Solid State Relay Device and Temperature Control System

Abstract

To provide a solid-state relay device and a temperature adjustment system that can reduce cable cost and wiring cost between a temperature adjustment device and the solid-state relay device, can improve the degree of freedom of the arrangement of the solid-state relay device, and can increase the number of solid-state relay devices that can be controlled by one temperature adjustment device.SOLUTION: A solid-state relay device 2 comprises: a semiconductor switch element SW1 that is connected with both ends of a series circuit of an AC power source 10 and a heater 11 and opens and closes a current path between the AC power source 10 and the heater 11; a control unit 5 that has a radio transmitter-receiver circuit 51 for receiving a radio control signal from a temperature adjustment device 3, and a control circuit 52 for controlling the semiconductor switch element SW1 based on the radio control signal received by the radio transmitter-receiver circuit 51; and a power source unit 6 that generates a DC driving voltage Vout for driving the control unit 5 based on an output voltage of the series circuit of the AC power source 10 and the heater 11, and supplies the generated voltage to the control unit 5.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a solid-state relay device and a temperature control system.

Background Art

[0002] Patent Document 1 discloses a temperature control system. The temperature control system of Patent Document 1 includes a solid-state relay device and a temperature control device. The solid-state relay device is disposed between a heater and a power supply unit, and adjusts the amount of power supplied from the power supply unit to the heater according to a temperature control signal. The temperature control device monitors the temperature of the heater and outputs a temperature control signal to set the temperature of the heater to a target temperature based on the monitoring result.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The input of the solid-state relay device described in Patent Document 1 is connected by wiring to the output of the temperature control device, and a voltage is input from the temperature control device to the solid-state relay device. The temperature control device is often installed inside the control panel. The heater connected to the solid-state relay device is installed near the object to be heated by the heater. When the control panel is far from the object to be heated, the cable between the solid-state relay device and the heater or the cable between the solid-state relay device and the temperature control device or both must be lengthened. This incurs cable costs and wiring costs. When driving a plurality of solid-state relays with one temperature control device, the input of the solid-state relay device (output of the temperature control device) is used by passing and wiring. However, there is a limit to the output current capacity of the output of one temperature control device. Therefore, there is a limit to the number of solid-state relay devices that can be controlled by one temperature control device.

[0005] The present disclosure provides a solid-state relay device and a temperature control system that can reduce the cable cost and wiring cost between the temperature control device and the solid-state relay device, improve the degree of freedom in arranging the solid-state relay device, and further increase the number of solid-state relay devices that can be controlled by one temperature control device.

Means for Solving the Problems

[0006] A solid-state relay device according to an aspect of the present disclosure includes a semiconductor switch element, a control unit, and a power supply unit. The semiconductor switch element is connected to both ends of a series circuit of an AC power supply and a heater to open and close a current path between the AC power supply and the heater. The control unit has a wireless reception circuit that receives a wireless control signal from a temperature control device, and a control circuit that controls the semiconductor switch element based on the wireless control signal received by the wireless reception circuit. The power supply unit generates a DC drive voltage for driving the control unit based on the output voltage of the series circuit of the AC power supply and the heater, and supplies the DC drive voltage to the control unit.

[0007] The temperature control system according to one aspect of the present disclosure includes the above-mentioned solid-state relay device and further includes the above-mentioned temperature control device.

Advantages of the Invention

[0008] According to an aspect of the present disclosure, the cable cost and wiring cost between the temperature control device and the solid-state relay device can be reduced, the degree of freedom in arranging the solid-state relay device can be improved, and furthermore, the number of solid-state relay devices that can be controlled by one temperature control device can be increased.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Mode for Carrying Out the Invention

[0010] [1. Embodiment] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings.

[0011] [1.1 Embodiment 1] [1.1.1 Configuration] FIG. 1 is a block diagram showing a configuration example of a temperature control system 1 including a solid state relay device (SSR device) 2 according to Embodiment 1. The temperature control system 1 in FIG. 1 is used to adjust the temperature of an object to be heated by a heater 11. The temperature control system 1 includes a solid state relay device 2 and a temperature control device 3. As shown in FIG. 1, the solid state relay device 2 is connected in series to an AC power supply 10 and a heater 11. The AC power supply 10 is, for example, a commercial AC power supply. The heater 11 is, for example, an electric resistance heater. While the solid state relay device 2 is on, the current path between the AC power supply 10 and the heater 11 is closed and power is supplied from the AC power supply 10 to the heater 11. While the solid state relay device 2 is off, the current path between the AC power supply 10 and the heater 11 is opened and power is not supplied from the AC power supply 10 to the heater 11. Also, a power switch 12 is connected to the series circuit of the AC power supply 10 and the heater 11.

[0012] FIG. 2 is a block diagram showing a configuration example of the temperature control device 3 in FIG. 1. The temperature control device 3 is connected to a temperature sensor 13. The temperature sensor 13 detects the current temperature of the object to be heated and outputs a temperature signal indicating the current temperature of the object to be heated to the temperature control device 3. The temperature control device 3 controls the temperature of the object to be heated by outputting control information to the solid state relay device 2 based on the current temperature of the object to be heated indicated by the temperature signal from the temperature sensor 13 and controlling the solid state relay device 2.

[0013] The temperature control device 3 in FIG. 2 includes an input / output device 31, a wireless transceiver circuit 32, and a processing circuit 33.

[0014] The input / output device 31 includes a plurality of buttons and a display. The input / output device 31 is used, for example, for inputting the target temperature of the object to be heated and displaying the current temperature of the object to be heated.

[0015] The wireless transceiver circuit 32 functions as a wireless transmission circuit that transmits a wireless control signal to the solid state relay device 2 and a wireless reception circuit that receives a wireless signal from the solid state relay device 2. The wireless transceiver circuit 32 is connected to an antenna 32A. The wireless transceiver circuit 32 transmits a wireless control signal to the solid state relay device 2 through the antenna 32A. The wireless transceiver circuit 32 receives a wireless signal from the solid state relay device 2 through the antenna 32A. The wireless transceiver circuit 32 outputs the received wireless signal to the processing circuit 33.

[0016] The processing circuit 33 executes temperature adjustment processing. The temperature adjustment processing is a process of controlling the wireless transmission / reception circuit 32 so that the wireless transmission / reception circuit 32 transmits a wireless control signal based on the current temperature of the object to be heated indicated by the temperature signal from the temperature sensor 13 and the target temperature of the object to be heated input by the input / output device 31. The wireless control signal indicates control information regarding the solid-state relay device 2. The control information is an output on command for closing the current path between the AC power supply 10 and the heater 11, or an output off command for opening the current path between the AC power supply 10 and the heater 11. The wireless control signal indicating the output on command is referred to as an output on signal, and the wireless control signal indicating the output off command is referred to as an output off signal. The processing circuit 33 is configured to include, for example, a microcontroller having a processor, a memory, a timer, and the like.

[0017] FIG. 3 is a circuit diagram showing a configuration example of the solid-state relay device 2 in FIG. 1. The solid-state relay device 2 includes a semiconductor switch element SW1, a control unit 5, and a power supply unit 6. The semiconductor switch element SW1 is connected to both ends of the series circuit of the AC power supply 10 and the heater 11 to open and close the current path between the AC power supply 10 and the heater 11. The control unit 5 has a wireless transmission / reception circuit 51 and a control circuit 52. The wireless transmission / reception circuit 51 receives a wireless control signal from the temperature adjustment device 3. The control circuit 52 controls the semiconductor switch element SW1 based on the wireless control signal received by the wireless transmission / reception circuit 51. The power supply unit 6 generates a DC drive voltage Vout for driving the control unit 5 based on the output voltage of the series circuit of the AC power supply 10 and the heater 11 and supplies it to the control unit 5.

[0018] The solid-state relay device 2 receives a wireless control signal from the temperature control device 3 by means of the wireless transceiver circuit 51. That is, by providing a communication circuit in the solid-state relay device 2, the control information from the temperature control device 3 to the solid-state relay device 2 is transmitted as a wireless signal. The solid-state relay device 2 controls the semiconductor switch element SW1 to be turned on or off by the control circuit 52 according to the wireless control signal received by the wireless transceiver circuit 51. In this way, in the solid-state relay device 2, the communication between the temperature control device 3 and the solid-state relay device 2 is wireless. Therefore, a cable for communication between the temperature control device 3 and the solid-state relay device 2 is unnecessary. The solid-state relay device 2 generates a DC drive voltage Vout for driving the control unit 5 having the wireless transceiver circuit 51 and the control circuit 52 by the power supply unit 6 based on the output voltage of the series circuit of the AC power supply 10 and the heater 11. Therefore, it is not necessary to supply power from the temperature control device 3 to the solid-state relay device 2, and a power supply cable between the temperature control device 3 and the solid-state relay device 2 is unnecessary. Accordingly, the cable cost and wiring cost between the temperature control device 3 and the solid-state relay device 2 can be reduced. Furthermore, the degree of freedom in arranging the solid-state relay device 2 can be improved. Thereby, the solid-state relay device 2 can be arranged near the heater 11 to shorten the wiring between the solid-state relay device 2 and the heater 11. Therefore, the power loss in the wiring between the solid-state relay device 2 and the heater 11 can be suppressed. Also, the cable cost and wiring cost between the heater 11 and the solid-state relay device 2 can be reduced. Furthermore, since it is not necessary to supply power from the temperature control device 3 to the solid-state relay device 2, even when a plurality of solid-state relay devices 2 are controlled by one temperature control device 3, it is not restricted by the output current capacity of the temperature control device 3. Thus, the number of solid-state relay devices 2 that can be controlled by one temperature control device can be increased.

