JP2002049402A - Solid state relay and solid state relay terminal using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is necessary for a user to install a CT sensor at a heater, and that the increase of costs or the deterioration of quality is generated due to the increase of assembly man-hours and the complication of its assembly. SOLUTION: It is not necessary to install a CT sensor, and it is possible to insulate a temperature controller 1 from a load power source 9 side by a triac coupler 16 of a solid state relay 2. Also, it is necessary to insulate a load current monitor circuit part 21 from the temperature controller 1 since a resistor 20 of the load current monitor circuit part 21 is integrated into the solid state relay 2. Therefore, a photo-coupler 22 is used at the output side of the load current monitor circuit part 1, and a transformer 24 is integrated into a power source part 25 of the load current monitor circuit part 21 so that it is possible to electrically insulate the temperature controller 1 from the load power source 9 side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid state relay used for an output control device such as a temperature controller output device used for a temperature control device, and a solid state relay terminal using the solid state relay. is there.

[0002]

2. Description of the Related Art In a conventional control device for controlling a temperature, a CT sensor is used as a heater disconnection detecting mechanism in order to prevent problems caused by disconnection of a heating heater or to minimize damage. Is often used.

For example, as shown in FIG. 7, a heater 71 is connected to an output operation device 70 which is an output control device, and the output operation device 70 is controlled by a temperature controller 72. Connect the wiring 73 to the CT sensor 74
When the current is detected by the CT sensor 74 and the current falls below the reference value, it is determined that the wire is broken.

As an output operation device 70, as shown in FIG. 9, a solid state relay SSR is used for an output portion 75, and the output side of a CT sensor 74 inserted into a primary wiring 73 of a heater 71 is directly connected to the output side. As shown in FIG. 10, a solid state relay SSR is used for an output section 75 of the temperature sensor 72, and a CT sensor 74 inserted through a primary wiring 73 of a heater 71 is connected to a failure detection circuit 77, as shown in FIG. The output side of the failure detection circuit 77 is connected to a PLC
There was one connected to the 78 side. Incidentally, 79 is an internal power supply.

[0005]

However, according to the above-described conventional temperature adjustment control device, the primary wire 73 of the heater 71 is inserted into the CT sensor 74, and the insertion is performed by the (1) in FIG. As shown in FIG.
When passing the sensor 74 at right angles to the center of the insertion hole 74a of the sensor 74, the primary wiring 73 is connected to the CT sensor 74 as shown in FIG.
When the wire is passed through the end of the insertion hole 74a at a right angle, the primary wiring 73 is connected to the insertion hole 74 of the CT sensor 74 as shown in FIG.
a, when the primary wiring 73 is obliquely passed through the insertion hole 74a of the CT sensor 74 as shown in FIG. 8 (4), the primary wiring 73 is connected to the CT sensor as shown in FIG. 8 (5). There is a case where it is rotated and passed through the 74 insertion hole 74a.

[0006] Therefore, when the user operates the heater 71 by the CT.
Since the sensor 74 needs to be installed, the number of assembling steps is large and complicated, resulting in an increase in cost and quality. In addition, the shape of the temperature control controller depends on the shape of the CT sensor 74. Tended to grow,
In addition, there is a problem that the price of the temperature adjustment control device increases depending on the cost of the CT sensor 74.

A load current monitoring method that does not use the CT sensor 74 may use a standard resistor (such as a circuit for preventing short-circuiting of output equipment). In this case, the load current is monitored to the control side while maintaining insulation from the load side. There was a problem that a signal could not be transmitted.

The present invention has been made in view of the above problems, and a first object of the present invention is to prevent electric shock even when a control device, for example, a temperature controller is touched by a person. In addition to ensuring safety, the user does not need to install the CT sensor of the current detection unit on the heater to be controlled, which reduces the number of assembly steps and reduces the installation space. An object of the present invention is to provide a solid state relay that contributes to reduction in size.

A second object of the present invention is to provide a solid-state relay terminal using a solid-state relay, which can reduce the number of assembling steps and contribute to reducing the installation space. To provide.

[0010]

In order to achieve the first object, a solid state relay according to the present invention comprises:
An input circuit unit receiving a signal from a control device, and an output circuit unit having a switching element for opening and closing a load current and connected to a load power supply via an output terminal, and comprising an input circuit unit and an output circuit unit Is a solid state relay that is electrically insulated, is provided between the switching element and the output terminal, and a resistor through which a load current flows, and loads a voltage on the resistor to a control device side. A load current monitor circuit for outputting a current monitor signal; and a power supply for driving the load current monitor circuit. Power is supplied to the load current monitor circuit and a load current is monitored from the load current monitor circuit. The output of the signal is performed via an electrical insulating means.

In the solid state relay according to the present invention, it is preferable that the electrical insulation means is a tri-up coupler, a photo coupler, or a transformer.

In the solid state relay according to the present invention, the power supply to the load current monitoring circuit may be performed by the voltage supply from the load side.

In the solid state relay according to the present invention, the load current monitor signal output from the load current monitor circuit is processed in a state before being smoothed,
The output may be performed in a state where the pulse width changes according to the magnitude of the load current.

With this configuration, the power supply to the load current monitor circuit section and the output of the load current monitor signal from the load current monitor circuit section are performed via the electrical insulation means. Thus, the control device side and the load power supply side can be reliably insulated, and safety can be ensured so that even if a control device, for example, a temperature controller is touched by a person, an electric shock is not caused.

