Control device, heating device using said control device, and control method of said control device

Abstract

A microcontroller of a controller unit comprises a detection unit, a timekeeping unit, a determination unit, and a calculation unit. The detection unit receives an open / closed state signal and detects a change edge. The timekeeping unit measures a delay time T from the transmission of an opening / closing control signal until the detection of a change edge. The determination unit determines, by means of T, whether the change edge is a relay state change. When it is determined that the change edge is a relay state change, the calculation unit computes the time between two contiguous zero-crossings of an AC power source to be a relay control start time Ts using T and a time between zero-crossings Tz. When it is determined that the change edge is not a relay state change, the calculation unit adds a first constant (N1) multiple (N1 is a natural number) of Tz to Ts, and then carries out transmission of the opening / closing control signal and determination of the relay state change, and re-computes Ts.

Description

Control device, heating device using said control device, and control method for said control device

[0001] The present disclosure relates to a control device, a heating device using the control device, and a control method for the control device.

[0002] Patent Document 1 discloses a relay control device that controls a relay using a zero-cross point waveform. The relay control device described in Patent Document 1 includes a frequency detection unit, a zero-cross point detection unit, an AC period detection unit, and a relay operation delay time calculation unit.

[0003] The AC period detector detects the time between two consecutive zero crossing points among the zero crossing points detected by the zero crossing point detector, i.e., approximately half a period of the AC power supply, and thereby calculates the period of the AC power supply.

[0004] The relay operation delay time calculation unit determines the timing to output a relay operation signal based on the AC period and the rated relay operation delay time. The relay operation delay time calculation unit outputs the relay operation signal after a virtual relay control delay time from a starting point, which is an arbitrary zero crossing point. Furthermore, the relay operation delay time calculation unit calculates a true relay operation delay time from the output of the relay operation signal to the actual operation of the relay contact.

[0005] Patent Document 2 discloses a method for adjusting the temperature of a base of an electric iron using a relay control device. The iron described in Patent Document 2 includes a heating unit, a temperature detection unit, a temperature setting unit, a control unit, a relay, a switching element, a power supply circuit for the relay, and a contact detection unit.

[0006] The heating unit heats the base. The temperature detection unit detects the temperature of the base. The control unit compares the output of the temperature detection unit with the output of the temperature setting unit and controls the temperature of the base. The relay controls the supply of electricity to the heating unit. The switching element drives the relay. The power supply circuit for the relay has a rectifying diode and a capacitor. The contact detection unit detects the opening and closing of the relay contacts within a predetermined time from the zero-cross point of the AC power supply.

[0007] The control unit stops driving the switching element when an ON signal is output to the switching element and the signal from the contact detection means indicates that the contact is open.

[0008] JP 2005-216649 JP 9-201500

[0009] The present disclosure aims to provide a control device and a control method for the control device that calculates a control start time and performs highly accurate zero-cross control even when the operational delay time of a relay exceeds the time between two zero-cross points.

[0010] Furthermore, the present disclosure has an object to provide a heating device with improved heating performance by using the control device to perform temperature control with highly accurate zero-cross control.

[0011] According to one aspect of the present disclosure, there is provided a control device for controlling a relay, the control device including a ZVP waveform generating unit, a control unit, and a relay state detecting unit.

[0012] The ZVP waveform generation unit generates a zero-cross point waveform that indicates the point in time at which the waveform of the AC power supply becomes 0 V, based on the waveform of the AC power supply. The control unit sets the zero-cross point obtained from the zero-cross point waveform as a reference time point, and performs zero-cross control by transmitting a control signal to the relay after a control start time from this reference time point. The relay state detection unit detects the state of the relay and transmits a state signal.

[0013] The control unit includes a detection unit, a timer unit, a determination unit, and a calculation unit. The detection unit receives the status signal after transmitting the control signal and detects a rising edge or a falling edge of the status signal as a changing edge. The timer unit measures the delay time from transmitting the control signal to detecting the changing edge. The determination unit determines whether the changing edge is a state change of the relay based on the delay time.

[0014] When the transition edge of the open / close state signal is determined to be a state change of the relay, the calculation unit calculates the control start time from the zero-crossing point interval time and the delay time. The zero-crossing point interval time is the time between two consecutive zero-crossing points.

[0015] When it is determined that the changing edge of the open / close state signal is not a change in the state of the relay, the calculation unit adds a first constant (N1) (N1 is a natural number) times the time between zero crossing points to the control start time, then transmits a control signal and determines whether there is a change in the state of the relay, thereby recalculating the control start time.

[0016] Another aspect of the present disclosure is a heating device including a heater and the control device described above. In the heating device according to this aspect, the control device performs temperature control using a relay.

[0017] Yet another aspect of the present disclosure is a control method for controlling a relay, the control method including: generating a zero-cross point waveform indicating a point in time at which the waveform of the AC power supply reaches 0 V based on a waveform of the AC power supply; setting a zero-cross point acquired from the zero-cross point waveform as a reference time point; transmitting a control signal to the relay after a control start time from the reference time point to perform zero-cross control; and transmitting a status signal indicating a status of the relay.

[0018] The zero-cross control includes receiving a status signal after transmitting a control signal and detecting a rising edge or a falling edge of the status signal as a changing edge (detection step); measuring a delay time from transmitting the control signal to detecting the changing edge (timing step); judging whether the changing edge is a state change of the relay based on the delay time (judging step); calculating a control start time from the time between zero-cross points and the delay time when it is judged that the changing edge is a state change of the relay (part of the calculation step); and when it is judged that the changing edge is not a state change of the relay, adding a first constant (N1) (N1 is a natural number) times the time between zero-cross points to the control start time, and then transmitting a control signal and judging whether there is a state change of the relay, thereby recalculating the control start time (part of the calculation step).

[0019] The zero cross point time is the time between two consecutive zero cross points.

[0020] According to the present disclosure, it is possible to provide a control device that performs highly accurate zero-cross control and a control method for the control device. Furthermore, according to the present disclosure, it is possible to provide a heating device with improved heating performance.

[0021] FIG. 1 is a block diagram of an iron using a controller unit according to an embodiment of the present disclosure. FIG. 2 is a circuit diagram of the controller unit according to the embodiment. FIG. 3 is a timing chart illustrating an example of zero-cross control in the controller unit according to the embodiment. FIG. 4 is a flowchart illustrating an example of zero-cross control in the controller unit according to the embodiment. FIG. 5 is a timing chart illustrating generation of a ZVP waveform in the controller unit according to the embodiment. FIG. 6 is a timing chart illustrating relay state detection in the controller unit according to the embodiment. FIG. 7 is a timing chart illustrating an example of relay operation delay time in the controller unit according to the embodiment. FIG. 8 is a timing chart illustrating another example of relay operation delay time in the controller unit according to the embodiment. FIG. 9 is a timing chart illustrating another example of relay operation delay time in the controller unit according to the embodiment. FIG. 10 is a timing chart illustrating another example of zero-cross control in the controller unit according to the embodiment. FIG. 11 is a flowchart illustrating operation of a microcomputer in the controller unit according to the embodiment.

