[0081] As described above, during the second time period and the fourth time period, the logic operation unit outputs a high level, indicating that the voltage value output by the AC power supply AC is between the second threshold value and the first threshold value. Therefore, the time period when the logic operation unit outputs a high level, that is, the high level time period of the PWM signal, is used as the preset time period.

[0082] S103, controlling the electrical equipment to start or stop within a preset time period.

[0083] During the preset time period, the output voltage of the AC power supply is between the second threshold value and the first threshold value. At this time, the power-consuming device is controlled to start or stop, which can avoid impact on the power-consuming device. Therefore, after receiving the instruction to control the power-consuming device to start or stop, it is determined whether the current moment is in the above-mentioned preset time period; if so, it means that the voltage output by the AC power supply is between the second threshold value and the first threshold value, within the preset range, at this time, the power-consuming device can be directly controlled to start or stop; if not, it means that the voltage output by the AC power supply is not between the second threshold value and the first threshold value, that is, not within the preset range, at this time, the power-consuming device should be controlled to maintain the current operating state until the current moment is in the preset time period, and then the power-consuming device is triggered to start or stop.

[0084] The voltage detection method of this embodiment is based on the voltage detection circuit in the above embodiment. The strong electric signal output by the AC power supply passes through the operational amplifier unit, and then is output to the first detection unit and the second detection unit, and finally is output to the logic operation unit.

[0085] Specifically, by setting different resistance values ​​of the fifth resistor and the sixth resistor, the high voltage output by the AC power source is converted into a low voltage, and the low voltage range value of the input power signal is determined.

[0086] The duty cycle of the generated PWM signal is determined by setting the value of the first reference voltage and the value of the second reference voltage.

[0087] By extracting the high-level period of the PWM signal, the time period corresponding to when the voltage value output by the operational amplifier unit is between the second reference voltage and the first reference voltage can be obtained, that is, the time period corresponding to when the output voltage of the AC power supply is between the second threshold value and the first threshold value. The information of the signal output by the operational amplifier unit is obtained through the PWM signal and the time domain, and then the output voltage information of the AC power supply is obtained.

[0088] The voltage detection method of this embodiment obtains the PWM signal output by the logic operation unit; generates a PWM signal according to the output signals of the above two detection units through the logic operation unit; determines the preset time period corresponding to when the output voltage of the AC power supply is between the second threshold value and the first threshold value according to the PWM signal through the waveform detection unit, and then controls the load within the preset time period, so as to achieve accurate control of the timing of load action according to the waveform characteristics of the AC power supply to avoid impact on the load.

[0089] Example 5

[0090] This embodiment provides an electrical device, which includes the above-mentioned voltage detection circuit, which is used to determine the corresponding time period when the output voltage of the AC power supply is between the second threshold and the first threshold, and control the electrical device to perform a start or stop operation during the time period to avoid impact on the electrical device.

[0091] The above-mentioned electrical equipment includes at least one of the following: air conditioner, washing machine, refrigerator, water heater, fan, dryer, air purifier, water purifier, and water purifier.

[0092] Example 6

[0093] This embodiment provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned voltage detection method is implemented.

[0094] The circuit embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0095] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A voltage detection circuit, characterized in that: The circuit comprises: A first detection unit, whose input end is connected to the output end of the AC power supply, and whose output end is connected to the logic operation unit, and is used to output a signal according to the output voltage of the AC power supply; a second detection unit, whose input end is connected to the output end of the AC power supply, and whose output end is connected to the logic operation unit, and is used to output a signal according to the output voltage of the AC power supply; The logic operation unit is used to generate a pulse width modulation (PWM) signal according to the signals output by the first detection unit and the second detection unit; A waveform detection unit, whose input end is connected to the logic operation unit, is used to determine a preset time period according to the PWM signal; wherein, within the preset time period, the output voltage of the AC power supply is between the second threshold and the first threshold, and within the preset time period, the electrical equipment is controlled to start or stop.