[0019] Hereinafter, the solid state relay device 2 of FIG. 1 will be described in more detail. As shown in FIG. 3, the solid state relay device 2 includes a switch unit 4, a control unit 5, and a power supply unit 6.

[0020] The switch unit 4 is used to control the supply of power from the AC power supply 10 to the heater 11. The switch unit 4 in FIG. 3 includes a semiconductor switch element SW1, a trigger circuit 41, a zero-cross circuit 42, and a photocoupler PC1. The semiconductor switch element SW1 is connected to both ends of the series circuit of the AC power supply 10 and the heater 11 to open and close the current path between the AC power supply 10 and the heater 11. In FIG. 3, the semiconductor switch element SW1 is connected to both ends of the series circuit of the AC power supply 10 and the heater 11 via the output terminals T1, T2. The semiconductor switch element SW1 is, for example, a triac. A series circuit of a resistor R2 and a capacitor C2 is connected in parallel to the semiconductor switch element SW1. The series circuit of the resistor R2 and the capacitor C2 constitutes a snubber circuit. The trigger circuit 41 controls the trigger signal of the semiconductor switch element SW1. The zero-cross circuit 42 sets the timing at which the trigger circuit 41 outputs the trigger signal to the semiconductor switch element SW1 so that the semiconductor switch element SW1 turns on near the zero phase of the AC voltage of the AC power supply 10. The phototriac PT1 of the photocoupler PC1 is connected to the zero-cross circuit 42 via a resistor R3. When the phototriac PT1 is in the on state, the trigger circuit 41 outputs a trigger signal to the semiconductor switch element SW1 to turn on the semiconductor switch element SW1. The emission and non-emission of the light emitting diode PD1 of the photocoupler PC1 are switched by the control unit 5. Note that the configuration of the switch unit 4 may be a conventionally well-known configuration, so a detailed description of the switch unit 4 is omitted.

[0021] The power supply unit 6 generates a DC drive voltage Vout for driving the control unit 5 based on the output voltage of the series circuit of the AC power supply 10 and the heater 11 and supplies it to the control unit 5. The power supply unit 6 in FIG. 3 includes an AC / DC converter 61, a DC / DC converter 62, and a capacitor C1.

[0022] The AC / DC converter 61 converts the output voltage of the series circuit of the AC power supply 10 and the heater 11 into a predetermined DC voltage Vd (see Fig. 4) and outputs it. As shown in Fig. 3, the AC / DC converter 61 includes a switching power supply circuit 611, a transformer 612, and a rectifier circuit 613. The switching power supply circuit 611 is configured to include, for example, a diode bridge, a smoothing capacitor, a switching circuit, and a microcontroller that controls the switching circuit. The diode bridge is connected to both ends of the series circuit of the AC power supply 10 and the heater 11 via output terminals T1 and T2. The diode bridge rectifies the output voltage of the series circuit of the AC power supply 10 and the heater 11 and outputs the rectified voltage to the smoothing capacitor. The smoothing capacitor smoothes the voltage from the diode bridge and outputs the smoothed voltage to the switching circuit. The switching circuit is configured to include, for example, a switching element. The microcontroller operates according to the output voltage of the series circuit of the AC power supply 10 and the heater 11, and outputs a PWM signal to the switching element of the switching circuit, thereby switching the voltage from the smoothing circuit and applying a pulse voltage to the primary winding of the transformer 612. The secondary winding of the transformer 612 outputs a pulse voltage lower than the pulse voltage input to the primary winding of the transformer 612 to the rectifier circuit 613. The rectifier circuit 613 is configured to include, for example, a rectifier diode. The rectifier circuit 613 rectifies the pulse voltage from the secondary winding of the transformer 612 and outputs the DC voltage Vd.

[0023] The DC / DC converter 62 converts the input voltage Vin into a DC drive voltage Vout and outputs it to the control unit 5. The DC / DC converter 62 converts the input voltage Vin into the DC drive voltage Vout by stepping down the input voltage Vin. The DC / DC converter 62 is, for example, a series regulator. The input voltage Vin is the predetermined DC voltage Vd output from the AC / DC converter 61 or the charging voltage Vc of the capacitor C1. Whether the input voltage Vin becomes the predetermined DC voltage Vd or the charging voltage Vc is determined by whether the semiconductor switch element SW1 is on or off.

[0024] While the semiconductor switch element SW1 is off, the voltage between the output terminals T1 and T2 is approximately equal to the output voltage of the series circuit of the AC power supply 10 and the heater 11. Therefore, the AC / DC converter 61 can output a predetermined DC voltage Vd. On the other hand, while the semiconductor switch element SW1 is on, the peak value of the voltage between the output terminals T1 and T2 drops to about the residual voltage of the semiconductor switch element SW1. The voltage between the output terminals T1 and T2 becomes, for example, an AC rectangular wave voltage with a peak value of about 1V. Therefore, the AC / DC converter 61 cannot generate and output a predetermined DC voltage Vd of a magnitude necessary for the DC / DC converter 62 to generate the DC drive voltage Vout. That is, while the semiconductor switch element SW1 is on, the voltage value of the predetermined DC voltage Vd becomes insufficient for the DC / DC converter 62 to generate the DC drive voltage Vout.

[0025] The capacitor C1 is charged with a predetermined DC voltage Vd while the semiconductor switch element SW1 is off so that the DC / DC converter 62 can output the DC drive voltage Vout even while the semiconductor switch element SW1 is on. The capacitor C1 is connected between the AC / DC converter 61 and the DC / DC converter 62 via the resistor R1, and a diode D1 for a reverse current element is connected between the AC / DC converter 61 and the resistor R1. Thus, when the DC / DC converter 62 cannot obtain a predetermined DC voltage Vd from the AC / DC converter 61, it converts the charging voltage Vc of the capacitor C1 (see FIG. 5) into the DC drive voltage Vout and outputs it to the control unit 5. The capacitor C1 is, for example, an electric double layer capacitor. The capacitance of the capacitor C1 is set in consideration of the consumption current etc. when the solid-state relay device 2 is on so that the voltage value of the DC drive voltage Vout output from the DC / DC converter 62 does not decrease during the normally assumed on-control time of the semiconductor switch element SW1. For example, the voltage value of the predetermined DC voltage Vd is 5.5V, the voltage value of the DC drive voltage Vout is 3.3V, the consumption current is 10 mA, the capacitance of the capacitor C1 is 1F, and the resistance value of the resistor R1 is 47Ω.

[0026] Since the power supply unit 6 includes the capacitor C1, even when the semiconductor switch element SW1 is turned on and the predetermined DC voltage Vd is not output from the AC / DC converter 61, the DC / DC converter 62 can convert the charging voltage V of the capacitor C1 into the DC drive voltage Vout and supply it to the control unit 5. Next, the operation of the power supply unit 6 will be described with reference to FIGS. 4 and 5.

[0027] FIG. 4 is a block diagram showing an example of the operation of the power supply unit 6 while the semiconductor switch element SW1 is off. The AC / DC converter 61 converts the output voltage of the series circuit of the AC power supply 10 and the heater 11 into a predetermined DC voltage Vd. The predetermined DC voltage Vd is input to the DC / DC converter 62 and the capacitor C1. The DC / DC converter 62 receives the predetermined DC voltage Vd as the input voltage Vin, converts the predetermined DC voltage Vd into the DC drive voltage Vout, and outputs it. The capacitor C1 is charged with the predetermined DC voltage Vd.

[0028] FIG. 5 is a block diagram showing an example of the operation of the power supply unit 6 while the semiconductor switch element SW1 is on. While the semiconductor switch element SW1 is on, the AC / DC converter 61 cannot convert the output voltage of the series circuit of the AC power supply 10 and the heater 11 into a predetermined DC voltage Vd. However, the charging voltage Vc of the capacitor C1 charged while the semiconductor switch element SW1 is off is input to the DC / DC converter 62. The DC / DC converter 62 receives the charging voltage Vc of the capacitor C1 as the input voltage Vin, converts the charging voltage Vc of the capacitor C1 into the DC drive voltage Vout, and outputs it.