[0022] (Knowledge that forms the basis of the present disclosure) At the time when the present inventors conceived the subject matter of the present disclosure, when designing a heating device, if a manufacturer selected a relay whose operational delay time was within the time between two consecutive zero crossing points of the AC power supply, there was no need to consider the case where Td was equal to or greater than Tz.

[0023] Here, the zero cross point refers to the point at which the waveform of the AC power supply becomes 0 V. The time between two consecutive zero cross points of the AC power supply is called the zero cross point interval time and is represented by Tz. The operation delay time of the relay is represented by Td.

[0024] Recently, the number of suppliers of electronic components, including relays, has increased, primarily overseas, and manufacturers are placing importance on utilizing components with diverse performance and quality in order to continue their business. The inventors of the present application discovered a problem with zero-cross control when the relay's Td is equal to or greater than Tz during the design of a relay control device, and came up with the subject matter of the present disclosure to solve the problem. In this disclosure, zero-cross control refers to control of a relay synchronized with the zero-cross point.

[0025] When the Td of the relay is large, for example, when the maximum operation delay time of the relay exceeds Tz at the product rated value, the control device must correct the operation timing of the relay in order to perform zero-cross control. Hereinafter, this correction will be referred to as zero-cross correction.

[0026] By using a control device with a highly accurate zero-crossing correction function in heating devices such as irons, manufacturers can easily design devices that take into account the lifespan of the heating device and electromagnetic interference noise, without having to redesign each relay to account for variations in relay operating time due to component variations, changes over time, and environmental influences, which were previously difficult to design.

[0027] That is, manufacturers can design heating devices to the extent necessary for the relay Td specifications, thereby improving efficiency. Manufacturers can use low-cost relays in heating devices. Manufacturers can quickly respond to the end of the life cycle of components that make up heating devices, as well as changes in people, machines, materials, and methods.

[0028] Furthermore, manufacturers can configure a highly accurate zero-crossing correction function using software and apply this correction function to a conventional control device, thereby creating a heating device equipped with this correction function without making major changes to the control device hardware.

[0029] The present disclosure provides a control device that performs highly accurate relay control using a zero-cross point waveform even when the Td of the relay exceeds the Tz, a heating device that uses the control device, and a control method for the control device.

[0030] The control device and control method according to the present disclosure can improve the accuracy of relay opening and closing control. The heating device according to the present disclosure can reduce heat generation and noise in the relay due to discharge, and can achieve a longer life by preventing contact welding and poor contact.

[0031] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. However, for example, detailed descriptions of known matters and redundant descriptions of substantially identical configurations may be omitted.

[0032] (Embodiments) Hereinafter, embodiments of the present disclosure will be described using FIGS. 1 to 11. Here, an iron will be described as an example of a heating device. However, the heating device according to the present embodiments is not limited to an iron. Irons include steam irons and steamers that do not have an ironing surface. Irons may also include those that do not have an ironing surface, i.e., irons that use a heater only to generate steam.

[0033] [1-1. Configuration] [1-1-1. Configuration of iron] As will be described later, the iron includes a base having a ironing surface, a heater for heating the base, and a controller unit for adjusting the temperature of the heater. The heater may be used not only to adjust the temperature of the base but also to generate steam.

[0034] The controller unit controls the relay and adjusts the heater temperature. The controller unit's highly accurate zero-cross control reduces heat generation in the relay and extends the relay's ON time. The controller unit's highly accurate zero-cross control also increases the power supplied to the heater.

[0035] Therefore, the maximum temperature or the duration at the specified temperature of the base can be improved. The amount of steam generated can be improved without changing the heater installed in the iron. By replacing the relay installed in the iron with a relay with a lower rating, the cost of the iron can be reduced without changing the power supplied to the heater. These effects are not only applicable to irons, but also to heating devices that use relay control devices.

[0036] 1 is a block diagram showing the configuration of an iron 100 using a controller unit according to this embodiment. The iron 100 includes a controller unit 101, a tank 102, a pump 103, a vaporization chamber 104, a heater 105, a base 106, a switch 107, a jetting portion 108, and a temperature sensor 109. In this embodiment, the controller unit 101 corresponds to a control device.

[0037] The iron 100 has a steam ejection unit 108 disposed on the bottom surface of the housing. When a user holds the handle and operates the steam ejection unit 108 while pointing the steam ejection unit 108 toward the clothes, the iron 100 ejects steam from the steam ejection unit 108.

[0038] Heater 105 heats vaporization chamber 104 and base 106. Pump 103 supplies water stored in tank 102 to vaporization chamber 104. Vaporization chamber 104 generates steam by heating the supplied water with heater 105. Jet portion 108 jets out the steam.

[0039] Temperature sensor 109 detects the temperature of vaporization chamber 104 and the temperature of heater 105. Controller unit 101 receives information from switch 107 and temperature sensor 109 to control heater 105 and pump 103. Although not shown, temperature sensor 109 may be configured to detect the temperature of the application surface of base 106.

[0040] When the power of the iron 100 is turned on, the controller unit 101 starts heating the vaporization chamber 104 and the base 106 with the heater 105. Based on information from the temperature sensor 109, the vaporization chamber 104 is heated to a temperature at which the water supplied to the vaporization chamber 104 is instantly vaporized to generate steam.

[0041] When switch 107 is turned on, controller unit 101 drives pump 103 to supply water from tank 102 to vaporization chamber 104. The water supplied to vaporization chamber 104 is vaporized into steam, and this steam is sprayed from spray unit 108. When switch 107 is turned off, controller unit 101 stops pump 103 to stop the supply of water from tank 102 to vaporization chamber 104.

[0042] The controller unit 101 controls the heater 105 by relay control, which will be described later, to adjust the temperature of the base 106 and the temperature of the vaporization chamber 104. The controller unit 101 controls the pump 103 to supply water from the tank 102 to the vaporization chamber 104, and adjusts the amount of steam sprayed from the spray unit 108.

[0043] The iron 100 may be configured without the tank 102, the pump 103, and the vaporization chamber 104, and without the steam ejection function.

[0044] 2 shows an example of the circuit configuration of the controller unit 101. FIG. 3 is a timing chart showing the zero-cross control by the controller unit 101 in the iron 100.

[0045] 2, the controller unit 101 includes a relay 111, a ZVP waveform generating circuit 112, a relay state detecting circuit 113, an AC power supply 114, and a microcomputer 115. In this embodiment, the ZVP waveform generating circuit 112, the relay state detecting circuit 113, and the microcomputer 115 correspond to a ZVP waveform generating unit, a relay state detecting unit, and a control unit, respectively.