2. The circuit according to claim 1, characterized in that The first detection unit includes: a first comparator and a first reference voltage source; the inverting input terminal of the first comparator is connected to the first reference voltage source, and the non-inverting input terminal is connected to the output terminal of the AC power supply; The second detection unit includes: a second comparator and a second reference voltage source; the inverting input terminal of the second comparator is connected to the second reference voltage source, and the non-inverting input terminal is connected to the output terminal of the AC power supply.

3. The circuit according to claim 2, characterized in that The first reference voltage source includes: a first resistor and a second resistor, wherein the first resistor and the second resistor are connected in series and then connected to a first voltage source; an inverting input terminal of the first comparator is connected between the first resistor and the second resistor; The second reference voltage source includes: a third resistor and a fourth resistor, wherein the third resistor and the fourth resistor are connected in series and then connected to the second voltage source; and the inverting input terminal of the second comparator is connected between the third resistor and the fourth resistor.

4. The circuit according to claim 3, characterized in that The voltage provided by the second reference voltage source is smaller than the voltage provided by the first reference voltage source.

5. The circuit according to claim 1, characterized in that The logic operation unit includes an XOR gate chip, which is used to output a low level when the signals output by the first detection unit and the second detection unit are the same; and output a high level when the signals output by the first detection unit and the second detection unit are opposite.

6. The circuit according to claim 5, characterized in that The waveform detection unit is specifically used to determine a high level period of the PWM signal as the preset period.

7. The circuit according to claim 1, characterized in that The circuit further comprises: An operational amplifier unit, wherein an input end thereof is connected to an output end of the AC power supply, and an output end thereof is respectively connected to the first detection unit and the second detection unit.

8. The circuit according to claim 7, characterized in that The operational amplifier unit includes: an operational amplifier, wherein the non-inverting input terminal of the operational amplifier is connected to the output terminal of the AC power supply, the inverting input terminal is connected to its own output terminal, the positive pole of the power supply is connected to the third voltage source, and the negative pole of the power supply is connected to the reference ground; the output terminal of the operational amplifier is also connected to the first detection unit and the second detection unit respectively.

9. The circuit according to claim 8, characterized in that The operational amplifier unit further includes: a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; the fifth resistor is connected between the non-inverting input terminal of the operational amplifier and the output terminal of the AC power supply, one end of the sixth resistor is connected between the fifth resistor and the non-inverting input terminal of the operational amplifier, and the other end is connected to a fourth voltage source, the seventh resistor is connected between the output terminal and the inverting input terminal of the operational amplifier, and the eighth resistor is connected between the output terminal of the operational amplifier and the reference ground.

10. The circuit according to claim 1, characterized in that The circuit further comprises: a ninth resistor, one end of which is connected between the first detection unit and the logic operation unit, and the other end of which is connected to a reference ground; A tenth resistor, one end of the tenth resistor is connected between the second detection unit and the logic operation unit, and the other end of the tenth resistor is connected to a reference ground.

11. An electrical device, characterized in that: The invention comprises the voltage detection circuit according to any one of claims 1 to 10.

12. The electrical equipment according to claim 11, characterized in that: The electrical equipment includes at least one of the following: Air conditioners, washing machines, refrigerators, water heaters, fans, dryers, air purifiers, water purifiers, and water purifiers.

13. A voltage detection method, applied to the voltage detection circuit according to any one of claims 1 to 10, characterized in that: The method comprises: Acquire a PWM signal output by the logic operation unit; wherein the PWM signal is generated according to the signals output by the first detection unit and the second detection unit; Determine a preset time period according to the PWM signal; wherein, within the preset time period, the output voltage of the AC power supply is between a second threshold value and a first threshold value; During the preset time period, the electrical equipment is controlled to start or stop.

14. The method according to claim 13, characterized in that Determining a preset time period according to the PWM signal includes: A high level period of the PWM signal is determined as the preset period.

15. The method according to claim 13, characterized in that Controlling the start or stop of electrical equipment during the preset time period includes: After receiving an instruction to start or stop the electric device, determining whether the current time is in the preset time period; If yes, control the electrical equipment to start or stop; If not, the electric device is controlled to maintain the current operating state until the current moment is within the preset time period, and then the electric device is triggered to start or stop.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 13 to 15 is implemented.

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