[0029] Thus, the DC / DC converter 62 converts the predetermined DC voltage Vd output from the AC / DC converter 61 into the DC drive voltage Vout during the period when the semiconductor switch element SW1 is off. The DC / DC converter 62 converts the charging voltage Vc of the capacitor C1 into the DC drive voltage Vout during the period when the semiconductor switch element SW1 is on.

[0030] As described above, the solid state relay device 2 includes a power supply unit 6 for generating a DC drive voltage Vout for driving the control unit 5. During the OFF period of the semiconductor switch element SW1, the power supply unit 6 converts the output voltage of the series circuit of the AC power supply 10 and the heater 11 into the DC drive voltage Vout and supplies it to the control unit 5. During the ON period of the semiconductor switch element SW1, the peak value of the voltage between the output terminals T1 and T2 becomes about 1 V, and the AC / DC converter 61 cannot convert it into a predetermined DC voltage Vd. The power supply unit 6 includes a capacitor C1 charged with a predetermined DC voltage Vd output from the AC / DC converter 61. During the OFF period of the semiconductor switch element SW1, the DC / DC converter 62 converts the charging voltage Vc of the capacitor C1 into the DC drive voltage Vout. Therefore, regardless of whether the semiconductor switch element SW1 is ON or OFF, the power supply unit 6 can supply the DC drive voltage Vout to the control unit 5.

[0031] The control unit 5 operates by the DC drive voltage Vout from the power supply unit 6 and controls the switch unit 4. The control unit 5 in FIG. 3 includes a wireless transceiver circuit 51, a control circuit 52, a voltage drop detection circuit 53, and a switch SW2.

[0032] The switch SW2 is used to switch the ON / OFF of the semiconductor switch element SW1. The switch SW2 is, for example, a transistor. The switch SW2 is connected to the light emitting diode PD1 of the photocoupler PC1. In FIG. 3, the DC drive voltage Vout is input to the series circuit of the light emitting diode PD1 of the photocoupler PC1, the switch SW2, and the resistor R4. When the switch SW2 is turned ON, current flows through the light emitting diode PD1 of the photocoupler PC1 and emits light, and the phototriac PT1 of the photocoupler PC1 is turned ON. As a result, the trigger circuit 41 of the switch unit 4 outputs a trigger signal to the semiconductor switch element SW1, and the semiconductor switch element SW1 is turned ON.

[0033] The wireless transceiver circuit 51 functions as a wireless receiving circuit that receives a wireless control signal from the temperature control device 3 and a wireless transmitting circuit that transmits a wireless signal to the temperature control device 3. The wireless transceiver circuit 51 is connected to the antenna 51A. The wireless transceiver circuit 51 receives a wireless control signal from the temperature control device 3 through the antenna 51A. The wireless transceiver circuit 51 outputs the received wireless control signal to the control circuit 52. The wireless transceiver circuit 51 transmits a wireless signal to the temperature control device 3 through the antenna 51A.

[0034] When the voltage value of the input voltage Vin of the DC / DC converter 62 becomes equal to or lower than a predetermined threshold voltage value, the voltage drop detection circuit 53 outputs a voltage drop signal to the control circuit 52. The predetermined threshold voltage value is set based on the voltage value required for the DC / DC converter 62 to generate the DC drive voltage Vout. For example, when the voltage value of the DC drive voltage Vout is 3.3V, the voltage value required for the DC / DC converter 62 to generate the DC drive voltage Vout is 3.5V. In this case, the predetermined threshold voltage value may be set to 3.6V. This is to enable the control circuit 52 to cope with a decrease in the voltage value of the input voltage Vin of the DC / DC converter 62 before the DC / DC converter 62 actually becomes unable to generate the DC drive voltage Vout. The voltage value of the input voltage Vin of the DC / DC converter 62 decreases when the power supply from the AC power supply 10 stops or when the discharge of the capacitor C1 continues due to the turning on of the semiconductor switch element SW1 and the charging voltage Vc significantly decreases. The voltage drop detection circuit 53 is a power fail down (PFD) circuit for detecting a decrease in the power for driving the control unit 5. The voltage drop detection circuit 53 is configured to include, for example, a voltage detection circuit and a comparator. The voltage detection circuit detects the voltage value of the input voltage Vin of the DC / DC converter 62 and inputs a detection signal indicating the detected voltage value of the input voltage Vin to the comparator. The comparator compares the voltage value of the input voltage Vin indicated by the input detection signal with a predetermined threshold voltage value and outputs a voltage drop signal to the control circuit 52 when the voltage value of the input voltage Vin becomes equal to or lower than the predetermined threshold voltage value.

[0035] The control circuit 52 controls the semiconductor switch element SW1. The control circuit 52 outputs a trigger signal S1 to the switch SW2 in order to control the semiconductor switch element SW1. The control circuit 52 sets the trigger signal S1 output to the switch SW2 to the H level (high level). When the trigger signal S1 is at the H level, the switch SW2 turns on, current flows through the light-emitting diode PD1 of the photocoupler PC1 and emits light, and the phototriac PT1 of the photocoupler PC1 turns on. As a result, the trigger circuit 41 outputs a trigger signal. Therefore, the semiconductor switch element SW1 is controlled to turn on. The control circuit 52 sets the trigger signal S1 output to the switch SW2 to the L level (low level). When the trigger signal S1 is at the L level, the switch SW2 turns off and the light-emitting diode PD1 stops emitting light, and the phototriac PT1 of the photocoupler PC1 turns off. As a result, the trigger circuit 41 stops outputting the trigger signal. Therefore, the semiconductor switch element SW1 is controlled to turn off. The control circuit 52 is configured to include, for example, a microcontroller having a processor, a memory, a timer, etc.

[0036] FIG. 6 is a flowchart showing an example of the operation of the control circuit 52 of the solid-state relay device 2.

[0037] After the control circuit 52 starts operating with the DC drive voltage Vout supplied from the power supply unit 6, until a predetermined charging time elapses, it sets the trigger signal S1 to the L level (S11). As a result, the semiconductor switch element SW1 is controlled to turn off. The predetermined charging time is set to be longer than the time it takes for the charging voltage Vc of the capacitor C1 to reach or exceed the voltage required for the DC / DC converter 62 to generate the DC drive voltage Vout. The predetermined charging time is, for example, 200 seconds. Immediately after the power switch 12 is turned on and the output voltage of the series circuit of the AC power supply 10 and the heater 11 is input to the solid-state relay device 2, since the capacitor C1 is not fully charged, the charging voltage Vc of the capacitor C1 has not reached the voltage value required for the DC / DC converter 62 to generate the DC drive voltage Vout. In this state, if the control circuit 52 controls the semiconductor switch element SW1 to turn on in response to the wireless control signal received by the wireless transceiver circuit 51, the DC drive voltage Vout may not be obtained from the power supply unit 6, and the control unit 5 may not be able to operate. After the control circuit 52 starts operating with the DC drive voltage Vout supplied from the power supply unit 6, until a predetermined charging time elapses, by controlling the semiconductor switch element SW1 to turn off, it ensures that the DC drive voltage Vout can be obtained from the power supply unit 6 even when the semiconductor switch element SW1 is controlled to turn on. That is, after the power switch 12 is turned on, until the capacitor C1 inside the solid-state relay device 2 can be charged to a level where there is no problem with the operation of the solid-state relay device 2, the control circuit 52 does not set the trigger signal S1 to the L level.

[0038] After step S11, when the wireless transceiver circuit 51 receives an output on signal (YES in S12), the control circuit 52 sets the trigger signal S1 to the H level (S13). As a result, the semiconductor switch element SW1 is controlled to turn on.

[0039] After step S11, when the wireless transceiver circuit 51 receives an output off signal (YES in S14), the control circuit 52 sets the trigger signal S1 to the L level (S15). As a result, the semiconductor switch element SW1 is controlled to turn off.

[0040] After step S11, when the voltage drop detection circuit 53 receives a voltage drop signal (YES in S16), the control circuit 52 sets the trigger signal S1 to the L level (S17). As a result, the semiconductor switch element SW1 is controlled to turn off. Since the output of a voltage drop signal from the voltage drop detection circuit 53 means that the power of the AC power supply 10 is decreasing, the control circuit 52 executes a process of controlling the semiconductor switch element SW1 to turn off for safety. After receiving the voltage drop signal from the voltage drop detection circuit 53, the control circuit 52 controls the semiconductor switch element SW1 to turn off regardless of the wireless control signal received by the wireless transceiver circuit 51. The control circuit 52 may ignore the voltage drop signal from the voltage drop detection circuit 53 until a predetermined charging time elapses.

[0041] Next, an example of the operation of the control circuit 52 will be briefly described with reference to FIG. 7. FIG. 7 is a timing chart for explaining an example of the operation of the control circuit 52.

[0042] At time t11, when the temperature control device 3 transmits an output on signal, the wireless transceiver circuit 51 receives this output on signal, and the control circuit 52 sets the trigger signal S1 to the H level. As a result, the semiconductor switch element SW1 is controlled to turn on. At time t12, when the temperature control device 3 transmits an output off signal, the wireless transceiver circuit 51 receives this output off signal, and the control circuit 52 sets the trigger signal S1 to the L level. As a result, the semiconductor switch element SW1 is controlled to turn off.