[0046] The relay 111 receives an opening / closing control signal from the microcomputer 115 and turns the heater 105 on or off. In this embodiment, the opening / closing control signal corresponds to the control signal. Although not shown, the relay 111 and the controller unit 101 may be configured separately, and the relay 111 may be controlled by the controller unit 101.

[0047] The ZVP waveform generation circuit 112 generates a zero-cross point waveform, which is a pulse waveform, from the waveform of the AC power input from the AC power supply 114. Hereinafter, the zero-cross point waveform will also be referred to as a zero voltage pulse (ZVP) waveform. The ZVP waveform generation circuit 112 outputs the ZVP waveform to the microcomputer 115.

[0048] The relay state detection circuit 113 detects whether the relay 111 is ON or OFF, and transmits an open / closed state signal to the microcomputer 115. Therefore, as will be described later, the relay state detection circuit 113 receives a relay state signal (relay signal) and a ZVP waveform from the relay 111.

[0049] The relay state detection circuit 113 transmits a relay signal or a ZVP waveform as an open / closed state signal according to the state of the relay 111. In this embodiment, the open / closed state signal corresponds to a state signal.

[0050] As will be described later, the microcomputer 115 detects the power supply frequency from the waveform of the AC power input from the AC power supply 114. The microcomputer 115 detects the zero cross points from the ZVP waveform input from the ZVP waveform generating circuit 112.

[0051] The microcomputer 115 transmits an open / close control signal to the relay 111 and receives an open / close state signal from the relay state detection circuit 113 to turn on or off the heater 105. The microcomputer 115 performs calculations for zero-crossing correction using the ZVP waveform, the open / close control signal, and the open / close state signal.

[0052] As a result, the microcomputer 115 calculates the control start time of the relay 111 as shown in Fig. 3. Hereinafter, the control start time of the relay 111 will be referred to as Ts. The microcomputer 115 sets the falling edge of the ZVP waveform as the reference time point (time point A in Fig. 3), and transmits an open / close control signal that turns on the relay 111 with a delay of Ts from this falling edge.

[0053] When the relay 111 starts to turn on in response to the open / close control signal, the relay 111 is turned on after Td (time B in FIG. 3). In other words, the microcomputer 115 can synchronize the operation of the relay with the rising edge of the ZVP waveform.

[0054] As described above, the microcomputer 115 can synchronize the relay 111 with the zero-cross point and control it with high precision by using the zero-cross control according to this embodiment. As a result, the iron 100 can improve heating performance by controlling the temperature of the heater 105.

[0055] To perform the above operations, the microcomputer 115 includes a detection unit 201 , a timer unit 202 , a determination unit 203 , and a calculation unit 204 .

[0056] As will be described later, the detection unit 201 receives the open / close state signal after transmitting the open / close control signal and detects a changing edge of the open / close state signal. The changing edge of the open / close state signal means a rising edge or a falling edge of the open / close state signal. The timer unit 202 measures the delay time from transmitting the open / close control signal to detecting the changing edge of the open / close state signal.

[0057] The determination unit 203 determines, based on the delay time, whether or not the changing edge of the open / close state signal is a state change of the relay 111. Specifically, the determination unit 203 determines whether or not the changing edge of the open / close state signal is a state change of the relay based on whether or not the delay time is within a predetermined period expressed as a multiple of Tz.

[0058] If it is determined that the changing edge of the open / close state signal is a state change of the relay 111, the calculation unit 204 calculates Ts from Tz and the delay time. If it is determined that the changing edge of the open / close state signal is not a state change of the relay 111, the calculation unit 204 adds a first constant (N1) times Tz (N1 is a natural number) to Ts, and then transmits an open / close control signal and determines whether there is a state change of the relay 111, thereby recalculating Ts.

[0059] [1-2. Operation] The operation of the iron 100 configured as described above will be described with reference to Figs. 3 to 11. Fig. 4 is a flowchart showing an example of zero-cross control of the iron 100 by the controller unit 101. Fig. 5 is a timing chart showing generation of a ZVP waveform by the ZVP waveform generating circuit 112.

[0060] Fig. 6 is a timing chart showing the state detection of the relay 111 by the relay state detection circuit 113. Figs. 7 to 10 are timing charts showing several examples of the operation delay time of the relay 111 in the controller unit 101. Fig. 11 is a flowchart showing another example of zero-cross control in the controller unit 101.

[0061] In step S1, the microcomputer 115 starts zero-cross control in response to a user's operation to start heating of the iron 100.

[0062] In step S2, the ZVP waveform generation circuit 112 generates a ZVP waveform. That is, in the ZVP waveform generation circuit 112, the AC power supply waveform, which is a sine wave, is input to the base terminal of the transistor Q1, and the ZVP waveform, which is a rectangular wave, is output from the collector terminal of the transistor Q1 to the microcomputer 115 (see FIG. 2). The ZVP waveform becomes voltages VE and V1 when the transistor Q1 is ON and OFF, respectively, and is in the opposite phase to the AC power supply waveform (see FIG. 5).

[0063] In step S3, the calculation unit 204 of the microcomputer 115 calculates Tz and the power supply frequency. That is, the microcomputer 115 measures the time between the falling edge (time C in FIG. 5) and the rising edge (time D in FIG. 5) of the waveform input from the ZVP waveform generation circuit 112. This time is Tz.

[0064] Since Tz corresponds to approximately half a cycle of the AC power supply, which is a sine wave, the microcomputer 115 can calculate the frequency of the AC power supply from Tz. For example, Tz is approximately 10 ms for a 50 Hz AC power supply, and Tz is approximately 8.33 ms for a 60 Hz AC power supply.

[0065] However, the power supply frequency shown in this embodiment is merely an example. The Tz and power supply frequency calculated by the microcomputer 115 are not quantitatively definitive. The microcomputer 115 calculates the power supply frequency by calculating Tz, so it can calculate the power supply frequency even when there is frequency variation in the AC power supply or when the power supply frequency is other than 50 Hz or 60 Hz.

[0066] In step S3, the microcomputer 115 initializes Ts by setting it to 0. In step S4, the microcomputer 115 sets Ts_old to Ts. Ts_old is the previous control start time Ts in the operational flowchart, as will be described later, and is set in step S8.

[0067] In step S4, the microcomputer 115 sets the falling edge of the ZVP waveform as the reference time point, and transmits an open / close control signal to turn on the relay 111 after a time Ts has elapsed from this falling edge. For example, if Ts is 0, the microcomputer 115 transmits the open / close control signal to the relay 111 at the time of the falling edge of the ZVP waveform (time point A in FIG. 3).

[0068] The timer 202 of the microcomputer 115 transmits an open / close control signal to the relay 111 in step S4 described above, and simultaneously starts measuring the delay time until the transition edge of the open / close state signal is detected.

[0069] In step S5, the microcomputer 115 waits until it receives an open / close state signal, which is a response signal to the open / close control signal, from the relay state detection circuit 113. Specifically, when an open / close control signal to turn on the relay 111 is transmitted, the microcomputer 115 waits until it receives an open / close state signal indicating that the relay 111 is on. When an open / close control signal to turn off the relay 111 is transmitted, the microcomputer 115 waits until it receives an open / close state signal indicating that the relay 111 is off.

[0070] The operation of relay state detection circuit 113 will be described with reference to Figures 2, 4, and 6. As shown in Figure 2, when the contacts of relay 111 are open and OFF, the waveform of the AC power supply is input to the base terminal of transistor Q2 in relay state detection circuit 113. As a result, relay state detection circuit 113 outputs a ZVP waveform, which is a rectangular wave, from the collector terminal of transistor Q2 to microcomputer 115 as an open / closed state signal (period E in Figure 6).

[0071] In the relay state detection circuit 113, when the contacts of the relay 111 are closed and ON, the AC power waveform is not input to the base terminal of the transistor Q2, and the transistor Q2 does not turn ON. As a result, the relay state detection circuit 113 outputs a predetermined voltage V1 from the collector terminal of the transistor Q2 to the microcomputer 115 as an open / closed state signal (period F in FIG. 6). In other words, the open / closed state signal is a signal output from the collector terminal of the transistor Q2.

[0072] In step S6, the detection unit 201 of the microcomputer 115 detects a change in the open / closed state of the relay 111 by detecting the following changing edge of the open / closed state signal in the ZVP waveform input from the ZVP waveform generation circuit 112 and the open / closed state signal received from the relay state detection circuit 113 (detection step). Detecting a changing edge of the open / closed state signal means detecting that the state of the relay has changed from ON to OFF or from OFF to ON.

[0073] A method for detecting a changing edge of the open / close state signal will now be described. When the relay 111 is OFF (period E in FIG. 6), the open / close state signal exhibits the same waveform as the ZVP waveform, in which voltages V1 and VE alternate every Tz.

[0074] Therefore, when an open / close control signal for turning on the relay 111 is transmitted using the falling edge of the ZVP waveform as the reference time point, the detection unit 201 of the microcomputer 115 can accurately detect the change of the relay 111 from OFF to ON when the open / close state signal has a rising edge (changing edge) at which the voltage VE switches to voltage V1 during the period when the ZVP waveform is voltage VE.

[0075] That is, when an open / close control signal for turning on the relay 111 is transmitted using the falling edge of the ZVP waveform as the reference time point, the microcomputer 115 can accurately detect that the relay 111 has changed from OFF to ON during the first predetermined period. The first predetermined period is the period between the time point when the second constant (N2) times Tz has elapsed from the reference time point and the time when another Tz has elapsed from that time point. Note that N2 is an even natural number.

[0076] That is, the first specified period includes (1) the period between the point when 0 times Tz has passed since the reference point (i.e., the reference point) and the point when another Tz has passed from that point, (2) the period between the point when 2 times Tz has passed since the reference point and the point when another Tz has passed from that point, and (3) the period between the point when 4 times Tz has passed since the reference point and the point when another Tz has passed from that point.

[0077] However, outside the first predetermined period, the microcomputer 115 cannot accurately detect that the relay 111 has changed from OFF to ON. In this case, the microcomputer 115 transmits an open / close control signal for turning on the relay 111 with a delay of Tz from the reference time point.

[0078] As a result, the changing edge of the open / close state signal is delayed by Tz, and it is possible to accurately detect that the relay 111 has changed from OFF to ON during the first predetermined period. This is equivalent to the microcomputer 115 switching the reference time point for transmitting the open / close control signal to the relay 111 from the falling edge to the rising edge of the ZVP waveform.

[0079] As described above, when the open / close state signal has a rising edge (changing edge) during the first predetermined period, the detection unit 201 of the microcomputer 115 can accurately detect that the relay 111 has changed from OFF to ON.

[0080] On the other hand, when the relay 111 is ON (period F in FIG. 6 ), the open / close state signal has voltage V1. Therefore, when an open / close control signal for turning the relay 111 OFF is transmitted using the rising edge of the ZVP waveform as a reference time point, the detection unit 201 of the microcomputer 115 can accurately detect the change of the relay 111 from ON to OFF only when the open / close state signal has a falling edge (changing edge) at which it switches from voltage V1 to voltage VE during the period when the ZVP waveform is voltage V1.

[0081] That is, when the open / close control signal for turning off the relay 111 is transmitted with the rising edge of the ZVP waveform as the reference point, the microcomputer 115 can accurately detect that the relay 111 has changed from ON to OFF during the second predetermined period. The second predetermined period is the period between the point when the second constant (N2) times Tz has elapsed from the reference point and the point when another Tz has elapsed from that point. Note that N2 is an odd natural number.

[0082] That is, the second specified period includes (1) the period between the point when 1 time Tz has passed since the reference point and the point when another Tz has passed from that point, (2) the period between the point when 3 times Tz has passed since the reference point and the point when another Tz has passed from that point, and (3) the period between the point when 5 times Tz has passed since the reference point and the point when another Tz has passed from that point.

[0083] However, outside the second predetermined period, the microcomputer 115 cannot accurately detect that the relay 111 has changed from ON to OFF. In this case, the microcomputer 115 transmits an open / close control signal for turning the relay 111 OFF with a delay of Tz from the reference time point.

[0084] As a result, the changing edge of the open / close state signal is delayed by Tz, and it is possible to accurately detect that the relay 111 has changed from ON to OFF during the second predetermined period. This is equivalent to the microcomputer 115 switching the reference time point for transmitting the open / close control signal to the relay 111 from the rising edge to the falling edge of the ZVP waveform.

[0085] As described above, when the open / close state signal has a falling edge (changing edge) during the second predetermined period, the detection unit 201 of the microcomputer 115 can accurately detect that the relay 111 has changed from ON to OFF.

[0086] That is, the microcomputer 115 can change the period during which a change in the open / close state of the relay 111 can be detected by setting the reference time point for transmitting the open / close control signal to the falling edge of the ZVP waveform or to the rising edge of the ZVP waveform.

[0087] In step S6, the timer 202 of the microcomputer 115 measures the time from when the open / close control signal is sent to the relay 111 until the rising edge of the open / close state signal is detected (time measurement step). Hereinafter, the time measured in this step will be referred to as delay time T. This allows the determination unit 203 of the microcomputer 115 to determine whether the detected changing edge (rising edge of the open / close state signal) is a state change of the relay 111.

[0088] As described above, when the opening / closing control signal is transmitted with the falling edge of the ZVP waveform as the reference time point, the microcomputer 115 can accurately detect that the relay 111 has changed from OFF to ON during the first predetermined period. Therefore, the microcomputer 115 determines whether T is included in the first predetermined period (determination step).