[0043] At time t13, when the temperature control device 3 transmits an output on signal, the wireless transceiver circuit 51 receives this output on signal, and the control circuit 52 sets the trigger signal S1 to the H level. At time t14, when the temperature control device 3 transmits an output on signal, the wireless transceiver circuit 51 receives this output on signal. However, since the control circuit 52 has already set the trigger signal S1 to the H level, the output on signal at time t14 is ignored. At time t15, when the temperature control device 3 transmits an output off signal, the wireless transceiver circuit 51 receives this output off signal, and the control circuit 52 sets the trigger signal S1 to the L level.

[0044] At time t16, when the temperature control device 3 transmits an output on signal, the wireless transceiver circuit 51 receives this output on signal, and the control circuit 52 sets the trigger signal S1 to the H level. At time t17, the voltage drop detection circuit 53 outputs a voltage drop signal to the control circuit 52. When the control circuit 52 receives the voltage drop signal, it sets the trigger signal S1 to the L level. As a result, the semiconductor switch element SW1 is controlled to turn off.

[0045] Note that when the wireless transceiver circuit 51 receives a wireless control signal from the temperature control device 3, the control circuit 52 may control the wireless transceiver circuit 51 so that the wireless transceiver circuit 51 transmits a wireless signal corresponding to the ACK signal to the temperature control device 3. Thereby, the temperature control device 3 can confirm that the transmission of the wireless control signal from the temperature control device 3 to the solid state relay device 2 has been correctly performed.

[0046] [1.1.2 Operation] Next, an example of the operation of the solid state relay device 2 will be briefly described with reference to FIG. 8. FIG. 8 is a timing chart for explaining an example of the operation of the solid state relay device 2.

[0047] At time t21, the power switch 12 is turned on, and the supply of power from the AC power supply 10 is started. In the solid-state relay device 2, the AC / DC converter 61 of the power supply unit 6 converts the output voltage of the series circuit of the AC power supply 10 and the heater 11 into a predetermined DC voltage Vd and outputs it to the capacitor C1 and the DC / DC converter 62. As a result, the capacitor C1 is charged, and the charging voltage Vc of the capacitor C1 rises. The voltage value of the input voltage Vin of the DC / DC converter 62 is equal to the voltage value V1 of the predetermined DC voltage Vd. The DC / DC converter 62 converts the predetermined DC voltage Vd as the input voltage Vin into a DC drive voltage Vout and outputs it to the control unit 5. In the control unit 5, the control circuit 52 starts operating by the supply of the series drive voltage Vout, and sets the trigger signal S1 to the L level until a predetermined charging time elapses. For example, until time t22, the control circuit 52 sets the trigger signal S1 to the L level.

[0048] At time t22, the temperature control device 3 transmits an output on signal to the solid-state relay device 2. In the solid-state relay device 2, the wireless transceiver circuit 51 receives the output on signal, and thereby the control circuit 52 sets the trigger signal S1 to the H level and controls the semiconductor switch element SW1 to turn on. As a result, the output voltage of the series circuit of the AC power supply 10 and the heater 11 cannot be obtained, so the AC / DC converter 61 cannot output the predetermined DC voltage Vd. However, the charging voltage Vc of the capacitor C1 is input to the DC / DC converter 62, and the capacitor C1 discharges. As a result, the DC / DC converter 62 converts the charging voltage Vc of the capacitor C1 as the input voltage Vin into a DC drive voltage Vout and supplies it to the control unit 5. Note that, as indicated by the double arrows A in FIG. 8, the reason why the voltage value of the input voltage Vin and the voltage value of the charging voltage Vc are different is due to the voltage drop caused by the resistor R1 connected to the capacitor C1.

[0049] In this way, in the solid-state relay device 2, when the semiconductor switch element SW1 is controlled to turn on and the peak value of the voltage between the output terminals T1 and T2 of the solid-state relay device 2 drops to about 1 V, the output of the predetermined DC voltage Vd from the AC / DC converter 61 stops. However, a capacitor C1 is provided in the solid-state relay device 2 so that the DC drive voltage Vout supplied to the control unit 5 does not fall below the allowable range.

[0050] At time t23, the temperature control device 3 transmits an output off signal to the solid-state relay device 2. In the solid-state relay device 2, the wireless transceiver circuit 51 receives the output off signal, the control circuit 52 sets the trigger signal S1 to the L level, and controls the semiconductor switch element SW1 to turn off. As a result, the output voltage of the series circuit of the AC power supply 10 and the heater 11 can be obtained, and a predetermined DC voltage Vd is output from the AC / DC converter 61 to the capacitor C1 and the DC / DC converter 62. Thereby, the capacitor C1 is charged again, and the charging voltage Vc of the capacitor C1 rises. The DC / DC converter 62 converts the predetermined DC voltage Vd serving as the input voltage Vin into a DC drive voltage Vout and outputs it to the control unit 5.

[0051] At time t24, the temperature control device 3 transmits an output on signal to the solid-state relay device 2. Similar to time t22, the semiconductor switch element SW1 is controlled to turn on. The charging voltage Vc of the capacitor C1 is input to the DC / DC converter 62, and the DC / DC converter 62 converts the charging voltage Vc of the capacitor C1 into a DC drive voltage Vout and supplies it to the control unit 5.

[0052] At time t25, the temperature control device 3 transmits an output off signal to the solid-state relay device 2. Similar to time t23, the semiconductor switch element SW1 is controlled to turn off. The capacitor C1 is charged with the predetermined DC voltage Vd from the AC / DC converter 61, and the charging voltage Vc of the capacitor C1 rises. The DC / DC converter 62 converts the predetermined DC voltage Vd into a DC drive voltage Vout and outputs it to the control unit 5.

[0053] At time t26, the power switch 12 is turned off, and the power supply from the AC power supply 10 stops. In the solid-state relay device 2, the predetermined DC voltage Vd is no longer output from the AC / DC converter 61 of the power supply unit 6, the capacitor C1 also discharges, and the charging voltage Vc decreases. As a result, the input voltage Vin of the DC / DC converter 62 also decreases.

[0054] At a subsequent time t27, the voltage value of the input voltage Vin becomes equal to or less than a predetermined threshold voltage value V2 of the voltage drop detection circuit 53, and at time t28, it becomes equal to or less than a voltage value V3 required for the DC / DC converter 62 to generate the DC drive voltage Vout. When the voltage value of the input voltage Vin becomes equal to or less than the voltage value V3, the voltage value of the DC drive voltage Vout output from the DC / DC converter 62 decreases from the target voltage value V4 of the DC drive voltage Vout, and the control unit 5 also stops operating.

[0055] [1.1.3 Another configuration example] As described above, in the solid-state relay device 2, the communication between the temperature control device 3 and the solid-state relay device 2 is wireless. Therefore, a cable for communication between the temperature control device 3 and the solid-state relay device 2 is unnecessary. The solid-state relay device 2 drives the control unit 5 having the wireless transmission / reception circuit 51 and the control circuit 52 with a DC drive voltage Vout generated by the power supply unit 6 based on the output voltage of the series circuit of the AC power supply 10 and the heater 11. Therefore, a power supply cable between the temperature control device 3 and the solid-state relay device 2 is also unnecessary, and the degree of freedom in arranging the solid-state relay device 2 is improved. Furthermore, even when a plurality of solid-state relay devices 2 are controlled by one temperature control device 3, it is not restricted by the output current capacity of the temperature control device 3. The number of solid-state relay devices 2 controlled by one temperature control device 3 is not limited by the output current capacity of the temperature control device 3. Therefore, the number of solid-state relay devices 2 that can be controlled by one temperature control device 3 can be increased.

[0056] FIG. 9 is a block diagram showing another configuration example of the temperature control system 1. The temperature control system 1 in FIG. 9 includes a plurality of solid state relay devices 2 and one temperature control device 3. As shown in FIG. 9, each solid state relay device 2 is connected in series to an AC power supply 10 and a heater 11. Each of the plurality of solid state relay devices 2 is assigned unique identification information, and the temperature control device 3 uses the identification information to individually transmit a wireless control signal to the plurality of solid state relay devices 2. The temperature control device 3 individually controls the on / off states of the plurality of solid state relay devices 2 to adjust the amount of power supplied from the AC power supply 10 to the heater 11, thereby adjusting the temperature of the object to be heated.

[0057] [1.1.4 Effects, etc.] The solid state relay device 2 described above includes a semiconductor switch element SW1 that is connected to both ends of a series circuit of the AC power supply 10 and the heater 11 to open and close the current path between the AC power supply 10 and the heater 11, a wireless reception circuit (wireless transceiver circuit 51) that receives a wireless control signal from the temperature control device 3, and a control circuit 52 that controls the semiconductor switch element SW1 based on the wireless control signal received by the wireless reception circuit (wireless transceiver circuit 51). The control unit 5 further includes a power supply unit 6 that generates a DC drive voltage Vout for driving the control unit 5 based on the output voltage of the series circuit of the AC power supply 10 and the heater 11 and supplies the DC drive voltage Vout to the control unit 5. According to this configuration, the cable cost and wiring cost between the temperature control device 3 and the solid state relay device 2 can be reduced, the degree of freedom in arranging the solid state relay device 2 can be improved, and furthermore, the number of solid state relay devices 2 that can be controlled by one temperature control device 3 can be increased.

[0058] Also, in the solid state relay device 2, the power supply unit 6 includes an AC / DC converter 61 that converts the output voltage of the series circuit of the AC power supply 10 and the heater 11 into a predetermined DC voltage Vd and outputs it, a capacitor C1 charged with the predetermined DC voltage Vd output from the AC / DC converter 61, and a DC / DC converter 62 that converts the predetermined DC voltage Vd output from the AC / DC converter 61 or the charging voltage Vc of the capacitor C1 into a DC drive voltage Vout and outputs it. According to this configuration, even when the AC / DC converter 61 cannot output a predetermined DC voltage Vd when the semiconductor switch element SW1 is on, the DC drive voltage Vout can be generated using the charging voltage Vc of the capacitor C1, so that a stable power supply to the control unit 5 becomes possible.

[0059] Also, in the solid state relay device 2, after the control circuit 52 starts operating with the DC drive voltage Vout supplied from the power supply unit 6, until a predetermined charging time longer than the time it takes for the charging voltage Vc of the capacitor C1 to become equal to or higher than the voltage required for the DC / DC converter 62 to generate the DC drive voltage Vout has elapsed, the semiconductor switch element SW1 is controlled to be off. According to this configuration, the operating stability of the solid state relay device 2 can be improved.

[0060] Also, in the solid state relay device 2, the control unit 5 has a voltage drop detection circuit 53 that outputs a voltage drop signal to the control circuit 52 when the voltage value of the input voltage Vin of the DC / DC converter 62 becomes equal to or lower than a predetermined threshold voltage value set based on the voltage value required for the DC / DC converter 62 to generate the DC drive voltage Vout. When the control circuit 52 receives the voltage drop signal from the voltage drop detection circuit 53, it controls the semiconductor switch element SW1 to be off. According to this configuration, before the DC drive voltage Vout cannot be generated by the DC / DC converter 62 due to the stop of the AC power supply 10 or the decrease in the charging voltage Vc of the capacitor C1, etc., the semiconductor switch element SW1 is controlled to be off, so that the safety of the solid state relay device 2 can be improved.

[0061] The above-mentioned fixed temperature control system 1 is a temperature control system including a solid-state relay device 2, and further includes a temperature control device 3. According to this configuration, the cable cost and wiring cost between the temperature control device 3 and the solid-state relay device 2 can be reduced, the degree of freedom in arranging the solid-state relay device 2 can be improved, and further, the number of solid-state relay devices 2 that can be controlled by one temperature control device 3 can be increased.

[0062] [1.2 Embodiment 2] [1.2.1 Configuration] The solid-state relay device 2 according to this embodiment has the same configuration as the solid-state relay device 2 according to Embodiment 1 shown in FIG. 1, but the operation of the control circuit 52 is different.

[0063] In Embodiment 2, when the processing circuit 33 of the temperature control device 3 turns on the semiconductor switch element SW1 of the solid-state relay device 2, it transmits an output on-signal to the solid-state relay device 2 through the wireless transmission / reception circuit 32. When the processing circuit 33 of the temperature control device 3 turns on the semiconductor switch element SW1 of the solid-state relay device 2 even after a certain time has passed since transmitting the output on-signal, it transmits the output on-signal to the solid-state relay device 2 again through the wireless transmission / reception circuit 32. Thus, when the temperature control device 3 maintains the semiconductor switch element SW1 in the on state for a predetermined period, it repeats the transmission of the output on-signal at a predetermined time interval for the predetermined period. The predetermined time interval is, for example, 5 seconds.

[0064] In the solid-state relay device 2 according to the present embodiment, when the wireless transceiver circuit 51 does not receive the output on-signal even after a predetermined standby time has elapsed since the wireless transceiver circuit 51 received the output on-signal, the control circuit 52 controls the semiconductor switch element SW1 to turn off. The predetermined standby time is set to a time suitable for determining whether the transmission of the output on-signal by the temperature control device 3 has stopped. The predetermined standby time is set, for example, to be longer than a predetermined time interval at which the temperature control device 3 repeats the transmission of the output on-signal. The predetermined standby time may be set, for example, to be shorter than twice the predetermined time interval. When the wireless transceiver circuit 51 does not receive the output on-signal even after the predetermined standby time has elapsed, there is a high possibility that the temperature control device 3 is in an abnormal state such as a failure. Therefore, the control circuit 52 executes a process of controlling the semiconductor switch element SW1 to turn off for safety reasons.

[0065] FIG. 10 is a flowchart showing an example of the operation of the control circuit 52 of the solid-state relay device 2 according to Embodiment 2.

[0066] After the control circuit 52 starts operating with the DC drive voltage Vout supplied from the power supply unit 6, until a predetermined charging time elapses, the control circuit 52 sets the trigger signal S1 to the L level (S21).

[0067] After step S21, when the wireless transceiver circuit 51 receives the output on-signal (YES in S22), the control circuit 52 sets the trigger signal S1 to the H level (S31). Further, the control circuit 52 starts a timer to measure a predetermined standby time (S32).

[0068] When the counting of the timer ends (YES in S33), the control circuit 52 sets the trigger signal S1 to the L level (S26). That is, when the wireless transceiver circuit 51 does not receive the output on-signal even after a predetermined standby time has elapsed since the wireless transceiver circuit 51 received the output on-signal, the control circuit 52 controls the semiconductor switch element SW1 to turn off.

[0069] Before the timer finishes counting (NO in S33), when the wireless transceiver circuit 51 receives an output on signal (YES in S24), the control circuit 52 restarts the timer to measure a predetermined waiting time again (S35), and returns to step S33. Before the timer finishes counting (NO in S33), when the wireless transceiver circuit 51 receives an output off signal (YES in S36), the control circuit 52 sets the trigger signal S1 to the L level (S24). Before the timer finishes counting (NO in S33), when receiving a voltage drop signal from the voltage drop detection circuit 53 (YES in S36), the control circuit 52 sets the trigger signal S1 to the L level (S26).

[0070] After step 21, when the wireless transceiver circuit 51 receives an output off signal (YES in S23), the control circuit 52 sets the trigger signal S1 to the L level (S24). After step 21, when receiving a voltage drop signal from the voltage drop detection circuit 53 (YES in S25), the control circuit 52 sets the trigger signal S1 to the L level (S26).

[0071] Next, an example of the operation of the control circuit 52 will be briefly described with reference to FIG. 11. FIG. 11 is a timing chart for explaining an example of the operation of the control circuit 52.

[0072] At time t31, the temperature control device 3 transmits an output on signal to turn on the semiconductor switch element SW1 of the solid state relay device 2. The wireless transceiver circuit 51 receives this output on signal, and the control circuit 52 sets the trigger signal S1 to the H level.

[0073] At time t32, the temperature control device 3 transmits an output on signal again to continue the on state of the semiconductor switch element SW1 of the solid state relay device 2, and the wireless transceiver circuit 51 receives this output off signal. As a result, the control circuit 52 continues the state where the trigger signal S1 is at the H level.

[0074] At time t33, the temperature control device 3 transmits an output on-signal again in order to continue the on-state of the semiconductor switch element SW1 of the solid-state relay device 2. Similar to time t32, the control circuit 52 continues the state where the trigger signal S1 is at the H level.

[0075] At time t34, the temperature control device 3 transmits an output off-signal to turn off the semiconductor switch element SW1 of the solid-state relay device 2. The wireless transceiver circuit 51 receives this output off-signal, and the control circuit 52 sets the trigger signal S1 to the L level.

[0076] At time t35, the temperature control device 3 transmits an output on-signal to turn on the semiconductor switch element SW1 of the solid-state relay device 2. Similar to time t31, the control circuit 52 sets the trigger signal S1 to the H level.

[0077] At time t36, since a predetermined standby time has elapsed after the wireless transceiver circuit 51 receives the output on-signal, the control circuit 52 sets the trigger signal S1 to the L level and controls the semiconductor switch element SW1 to turn off.