[0089] That is, the determination unit 203 of the microcomputer 115 compares T with Tz, and if T is equal to or greater than 0 and less than Tz, for example, it determines that the changing edge of the open / close state signal is a state change of the relay 111 (Yes in step S6), and proceeds to step S7. Otherwise, the determination unit 203 determines that the changing edge of the open / close state signal is not a state change of the relay 111 (No in step S6), and proceeds to step S8.

[0090] The operation of the controller unit 101 in step S7 will be described below. In step S7, the microcomputer 115 calculates Ts and Td from Tz and T, and calculates Ts when the next opening / closing control signal is to be transmitted (part of the calculation step).

[0091] The calculation unit 204 of the microcomputer 115 sets Td of the relay 111 to T.

[0092] The calculation unit 204 calculates Ts from the following relational expression (1).

[0093] Ts=Tz-Td+Ts_old (1) In steps S3 and S4, Ts_old, which is the previous control start time, is set to an initial value (ie, 0).

[0094] From the above, when Td is smaller than T, the controller unit 101 operates as shown in FIG.

[0095] In step S5, the microcomputer 115 transmits an open / close control signal that changes the relay 111 from OFF to ON (time G in FIG. 7), and then receives an open / close state signal, which is a response signal, from the relay state detection circuit 113.

[0096] In step S6, the detection unit 201 detects a rising edge (time H in FIG. 7). The timer unit 202 of the microcomputer 115 measures T from the transmission of the open / close control signal to the relay 111 to the detection of a changing edge in the open / close state signal. In step S7, the calculation unit 204 of the microcomputer 115 sets Td to T.

[0097] In step S9, if Td is smaller than T, the calculation unit 204 uses Ts of the relay 111 calculated in step S7, as shown in FIG. 3, and transmits an opening / closing control signal to the relay 111 with a delay of Ts from the falling edge of the ZVP waveform (point A in FIG. 3), which is the reference point.

[0098] This allows the controller unit 101 to perform highly accurate open / close control of the relay 111 in synchronization with the zero crossing point (point B in FIG. 3 ). That is, the iron 100 can improve heating performance by controlling the temperature of the heater 105. As shown in FIG. 3 , the microcomputer 115 transmits an open / close control signal to the relay 111 with a delay of Ts from the falling edge of the ZVP waveform, which is the reference point, until the user operates the iron 100 to stop heating.

[0099] In step S10, the microcomputer 115 ends the zero-cross control.

[0100] The operation of the controller unit 101 when the result of step S6 is No will be described.

[0101] When Td is equal to or greater than Tz and smaller than 2Tz, the controller unit 101 operates as shown in Fig. 8. That is, in this case, the open / close state signal has a rising edge in the period from Tz to 2Tz (period J in Fig. 8).

[0102] In step S8, the calculation unit 204 of the microcomputer 115 adds Tz multiplied by a first constant (N1) (N1 is a natural number) to Ts_old and sets the result as a temporary Ts. For example, when N1 is an odd number and N1 is 1, the temporary Ts is the sum of Ts_old and Tz. This is equivalent to the microcomputer 115 switching the reference time point for transmitting the opening / closing control signal to the relay 111 from the falling edge to the rising edge of the ZVP waveform. Note that in steps S3 and S4, Ts_old has already been set to its initial value (i.e., 0). Therefore, the temporary Ts is set to Tz.

[0103] The microcomputer 115 transmits an open / close control signal to turn off the relay 111, and receives an open / close state signal as a response signal to turn the relay from ON to OFF. The microcomputer 115 returns the process to step S4 again (step S4 for the second time).

[0104] The operation of the controller unit 101 in step S4 for the second time will be described using Figure 9. The microcomputer 115 uses the falling edge of the ZVP waveform as the reference time point and transmits an open / close control signal to turn on the relay 111 after a tentative time Ts has elapsed from the reference time point, i.e., after the total time of Tz_old and Tz has elapsed. For example, if Tz_old is 0, the tentative Ts is Tz. The microcomputer 115 transmits the open / close control signal to the relay 111 with a delay of Tz, at the time of the rising edge of the ZVP waveform (time point K in Figure 9).

[0105] Thereafter, in step S5, the microcomputer 115 receives an open / close state signal, which is a response signal to the open / close control signal, from the relay state detection circuit 113.

[0106] In step S6, the detection unit 201 of the microcomputer 115 detects the above-mentioned changing edge (time L in FIG. 9) in the ZVP waveform input from the ZVP waveform generation circuit 112 and the open / close state signal received from the relay state detection circuit 113. The timer unit 202 of the microcomputer 115 measures the delay time T from when the open / close control signal is sent to the relay 111 until the rising edge (changing edge) of the open / close state signal is detected.

[0107] The determination unit 203 of the microcomputer 115 determines whether or not the detected changing edge of the open / close state signal is a state change of the relay 111. When an open / close control signal is transmitted with the rising edge of the ZVP waveform as the reference time point, the determination unit 203 can accurately detect that the relay 111 has changed from OFF to ON during the period between the time point when a second constant (N2) times Tz (N2 is an odd natural number) has elapsed from the reference time point and the time point when Tz has further elapsed from that time point, and therefore determines whether or not T is included in this period.

[0108] The determination unit 203 compares T with Tz, and if T is equal to or greater than Tz but less than 2Tz, for example, it determines that the changing edge of the open / close state signal is a state change of the relay 111 (Yes in step S6), and proceeds to step S7. Otherwise, the determination unit 203 determines that the changing edge of the open / close state signal is not a state change of the relay 111 (No in step S6), and proceeds to step S8.

[0109] The operation of the controller unit 101 in step S7 will be described.

[0110] In step S7, the microcomputer 115 calculates the true Ts and Td from Tz, T and the tentative Ts, and calculates Ts when the next opening / closing control signal is to be transmitted (part of the calculation step).

[0111] The calculation unit 204 of the microcomputer 115 sets Td of the relay 111 to T. In this case, Td is equal to or greater than Tz and smaller than 2Tz.

[0112] The calculation unit 204 calculates the true Ts from the above relational expression (1). In the first step S8 and the second step S4, Ts_old is set to Tz.

[0113] In step S9, when the microcomputer 115 transmits an open / close control signal to the relay 111 to control the temperature of the heater 105, the microcomputer 115 transmits the open / close control signal for turning on the relay 111 with a delay of Ts from the falling edge of the ZVP waveform (point M in FIG. 10), which is the reference point, using Ts of the relay 111 calculated in step S7, as shown in FIG.

[0114] When the relay 111 receives the open / close control signal, the relay 111 is turned on after Td (time O in FIG. 10 ). This allows the controller unit 101 to perform high-precision open / close control of the relay 111 in synchronization with the zero-crossing point. That is, the iron 100 can improve heating performance by controlling the temperature of the heater 105.