[0078] [1.2.2 Effects, etc.] In the above-mentioned solid state relay device 2, when the wireless control signal received by the wireless reception circuit (wireless transmission / reception circuit 51) is an output on signal, the control circuit 52 controls the semiconductor switch element SW1 to turn on, and when the wireless control signal received by the wireless reception circuit (wireless transmission / reception circuit 51) is an output off signal, the control circuit 52 controls the semiconductor switch element SW1 to turn off. When the wireless reception circuit (wireless transmission / reception circuit 51) does not receive the output on signal even after a predetermined standby time has elapsed since the wireless reception circuit (wireless transmission / reception circuit 51) received the output on signal, the control circuit 52 controls the semiconductor switch element SW1 to turn off. According to this configuration, even when the wireless reception circuit (wireless transmission / reception circuit 51) cannot receive the wireless control signal corresponding to the output on command due to an abnormal state of the temperature control device 3 or the like, the control circuit 52 controls the semiconductor switch element SW1 to turn off after a predetermined standby time has elapsed, so that safety can be improved.

[0079] Further, when the temperature control device 3 maintains the semiconductor switch element SW1 in the on state for a predetermined period, the temperature control device 3 repeats the transmission of the output on signal at a predetermined time interval for the predetermined period. The predetermined standby time is set longer than the predetermined time interval. According to this configuration, safety can be further improved.

[0080] [1.3 Embodiment 3] [1.3.1 Configuration] FIG. 12 is a block diagram showing a configuration example of a temperature control system 1A including a solid state relay device 2A according to Embodiment 3. The temperature control system 1A includes a solid state relay device 2A and a temperature control device 3.

[0081] In the temperature control system 1 of Embodiment 1, the exchange of information between the temperature control device 3 and the solid-state relay device 2 is only the transmission of a wireless control signal indicating control information from the temperature control device 3 to the solid-state relay device 2, and the solid-state relay device 2 does not transmit information to the temperature control device 3. In this embodiment, the solid-state relay device 2A has a function of transmitting information to the temperature control device 3 by a wireless signal, and the solid-state relay device 2A can transmit the abnormal state information regarding the solid-state relay device 2A to the temperature control device 3.

[0082] The temperature control device 3 according to this embodiment has the same configuration as the temperature control device 3 according to Embodiment 1 shown in FIG. 2, but the operation of the processing circuit 33 is different.

[0083] The processing circuit 33 receives a wireless signal from the solid-state relay device 2A through the wireless transceiver circuit 32. In this embodiment, the wireless signal from the solid-state relay device 2A indicates the abnormal state information regarding the solid-state relay device 2A. Although it will be described in detail later, this abnormal state information is information regarding the abnormal state of the semiconductor switch element SW1 of the solid-state relay device 2A. The abnormal state of the semiconductor switch element SW1 is, for example, an open fault of the semiconductor switch element SW1 and a short fault of the semiconductor switch element SW1.

[0084] In addition to the temperature control process, the processing circuit 33 performs an abnormal state notification process. The abnormal state notification process is a process of presenting the abnormal state information indicated by the wireless signal received by the wireless transceiver circuit 32 by the input / output device 31. For example, when the abnormal state information is an open fault of the semiconductor switch element SW1, the processing circuit 33 displays a message indicating that an open fault of the semiconductor switch element SW1 has occurred on the display of the input / output device 31. For example, when the abnormal state information is a short fault of the semiconductor switch element SW1, the processing circuit 33 displays a message indicating that a short fault of the semiconductor switch element SW1 has occurred on the display of the input / output device 31.

[0085] FIG. 13 is a circuit diagram showing a configuration example of the solid state relay device 2A of FIG. 12. As shown in FIG. 13, the solid state relay device 2A includes a switch unit 4, a control unit 5A, and a power supply unit 6.

[0086] The control unit 5A includes a wireless transceiver circuit 51, a control circuit 52A, a voltage drop detection circuit 53, a switch SW2, a voltage detection circuit 54, and a current detection circuit 55.

[0087] The wireless transceiver circuit 51 is a wireless transmission circuit that transmits a wireless signal to the temperature control device 3. The wireless transceiver circuit 51 is connected to an antenna 51A and transmits a wireless signal to the temperature control device 3 through the antenna 51A. In the present embodiment, the wireless transceiver circuit 51 is used for transmitting abnormal state information from the solid state relay device 2A to the temperature control device 3.

[0088] The voltage detection circuit 54 detects the voltage Vo between the output terminals T1 and T2 and outputs a voltage detection signal indicating the voltage Vo between the output terminals T1 and T2 to the control circuit 52A. The voltage Vo between the output terminals T1 and T2 corresponds to the voltage across the semiconductor switch element SW1. The voltage detection circuit 54 is configured to include, for example, a voltage dividing circuit connected between the output terminals T1 and T2.

[0089] The current detection circuit 55 detects the current Io flowing through the semiconductor switch element SW1 and outputs a current detection signal indicating the current Io to the control circuit 52A. The current detection circuit 55 is configured to include, for example, a shunt resistor or a current transformer connected in series with the semiconductor switch element SW1.

[0090] In addition to controlling the semiconductor switch element SW1 in the same manner as the control circuit 52 in Embodiment 1 or Embodiment 2, the control circuit 52A performs an abnormal state detection operation. The control circuit 52A performs the abnormal state detection operation by interrupt processing every fixed time (for example, 50 ms) in parallel with the operation of controlling the semiconductor switch element SW1. In the abnormal state detection operation, the control circuit 52A determines whether the semiconductor switch element SW1 is in an abnormal state. When the control circuit 52A determines that the semiconductor switch element SW1 is in an abnormal state, the control circuit 52A controls the wireless transceiver circuit 51 to transmit a wireless signal including abnormal state information indicating the abnormal state of the semiconductor switch element SW1 to the temperature control device 3. In the present embodiment, the abnormal state of the semiconductor switch element SW1 is an open failure of the semiconductor switch element SW1 and a short failure of the semiconductor switch element SW1.

[0091] An open failure is a state in which the semiconductor switch element SW1 remains off and cannot turn on. When the semiconductor switch element SW1 is in a normal state, when the control circuit 52A sets the trigger signal S1 to the H level, the semiconductor switch element SW1 turns on, so the peak value of the voltage Vo between the output terminals T1 and T2 becomes smaller than the peak value of the AC voltage of the AC power supply 10, for example, about 1.5 V or less. When an open failure occurs, the semiconductor switch element SW1 remains off even when the control circuit 52A sets the trigger signal S1 to the H level, so the peak value of the voltage Vo between the output terminals T1 and T2 becomes almost equal to the peak value of the output voltage of the series circuit of the AC power supply 10 and the heater 11.

[0092] While the control circuit 52A sets the trigger signal S1 to the H level, it determines whether there is an open fault in the semiconductor switch element SW1 based on the voltage Vo between the output terminals T1 and T2. In the present embodiment, while the control circuit 52 sets the trigger signal S1 to the H level, it determines whether there is an open fault in the semiconductor switch element SW1 based on the voltage Vo indicated by the voltage detection signal from the voltage detection circuit 54. The control circuit 52 determines that an open fault has occurred when the condition that the voltage Vo while the trigger signal S1 is set to the H level is greater than a predetermined voltage threshold Vth is satisfied. Since the voltage Vo is an AC voltage, for example, the amplitude or peak value of the voltage Vo is used for comparison with the predetermined voltage threshold Vth. The predetermined voltage threshold Vth is, for example, greater than the voltage Vo between the output terminals T1 and T2 when the semiconductor switch element SW1 is on and lower than the voltage Vo between the output terminals T1 and T2 when the semiconductor switch element SW1 is off. However, in order to prevent false alarms due to noise or the like, the control circuit 52 determines that an open fault has occurred when the condition that the voltage Vo while the trigger signal S1 is set to the H level is greater than the predetermined voltage threshold Vth is satisfied continuously for a predetermined number of times. The predetermined number of times may be, for example, 5 times.

[0093] When the control circuit 52A detects an open fault in the semiconductor switch element SW1, it controls the wireless transceiver circuit 51 so that the wireless transceiver circuit 51 transmits a wireless signal indicating the open fault of the semiconductor switch element SW1 to the temperature control device 3.

[0094] A short circuit fault is a state in which the semiconductor switch element SW1 remains on and does not turn off. When the semiconductor switch element SW1 is in a normal state, when the control circuit 52A sets the trigger signal S1 to the L level, the semiconductor switch element SW1 turns off, so no current flows through the semiconductor switch element SW1. When a short circuit fault occurs, even when the control circuit 52A sets the trigger signal S1 to the L level, the semiconductor switch element SW1 remains on, so current flows through the semiconductor switch element SW1.

[0095] While the control circuit 52A sets the trigger signal S1 to the L level, it determines a short-circuit fault of the semiconductor switch element SW1 based on the current Io flowing through the semiconductor switch element SW1. In the present embodiment, while the control circuit 52A sets the trigger signal S1 to the L level, it determines a short-circuit fault of the semiconductor switch element SW1 based on the current Io flowing through the semiconductor switch element SW1 indicated by the current detection signal from the current detection circuit 55. When the condition that the current Io flowing through the semiconductor switch element SW1 while the control circuit 52A sets the trigger signal S1 to the L level is greater than a predetermined current threshold Ith is satisfied, the control circuit 52A determines that a short-circuit fault has occurred. Since the current Io is an alternating current, for example, the amplitude or peak value of the current Io is used for comparison with the predetermined current threshold Ith. The predetermined current threshold Ith may be, for example, a value that can discriminate the presence or absence of current, for example, 0.1 A. However, in order to prevent false alarms due to noise or the like, when the condition that the current Io flowing through the semiconductor switch element SW1 while the control circuit 52A sets the trigger signal S1 to the L level is greater than the predetermined current threshold Ith is continuously satisfied a predetermined number of times, the control circuit 52A determines that a short-circuit fault has occurred. The predetermined number of times may be, for example, 5 times.