[0115] The above description deals with the case where Td is less than 2 Tz. However, the present disclosure is not limited to this, and the controller unit 101 can similarly perform zero-crossing correction even when Td is equal to or greater than Tz. The microcomputer 115 transmits the switching control signal by switching the reference time point from one of the falling edge and rising edge of the ZVP waveform to the other until it detects a changing edge of the switching state signal, and measures Td and determines Ts based on the received switching state signal. This allows the controller unit 101 to perform zero-crossing control for the relay 111 with a long Td.

[0116] That is, the microcomputer 115 adds a first constant (N1) times Tz (N1 is a natural number) to Ts, and then transmits an open / close control signal and determines whether the state of the relay 111 has changed, thereby recalculating the control start time.

[0117] Although the description has been given assuming that N1 is 1, the present disclosure is not limited to this. If N1 is an odd number, the controller unit 101 switches the reference time point for transmitting the opening / closing control signal from one of the rising edge and the falling edge of the zero-crossing point waveform to the other, and recalculates Ts.

[0118] As a result, when the controller unit 101 determines that the detected changing edge of the open / close state signal does not indicate a state change of the relay 111, it changes the reference time point for transmitting the open / close control signal to change the period for detecting a state change of the relay 111. As a result, even if Td of the relay 111 exceeds Tz, it is possible to calculate Ts and perform highly accurate zero-cross control.

[0119] The microcomputer 115 determines whether the changing edge of the open / close state signal is a change in the state of the relay 111 based on whether the delay time T is within a predetermined period expressed as a second constant (N2) multiplied by Tz, where N2 is a natural number.

[0120] This allows the controller unit 101 to calculate Ts and perform highly accurate zero-cross control even when the operation delay time of the relay 111 exceeds Tz.

[0121] The microcomputer 115 may store the calculated true Ts, and when starting the next zero-crossing control, in step S3, read the stored true Ts and set the true Ts as the initial value for Ts.

[0122] As described above, the zero-cross control according to this embodiment enables the controller unit 101 to control the relay with high precision in synchronization with the zero-cross point. As a result, the iron 100 can improve heating performance by controlling the temperature of the heater 105.

[0123] Fig. 11 is a flowchart showing the operation of the microcomputer 115 in the controller unit 101. As shown in Fig. 11, in step S12, the detection unit 201 receives the open / close state signal after transmitting the open / close control signal, and detects a changing edge of the open / close state signal (detection step).

[0124] In step S13, the timer 202 measures the delay time from the transmission of the open / close control signal to the detection of the changing edge of the open / close state signal (time measurement step).

[0125] In step S14, the determination unit 203 determines whether the changing edge of the open / close state signal is a state change of the relay 111 based on the delay time (determination step).

[0126] As a result of step S14, if the judgment unit 203 judges that the changing edge of the open / close state signal is a change in the state of the relay, in step S15, the calculation unit 204 calculates the control start time Ts from the time between zero crossing points Tz and the delay time T (part of the calculation step).

[0127] If the determination unit 203 determines in step S14 that the changing edge of the open / close state signal does not indicate a state change of the relay 111, then in step S16, the calculation unit 204 adds a first constant (N1) (N1 is a natural number) times the time between zero crossing points Tz to the control start time Ts, and then returns the process to step S12. In step S12, the calculation unit 204 transmits the open / close control signal and determines whether there is a state change of the relay 111, and recalculates the control start time Ts (part of the calculation step).

[0128] In this embodiment, the microcomputer 115 starts measurement using the falling edge of the ZVP waveform as the reference time point. However, the present disclosure is not limited to this, and measurement may be started using the rising edge of the ZVP waveform as the reference time point.

[0129] In this embodiment, the microcomputer 115 switches the reference time point from one of the rising edge and the falling edge of the ZVP waveform to the other. The present disclosure is not limited to this, and this operation may be performed at predetermined time intervals or randomly. If N1 is an odd number, the microcomputer 115 can switch the reference time point from one of the rising edge and the falling edge to the other, and if N1 is an even number, the microcomputer 115 can prevent the reference time point from being switched.

[0130] In the zero-crossing control according to this embodiment, the falling edge of the ZVP waveform is used as the reference time point. However, the present disclosure is not limited to this, and the rising edge of the ZVP waveform may also be used as the reference time point. Furthermore, the reference time point may be fixed to either the falling edge or the rising edge of the ZVP waveform, or may be alternately used, or may be randomly combined. This reduces the load on the contacts of the relay 111.

[0131] In the present embodiment, the relay operation, Td, and Ts when the relay 111 is turned on have been described. The same applies to the relay operation, Td, and Ts when the relay 111 is turned off.

[0132] That is, the microcomputer 115 transmits an open / close control signal for turning off the relay 111, using both or either of the falling and rising edges of the ZVP waveform as reference time points, until it detects that the state of the relay 111 has changed from ON to OFF using an edge other than the ZVP waveform.The microcomputer 115 measures Td and determines Ts based on the received open / close state signal.This allows zero-cross control to be performed on relays with long Td when OFF.

[0133] [1-3. Effects, etc.] As described above, one aspect of the present embodiment is a controller unit 101 (control device) that controls a relay. The controller unit 101 according to this aspect includes a ZVP waveform generating circuit 112 (ZVP waveform generating unit), a microcomputer 115 (control unit), and a relay state detecting circuit 113 (relay state detecting unit).

[0134] The ZVP waveform generation circuit 112 generates a zero-cross point waveform from the waveform of the AC power supply. The microcomputer 115 uses the zero-cross point obtained from the zero-cross point waveform as a reference, and transmits an open / close control signal to the relay 111 after a control start time from that reference, thereby performing zero-cross control. The relay state detection circuit 113 detects the state of the relay 111 and transmits an open / close state signal.

[0135] The microcomputer 115 includes a detection unit 201 , a timer unit 202 , a determination unit 203 , and a calculation unit 204 .

[0136] The detection unit 201 receives the open / close state signal after transmitting the open / close control signal and detects the rising edge or falling edge of the open / close state signal as a changing edge. The timing unit 202 measures the delay time from transmitting the open / close control signal to detecting the changing edge. The determination unit 203 determines whether the changing edge of the open / close state signal is a state change of the relay 111 based on the delay time.

[0137] When it is determined that the changing edge of the open / close state signal is a state change of the relay 111, the calculation unit 204 calculates the control start time from the time between zero crossing points and the delay time. The time between zero crossing points is the time between two consecutive zero crossing points.

[0138] When it is determined that the changing edge of the open / close state signal is not a state change of the relay 111, the calculation unit 204 adds a first constant (N1) (N1 is a natural number) times the time between zero crossing points to the control start time, and then transmits the open / close control signal and determines whether there is a state change of the relay 111, thereby recalculating the control start time.

[0139] With this configuration, in the controller unit 101, even if the operation delay time of the relay 111 exceeds the time between zero-crossing points, the determination unit 203 determines whether the changing edge is a state change of the relay based on the delay time, and the calculation unit 204 calculates the control start time. This allows the controller unit 101 to perform highly accurate zero-crossing control.

[0140] In this embodiment, the controller unit 101 may recalculate the control start time by switching the reference time point for transmitting the opening / closing control signal from one of the rising edge and the falling edge of the zero-crossing point waveform to the other, with N1 being an odd number.

[0141] With this configuration, when the controller unit 101 determines that the detected changing edge of the open / close state signal does not represent a state change of the relay 111, it changes the reference time point for transmitting the open / close control signal to change the period for detecting a state change of the relay 111. This makes it possible to calculate the control start time and perform highly accurate zero-cross control even if the operation delay time of the relay 111 exceeds the time between zero-cross points.

[0142] In this aspect, the determination unit 203 may determine whether the changing edge of the open / close state signal is a state change of the relay 111 based on whether the delay time is within a predetermined period expressed as a second constant (N2) times the time between zero crossing points, where N2 is a natural number.

[0143] With this configuration, the controller unit 101 can calculate the control start time and perform highly accurate zero cross control even if the operation delay time of the relay 111 exceeds the time between zero cross points.

[0144] In this aspect, the relay state detection circuit 113 may receive a relay state signal and a zero-cross point waveform from the relay 111, and transmit the relay state signal or the zero-cross point waveform as an open / closed state signal in accordance with the relay state signal.

[0145] This configuration enables highly accurate zero-cross control.

[0146] Another aspect of the present embodiment is a heating device. The heating device according to this aspect is iron 100 including a heater and the above-described controller unit 101. In the heating device according to this aspect, controller unit 101 may perform temperature control using relay 111.

[0147] This configuration allows temperature control to be performed through highly accurate zero-cross control, thereby improving the heating performance of the iron 100.

[0148] Another aspect of the present embodiment is a control method for controlling a relay, the control method comprising: generating a zero-cross point waveform indicating a time point at which the waveform of the AC power supply reaches 0 V, based on the waveform of the AC power supply; using a zero-cross point obtained from the zero-cross point waveform as a reference, transmitting an open / close control signal to the relay 111 after a control start time from the reference to perform zero-cross control; transmitting an open / close state signal indicating the state of the relay 111; receiving the open / close state signal after transmitting the open / close control signal, and detecting a rising edge or a falling edge of the open / close state signal as a changing edge (detection step); measuring a delay time from transmitting the open / close control signal to detecting the changing edge (timing step); determining whether the changing edge is a state change of the relay 111 based on the delay time (determination step); and, when it is determined that the changing edge is a state change of the relay 111, calculating a control start time from the time between zero-cross points and the delay time (part of the calculation step). When it is determined that the changing edge is not a state change of the relay 111, the control start time may be recalculated (part of the calculation step) by adding a first constant (N1) (N1 is a natural number) times the time between zero crossing points to the control start time, and then transmitting an opening / closing control signal and determining whether there is a state change of the relay 111.

[0149] The zero cross point time is the time between two consecutive zero cross points.

[0150] With this control method, even if the operation delay time of the relay 111 exceeds the time between zero-crossing points, the controller unit 101 can determine whether the changing edge is a relay state change based on the delay time and calculate the control start time, thereby enabling the controller unit 101 to perform highly accurate zero-crossing control.

[0151] (Other Embodiments) As described above, the above embodiment has been described as an example of the technology according to the present disclosure. However, the technology according to the present disclosure is not limited to this, and can also be applied to similar embodiments in which the components of the above embodiment are modified, replaced, added, or omitted.

[0152] In the above embodiment, relay control of an iron has been described as an example of zero-cross control. Zero-cross control is effective when using a component that performs an opening and closing operation and generates an operation delay time. Therefore, the zero-cross control according to the present disclosure is not limited to the use of contact relays. It can also be applied to contactless relays (solid-state relays) such as triacs, thyristors, and transistors.

[0153] A processor, for example, may be used as the controller unit according to the present disclosure. In this case, the processor can execute various processes by reading a program from a storage medium storing the program and executing the program. In other words, the process content can be changed by changing the program stored in the storage medium. This increases the degree of freedom in changing the control content of the controller unit.

[0154] The processor is, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit), etc. The storage medium is, for example, a hard disk, a flash memory, or an optical disk, etc.

[0155] The controller unit may be implemented using wired logic, which is not programmable. This is effective in improving processing speed. The wired logic may be, for example, an application specific integrated circuit (ASIC).

[0156] The controller unit may be configured by combining a processor and wired logic, which increases the degree of freedom in software design and improves processing speed.

[0157] The controller unit and a circuit having a function different from that of the controller unit may be configured in a single semiconductor device, such as an analog-to-digital (A / D) conversion circuit or a digital-to-analog (D / A) conversion circuit.

[0158] The controller unit may be configured with one semiconductor element or multiple semiconductor elements, in which case the control according to the present disclosure may be performed by semiconductor elements of different types.

[0159] Any expression relating to the present disclosure converted into at least one of a method, a device, a system, a recording medium, a computer program, etc. is also effective as one aspect of the present disclosure. For example, the present disclosure also includes a program for causing a processor to execute the control device according to the present embodiment.

[0160] (Additional Note) In the present disclosure, the following techniques are disclosed through the description of the above embodiments.

[0161] (Technology 1) Technology 1 is a control device for controlling a relay. The control device according to technology 1 includes a ZVP waveform generating unit, a control unit, and a relay state detecting unit.

[0162] The ZVP waveform generator generates a zero-cross point waveform from the waveform of the AC power supply. The controller uses a zero-cross point acquired from the zero-cross point waveform as a reference and transmits a control signal to a relay after a control start time from the reference to perform zero-cross control. The relay state detector detects the state of the relay and transmits a state signal.

[0163] The control unit includes a detection unit, a timer unit, a determination unit, and a calculation unit.

[0164] The detection unit receives the status signal after transmitting the control signal and detects a rising edge or a falling edge of the status signal as a changing edge. The timer unit measures a delay time from transmitting the control signal to detecting the changing edge. The determination unit determines whether the changing edge is a state change of the relay based on the delay time.

[0165] When the changing edge is determined to be a change in the state of the relay, the calculation unit calculates the control start time from the zero crossing point interval time, which is the time between two consecutive zero crossing points among the zero crossing points, and the delay time.

[0166] When it is determined that the changing edge is not the state change of the relay, the calculation unit adds a first constant (N1) (N1 is a natural number) times the time between zero crossing points to the control start time, and then transmits the control signal and determines the state change of the relay, thereby recalculating the control start time.

[0167] With this configuration, even if the relay operation delay time exceeds the time between zero-crossing points in the control device, the determination unit determines whether the transition edge is a relay state change based on the delay time, and the calculation unit calculates the control start time, thereby enabling the control device to perform highly accurate zero-crossing control.