[0096] When the control circuit 52A detects a short-circuit fault of the semiconductor switch element SW1, it controls the wireless transceiver circuit 51 so that the wireless transceiver circuit 51 transmits a wireless signal indicating the short-circuit fault of the semiconductor switch element SW1 to the temperature control device 3.

[0097] [1.3.2 Operation] Next, an example of the abnormal state detection operation by the control circuit 52A will be briefly described with reference to FIG. 14. FIG. 14 is a flowchart showing an example of the abnormal state detection operation.

[0098] When starting the abnormal state detection operation, the control circuit 52A determines whether the trigger signal is at the H level (S41).

[0099] When the trigger signal is at the H level in step S41, the control circuit 52A compares the voltage Vo indicated by the voltage detection signal input from the voltage detection circuit 54 with a predetermined voltage threshold Vth (S42). If the voltage Vo is less than or equal to the predetermined voltage threshold Vth, the control circuit 52A resets the counter value CV1 to 0 (S43). If the voltage Vo exceeds the predetermined voltage threshold Vth, the control circuit 52A increments the counter value CV1 by 1 (S44). When the counter value CV1 becomes equal to or greater than the specified value CV1th (YES in S45), the control circuit 52A determines that an open failure has occurred, and controls the wireless transceiver circuit 51 so that the wireless transceiver circuit 51 transmits a wireless signal indicating the open failure of the semiconductor switch element SW1 to the temperature control device 3 (S46). The specified value CV1th is, for example, 5.

[0100] When the trigger signal is at the L level in step S41, the control circuit 52A compares the current Io indicated by the current detection signal input from the current detection circuit 55 with a predetermined current threshold Ith (S52). If the current Io is less than or equal to the predetermined current threshold Ith, the control circuit 52A resets the counter value CV2 to 0 (S53). If the current Io exceeds the predetermined current threshold Ith, the control circuit 52A increments the counter value CV2 by 1 (S54). When the counter value CV2 becomes equal to or greater than the specified value CV2th (YES in S55), the control circuit 52A determines that a short failure has occurred, and controls the wireless transceiver circuit 51 so that the wireless transceiver circuit 51 transmits a wireless signal indicating the short failure of the semiconductor switch element SW1 to the temperature control device 3 (S56). The specified value CV2th is, for example, 5.

[0101] [1.3.3 Effects, etc.] In the above-described solid-state relay device 2A, the control unit 5A includes a wireless transmission circuit (wireless transceiver circuit 51) that transmits a wireless signal to the temperature control device 3. When the control circuit 52A detects an abnormal state of the semiconductor switch element SW1, the wireless transmission circuit (wireless transceiver circuit 51) is controlled to transmit a wireless signal including the abnormal state information indicating the abnormal state of the semiconductor switch element SW1 to the temperature control device 3. According to this configuration, information regarding the abnormal state of the semiconductor switch element SW1 can be transmitted to the temperature control device 3.

[0102] Also, the abnormal state of the semiconductor switch element SW1 is at least one of an open fault and a short fault. According to this configuration, at least one of the open fault and the short fault of the semiconductor switch element SW1 can be transmitted to the temperature control device 3.

[0103] [2. Modification Example] The embodiments of the present disclosure are not limited to the above-described embodiments. The above-described embodiments can be variously modified according to the design and the like as long as the problems of the present disclosure can be achieved. Hereinafter, modification examples of the above-described embodiments will be listed. The modification examples described below can be applied in appropriate combinations.

[0104] In one modification example, the configuration of the switch unit 4 of the solid-state relay device 2 is not particularly limited. The semiconductor switch element SW1 is not limited to a triac, and may be configured to include a thyristor, a MOSFET, or the like. The switch unit 4 does not necessarily need to include a zero-cross circuit 42.

[0105] In a modification, the control unit 5 of the solid-state relay device 2 may not include the voltage drop detection circuit 53. The wireless communication method of the wireless transmission / reception circuit 51 is not particularly limited. In the modifications of Embodiments 1 and 2, the wireless transmission / reception circuit 51 does not necessarily have the function as a wireless transmission circuit. In the solid-state relay device 2, for example, the control circuit 52 may not transmit the ACK signal to the temperature control device 3 by the wireless transmission / reception circuit 51. In this case, the wireless transmission / reception circuit 51 may be replaced with a wireless reception circuit, and the wireless transmission / reception circuit 32 of the temperature control device 3 may be replaced with a wireless transmission circuit.

[0106] In a modification, the configuration of the power supply unit 6 of the solid-state relay device 2 is not particularly limited. The AC / DC converter 61 is not limited to the configuration described in Embodiment 1, and may be, for example, a circuit configuration of a conventionally well-known AC / DC converter. The DC / DC converter 62 is not limited to a series regulator, and may be a circuit configuration of a conventionally well-known DC / DC converter.

[0107] In a modification of Embodiment 3, the abnormal state of the semiconductor switch element SW1 may be at least one of an open fault and a short fault, rather than both an open fault and a short fault. The abnormal state information is not limited to an open fault and a short fault. The abnormal state information may be information on an abnormal state related to the solid-state relay device 2A. The abnormal state information may be, for example, error information of the control unit 5A or information on a heat dissipation abnormal state. The control unit 5A may not include the voltage detection circuit 54 and the current detection circuit 55, and may have a circuit capable of detecting the target abnormal state information.

[0108] [3. Aspect] As is apparent from the above embodiments and modifications, the present disclosure includes the following aspects. Hereinafter, for the sole purpose of clarifying the correspondence with the embodiments, reference numerals are attached in parentheses.

[0109] The first aspect is a solid state relay device (2; 2A), which is connected to a series circuit of an AC power supply (10) and a heater (11) and opens and closes a current path between the AC power supply (10) and the heater (11). It includes a semiconductor switch element (SW1), a wireless receiving circuit (wireless transceiver circuit 51) that receives a wireless control signal from a temperature control device (3), and a control unit (5; 5A) having a control circuit (52; 52A) that controls the semiconductor switch element (SW1) based on the wireless control signal received by the wireless receiving circuit (wireless transceiver circuit 51). It also includes a power supply unit (6) that generates a DC drive voltage (Vout) for driving the control unit (5; 5A) based on the output voltage of the series circuit of the AC power supply (10) and the heater (11) and supplies it to the control unit (5). According to this aspect, the cable cost and wiring cost between the temperature control device (3) and the solid state relay device (2; 2A) can be reduced, the degree of freedom in arranging the solid state relay device (2; 2A) can be improved, and furthermore, the number of solid state relay devices (2; 2A) that can be controlled by one temperature control device (3) can be increased.

[0110] The second aspect is a solid state relay device (2; 2A) based on the first aspect. In the second aspect, the power supply unit (6) includes an AC / DC converter (61) that converts the output voltage of the series circuit of the AC power supply (10) and the heater (11) into a predetermined DC voltage (Vd) and outputs it, a capacitor (C1) charged with the predetermined DC voltage (Vd) output from the AC / DC converter (61), and a DC / DC converter (62) that converts the predetermined DC voltage (Vd) output from the AC / DC converter (61) or the charging voltage (Vc) of the capacitor (C1) into the DC drive voltage (Vout) and outputs it. According to this configuration, even when the AC / DC converter (61) cannot output a predetermined DC voltage (Vd) when the semiconductor switch element (SW1) is on, the DC drive voltage (Vout) can be generated using the charging voltage (Vc) of the capacitor (C1), so that a stable power supply to the control unit (5; 5A) becomes possible.

[0111] The third aspect is a solid-state relay device (2; 2A) based on the second aspect. In the third aspect, after the control circuit (52; 52A) starts operating with the DC drive voltage (Vout) supplied from the power supply unit (6), until a predetermined charging time longer than the time it takes for the charging voltage (Vc) of the capacitor (C1) to reach or exceed the voltage required for the DC / DC converter (62) to generate the DC drive voltage (Vout) has elapsed, the semiconductor switch element (SW1) is controlled to be off. According to this aspect, the operating stability of the solid-state relay device (2; 2A) can be improved.