[0168] (Technology 2) In a control device according to Technology 2, in addition to the configuration according to Technology 1, the control unit sets the first constant (N1) to an odd number, switches the reference time point for transmitting the control signal from one of the rising edge and the falling edge of a zero-crossing point waveform to the other, and recalculates the control start time.

[0169] With this configuration, when the control device determines that the detected changing edge of the open / close state signal does not represent a state change of the relay, it changes the period for detecting a state change of the relay by switching the reference time point for transmitting the control signal. This makes it possible to calculate the control start time and perform highly accurate zero-cross control even if the relay operation delay time exceeds the time between zero-cross points.

[0170] (Technology 3) In a control device according to Technology 3, in addition to the configuration according to Technology 1 or 2, the determination unit determines whether the changing edge is the state change of the relay based on whether the delay time is within a predetermined period expressed as a second constant (N2) times the time between zero crossing points (N2 is a natural number).

[0171] With this configuration, the control device can calculate the control start time and perform highly accurate zero-cross control even if the operation delay time of the relay exceeds the time between zero-cross points.

[0172] (Technology 4) In a control device according to Technology 4, in addition to the configuration according to any one of Technology 1 to Technology 3, the relay state detection unit receives a relay signal and the zero-cross point waveform from the relay, and transmits the relay signal or the zero-cross point waveform as the state signal in accordance with the relay signal.

[0173] This configuration enables highly accurate zero-cross control.

[0174] (Technology 5) Technology 5 is a heating device including a heater and a control device having a configuration according to any one of technologies 1 to 4. In the heating device according to technology 5, the control device controls the temperature of the heater using the relay.

[0175] This configuration allows temperature control to be performed through highly accurate zero-cross control, thereby improving the heating performance of the heating device.

[0176] (Technology 6) Technology 6 is a control method for controlling a relay.

[0177] A control method according to Technology 6 includes: generating a zero-cross point waveform indicating a time point at which the waveform of the AC power supply reaches 0 V, based on the waveform of the AC power supply; using a zero-cross point obtained from the zero-cross point waveform as a reference, transmitting a control signal to a relay after a control start time from the reference; and transmitting a status signal indicating a status of the relay.

[0178] The zero-cross control includes: receiving the state signal after transmitting the control signal, and detecting a rising edge or a falling edge of the state signal as a changing edge (detection step); measuring a delay time from the transmission of the control signal to the detection of the changing edge (timing step); judging whether the changing edge is a state change of the relay based on the delay time (judging step); calculating the control start time from a zero-cross point interval time, which is a time between two consecutive zero-cross points among the zero-cross points, and the delay time, when it is judged that the changing edge is not the state change of the relay (part of the calculation step); and adding a first constant (N1) times the zero-cross point interval time (N1 is a natural number) to the control start time, and then transmitting the control signal and judging the state change of the relay, thereby recalculating the control start time (part of the calculation step).

[0179] According to the control method of Technology 6, even if the relay operation delay time exceeds the time between zero-crossing points, the control device can determine whether the transition edge represents a change in the state of the relay based on the delay time and calculate the control start time. As a result, the control device can perform highly accurate zero-crossing control.

[0180] The present disclosure is applicable to a control device that controls a relay. The present disclosure is also applicable to a heating device that includes the control device and a heat generating unit controlled by the control device. Specifically, the present disclosure is applicable to an iron, a steamer, a dryer, an electric heater, and the like.

[0181] REFERENCE SIGNS LIST 100 Iron (heating device) 101 Controller unit (control device) 102 Tank 103 Pump 104 Vaporization chamber 105 Heater 106 Base 107 Switch 108 Spout section 109 Temperature sensor 111 Relay 112 ZVP waveform generation circuit (ZVP waveform generation section) 113 Relay state detection circuit (relay state detection section) 114 AC power supply 115 Microcomputer (control section) 201 Detection section 202 Time counting section 203 Determination section 204 Calculation section

Claims

1. A control device for controlling a relay, comprising: a ZVP waveform generation unit that generates, based on the waveform of an AC power supply, a zero-cross point waveform that indicates a time point at which the waveform of the AC power supply becomes 0 V; a control unit that uses a zero-cross point obtained from the zero-cross point waveform as a reference and transmits a control signal to the relay after a control start time from the reference, to perform zero-cross control; and a relay state detection unit that transmits a state signal that indicates the state of the relay, wherein the control unit comprises: a detection unit that receives the state signal after transmitting the control signal, and detects a rising edge or a falling edge of the state signal as a changing edge; a timing unit that measures a delay time from the transmission of the control signal to the detection of the changing edge; a determination unit that determines whether the changing edge is a state change of the relay based on the delay time; and a calculation unit, wherein when it is determined that the changing edge is the state change of the relay, the calculation unit calculates the control start time from the zero-cross point interval time that is the time between two consecutive zero-cross points of the zero-cross points, and the delay time, When it is determined that the changing edge is not the state change of the relay, the control device adds a first constant multiple (the first constant is a natural number) of the time between zero crossing points to the control start time, and then transmits the control signal and determines the state change of the relay, thereby recalculating the control start time.

2. The control device according to claim 1, wherein the control unit recalculates the control start time by switching the reference time point for transmitting the control signal from one of the rising edge and the falling edge of the zero-crossing point waveform to the other, with the first constant set to an odd number.

3. The control device according to claim 1 or 2, wherein the judgment unit judges whether the changing edge is the state change of the relay by whether the delay time is within a predetermined period expressed as a second constant multiple of the time between zero crossing points (the second constant is a natural number).

4. A control device as described in claim 1 or 2, wherein the relay state detection unit receives a relay signal and the zero cross point waveform from the relay, and transmits the relay signal or the zero cross point waveform as the state signal in response to the relay signal.

5. A heating device comprising a heater and the control device according to claim 1 or 2, wherein the control device controls the temperature of the heater using the relay.

6. A control method for controlling a relay, comprising: generating a zero-cross point waveform indicating a time point at which the waveform of the AC power supply becomes 0 V based on the waveform of the AC power supply; using a zero-cross point obtained from the zero-cross point waveform as a reference, transmitting a control signal to the relay after a control start time from the reference to perform zero-cross control; and transmitting a status signal indicating a status of the relay, wherein the zero-cross control includes: receiving the status signal after transmitting the control signal, and detecting a rising edge or a falling edge of the status signal as a changing edge; measuring a delay time from the transmission of the control signal to the detection of the changing edge; determining whether the changing edge is a state change of the relay based on the delay time; and when it is determined that the changing edge is the state change of the relay, calculating the control start time from the zero-cross point interval time, which is the time between two consecutive zero-cross points, and the delay time. when it is determined that the changing edge is not the state change of the relay, adding a first constant multiple (the first constant is a natural number) of the time between zero crossing points to the control start time, and then transmitting the control signal and determining the state change of the relay, thereby recalculating the control start time.

Images