[0112] The fourth aspect is a solid-state relay device (2; 2A) based on the second or third aspect. In the fourth aspect, the control unit (5; 5A) has a voltage drop detection circuit (53) that outputs a voltage drop signal to the control circuit (52; 52A) when the voltage value of the input voltage (Vin) of the DC / DC converter (62) becomes equal to or lower than a predetermined threshold voltage value set based on the voltage value required for the DC / DC converter (62) to generate the DC drive voltage (Vout). When the control circuit (52; 52A) receives the voltage drop signal from the voltage drop detection circuit (53), it controls the semiconductor switch element (SW1) to be off. According to this aspect, since the semiconductor switch element (SW1) is controlled to be off before the DC drive voltage (Vout) stops being generated by the DC / DC converter (62) due to the stop of the AC power supply (10) or the like, safety can be improved.

[0113] The fifth aspect is a solid-state relay device (2; 2A) based on any one of the first to fourth aspects. In the fifth aspect, when the wireless control signal received by the wireless reception circuit (wireless transmission / reception circuit 51) is an output on signal, the control circuit (52; 52A) controls the semiconductor switch element (SW1) to turn on, and when the wireless control signal received by the wireless reception circuit (wireless transmission / reception circuit 51) is an output off signal, the control circuit (52; 52A) controls the semiconductor switch element (SW1) to turn off. When the wireless reception circuit (wireless transmission / reception circuit 51) has not received the output on signal even after a predetermined standby time has elapsed since the wireless reception circuit (wireless transmission / reception circuit 51) received the output on signal, the control circuit (52; 52A) controls the semiconductor switch element (SW1) to turn off. According to this aspect, even when the wireless reception circuit (wireless transmission / reception circuit 51) cannot receive the output on signal due to a failure of the temperature control device (3) or the like, the control circuit (52; 52A) controls the semiconductor switch element (SW1) to turn off after the predetermined standby time has elapsed, so that safety can be improved.

[0114] The sixth aspect is a solid-state relay device (2; 2A) based on the fifth aspect. In the sixth aspect, when the temperature control device (3) maintains the semiconductor switch element (SW1) on for a predetermined period, the output on signal is transmitted repeatedly at a predetermined time interval during the predetermined period. The predetermined standby time is set longer than the predetermined time interval. According to this aspect, safety can be further improved.

[0115] The seventh aspect is a solid-state relay device (2A) based on any one of the first to sixth aspects. In the seventh aspect, the control unit (5A) has a wireless transmission circuit (wireless transceiver circuit 51) that transmits a wireless signal to the temperature control device (3). When the control circuit (52A) detects an abnormal state of the semiconductor switch element (SW1), the wireless transmission circuit (wireless transceiver circuit 51) is controlled to transmit a wireless signal including abnormal state information indicating the abnormal state of the semiconductor switch element (SW1) to the temperature control device (3). According to this aspect, the abnormal state information regarding the abnormal state of the semiconductor switch element (SW1) can be transmitted to the temperature control device (3).

[0116] The eighth aspect is a solid-state relay device (2A) based on the seventh aspect. In the eighth aspect, the abnormal state of the semiconductor switch element (SW1) is at least one of an open fault and a short circuit fault. According to this aspect, at least one of the open fault and the short circuit fault of the semiconductor switch element (SW1) can be transmitted to the temperature control device (3).

[0117] The ninth aspect is a temperature control system (1; 1A) including a solid-state relay device (2; 2A) based on any one of the first to eighth aspects, further including the temperature control device (3).

Industrial Applicability

[0118] The present disclosure is applicable to a solid-state relay device and a temperature control system. Specifically, the present disclosure is applicable to a solid-state relay device and a temperature control system for controlling power supply from an AC power source to a heater according to control information from a temperature control device.

Explanation of Reference Numerals

[0119] 1, 1A Temperature control system 2, 2A Solid-state relay device 3 Temperature control device 5, 5A Control unit 51 Wireless transceiver circuit (wireless receiver circuit, wireless transmitter circuit) 52, 52A Control circuit 53 Voltage drop detection circuit 6 Power supply unit 61 AC / DC converter 62 DC / DC converter SW1 Semiconductor switch element C1 Capacitor 10 AC power supply 11 Heater Vd Predetermined DC voltage Vc Charging voltage Vout DC drive voltage

Claims

1. A semiconductor switch element connected across both ends of a series circuit of an AC power supply and a heater to open and close a current path between the AC power supply and the heater, a control unit having a wireless reception circuit that receives a wireless control signal from a temperature control device, and a control circuit that controls the semiconductor switch element based on the wireless control signal received by the wireless reception circuit, a power supply unit that generates a DC drive voltage for driving the control unit based on an output voltage of the series circuit of the AC power supply and the heater and supplies the DC drive voltage to the control unit, comprising: the power supply unit includes an AC / DC converter that converts an output voltage of the series circuit of the AC power supply and the heater into a predetermined DC voltage and outputs it, a capacitor charged with the predetermined DC voltage output from the AC / DC converter, and a DC / DC converter that converts the predetermined DC voltage output from the AC / DC converter or the charging voltage of the capacitor into the DC drive voltage and outputs it, having: the control unit has a voltage drop detection circuit that outputs a voltage drop signal to the control circuit when a voltage value of an input voltage of the DC / DC converter becomes equal to or lower than a predetermined threshold voltage value set based on a voltage value required for the DC / DC converter to generate the DC drive voltage, when the control circuit receives a voltage drop signal from the voltage drop detection circuit, it controls the semiconductor switch element to turn off. Solid state relay device.

2. A semiconductor switch element connected across both ends of a series circuit of an AC power supply and a heater to open and close a current path between the AC power supply and the heater, a control unit having a wireless reception circuit that receives a wireless control signal from a temperature control device, and a control circuit that controls the semiconductor switch element based on the wireless control signal received by the wireless reception circuit, a power supply unit that generates a DC drive voltage for driving the control unit based on an output voltage of the series circuit of the AC power supply and the heater and supplies the DC drive voltage to the control unit, comprising: when the wireless control signal received by the wireless reception circuit is an output on signal, the control circuit controls the semiconductor switch element to turn on, and when the wireless control signal received by the wireless reception circuit is an output off signal, the control circuit controls the semiconductor switch element to turn off, when the wireless reception circuit does not receive the output on signal even after a predetermined standby time has elapsed since the wireless reception circuit received the output on signal, the control circuit controls the semiconductor switch element to turn off. Solid state relay device.

3. When the temperature adjustment device maintains the semiconductor switch element in the on state for a predetermined period, it repeats the transmission of the output on signal at a predetermined time interval during the predetermined period. The predetermined standby time is set longer than the predetermined time interval. The solid state relay device according to claim 2.

4. A semiconductor switch element connected to both ends of a series circuit of an AC power supply and a heater to open and close the current path between the AC power supply and the heater, A wireless reception circuit that receives a wireless control signal from a temperature adjustment device, and a control unit having a control circuit that controls the semiconductor switch element based on the wireless control signal received by the wireless reception circuit, A power supply unit that generates a DC drive voltage for driving the control unit based on the output voltage of the series circuit of the AC power supply and the heater and supplies the DC drive voltage to the control unit, Comprising: The power supply unit An AC / DC converter that converts the output voltage of the series circuit of the AC power supply and the heater into a predetermined DC voltage and outputs it, A capacitor charged with the predetermined DC voltage output from the AC / DC converter, A DC / DC converter that converts the predetermined DC voltage or the charging voltage of the capacitor output from the AC / DC converter into the DC drive voltage and outputs it, Having: After the control circuit starts operating with the DC drive voltage supplied from the power supply unit, until a predetermined charging time longer than the time it takes for the charging voltage of the capacitor to become equal to or higher than the voltage required for the DC / DC converter to generate the DC drive voltage has elapsed, the control circuit controls the semiconductor switch element to be off. Solid state relay device.

5. A semiconductor switch element connected to both ends of a series circuit of an AC power supply and a heater to open and close the current path between the AC power supply and the heater, A wireless reception circuit that receives a wireless control signal from a temperature adjustment device, and a control unit having a control circuit that controls the semiconductor switch element based on the wireless control signal received by the wireless reception circuit, A power supply unit that generates a DC drive voltage for driving the control unit based on the output voltage of the series circuit of the AC power supply and the heater and supplies the DC drive voltage to the control unit, Comprising: The control unit further has a wireless transmission circuit that transmits a wireless signal to the temperature adjustment device. When the control circuit detects an abnormal state of the semiconductor switch element, the control circuit controls the wireless transmission circuit so that the wireless transmission circuit transmits a wireless signal indicating the abnormal state of the semiconductor switch element to the temperature control device. Solid state relay device.

6. The abnormal state of the semiconductor switch element is at least one of an open fault and a short fault. The solid state relay device according to claim 5.

7. The power supply unit an AC / DC converter that converts the output voltage of the series circuit of the AC power supply and the heater into a predetermined DC voltage and outputs it; a capacitor charged with the predetermined DC voltage output from the AC / DC converter; a DC / DC converter that converts the predetermined DC voltage output from the AC / DC converter or the charging voltage of the capacitor into the DC drive voltage and outputs it; having The solid state relay device according to any one of claims 2, 3, 5, and 6.

8. A temperature control system including the solid state relay device according to any one of claims 1 to 7, further including the temperature control device, Temperature control system.

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