Further, it is not necessary for the user to install a CT sensor of the current detecting unit on the heater or the like to be controlled,
The number of assembly steps can be reduced, and the installation space can be reduced. The user has to perform complicated work such as passing or winding an electric wire as a primary penetration wire through a CT sensor when assembling the device. The process can be omitted.

In order to achieve the first object, a solid state relay according to the present invention has an input circuit for receiving a signal from a control device, a switching element for switching a load current, and a load. A solid-state relay comprising an output circuit connected to the power supply via an output terminal, wherein the input circuit and the output circuit are electrically insulated from each other. A failure detection circuit unit that outputs a failure detection signal by comparing a control signal from the input circuit unit and a load current detection signal from the resistor side; And a power supply unit for supplying power to the failure detection circuit unit, inputting a control signal from the input circuit unit, and outputting a failure detection signal from the failure detection circuit unit via the electrical insulation means. did Than it is.

In the solid state relay according to the present invention, it is preferable that the electrical insulation means is a tri-up coupler, a photo coupler, or a transformer.

With this configuration, the power supply to the failure detection circuit unit, the input of the control signal from the input circuit unit, and the output of the failure detection signal from the failure detection circuit unit are performed via the electrical insulation means. With this electrical insulation means, the control equipment side and the load power supply side can be electrically insulated reliably, and even if a control equipment, for example, a temperature controller, is touched by humans, safety is ensured so as not to receive an electric shock. Can be secured.

Further, it is not necessary for the user to install a CT sensor of the current detecting unit on the heater or the like to be controlled,
The number of assembly steps can be reduced, and the installation space can be reduced. The user has to perform complicated work such as passing or winding an electric wire as a primary penetration wire through a CT sensor when assembling the device. The process can be omitted.

According to another aspect of the present invention, there is provided a solid state relay terminal according to the present invention, wherein the solid state relay includes an input circuit for receiving a signal from a control device; An output circuit portion insulated from the switching element and connected to the load power supply via an output terminal, and a resistor provided between the switching element and the output terminal and through which the load current flows A load current monitor circuit that processes the voltage at the resistor and outputs the same as a load current monitor signal to the control device;
A power supply unit for driving the load current monitor circuit unit, wherein power supply to the load current monitor circuit unit and output of a load current monitor signal from the load current monitor circuit unit are performed via electrical insulation means. In this configuration, a plurality of solid state relays are connected.

With this configuration, in the solid state relay, the power supply to the load current monitor circuit section and the output of the load current monitor signal from the load current monitor circuit section are performed via the electrical insulation means. With this electrical insulation means, the control device side and the load power supply side can be electrically insulated reliably, and even if a control device, for example, a temperature controller is touched by a person, safety is ensured so as not to receive an electric shock. be able to.

Further, it is not necessary for the user to install the CT sensor of the current detecting unit on the heater to be controlled, so that the number of assembling steps can be reduced, and the installation space can be reduced. It is possible to omit a complicated operation process required for a user to pass or wind an electric wire as a primary penetration wire through a CT sensor when assembling the apparatus.

[0023]

(Embodiment 1) FIG. 1 shows Embodiment 1 of a solid state relay according to the present invention.

The solid state relay (S) according to the present invention
The SR) 2 constitutes a temperature control device by combining a temperature controller 1 which is a control device for controlling the temperature of the control target 4 and a heater 3 which is a heating means for heating the control target 4. The control target 4 is provided with a temperature sensor 5 for detecting the temperature.

As shown in FIG. 2, the temperature controller 1 has a setting section 6 for setting a target temperature and the like, and a display for displaying the current temperature detected by the temperature sensor 5, the target value set by the setting section 6, and the like. Unit 7, an alarm output unit 29A, and a CP that controls the solid state relay 2 such that the current temperature detected by the temperature sensor 5 becomes the target temperature set by the setting unit 6.
U8.

The solid state relay 2 has an input circuit 1 for receiving a control signal from a temperature controller 1 which is a control device.
4A, an output circuit section 14B having a switching element 17 for switching a load current and connected to the load power supply 9 via output terminals T1 and T2, and provided between the switching element 17 and the output terminal T1. And a resistor 20 through which a load current flows, and a load current monitor circuit unit 2 which processes a voltage at the resistor 20 and outputs the processed voltage to the temperature controller 1 as a load current monitor signal.
1 and a power supply unit 25 for driving the load current monitor circuit unit 21. The input circuit unit 14A and the output circuit unit 14B are electrically isolated from each other by a triac unit.
The power is supplied to the load current monitor circuit section 21 via a transformer 24 which is an electrically insulating means, and is electrically insulated by the coupler 16. The output of the load current monitor signal to the device 1 is performed via a photocoupler 22 which is an electrically insulating means.

The input circuit section 14A has input terminals S1, S2
, The transmitting side (light emitting diode) 16a of the triac coupler 16 connected to the power supply.

The output circuit section 14B is connected to the load power supply 9
Is supplied to the heater 3. The output circuit section 14B has a receiving side 16b of the triac coupler 16, a switching element (triac) 17, a snubber circuit 18 having a noise absorbing function, and a varistor 19 having a noise absorbing function. .

The receiving side 16b of the triac coupler 16, the switching element 17, the snubber circuit 18, and the varistor 1
Reference numeral 9 denotes wires 28A and 28B for output terminals T1 and T2.
Are connected in parallel through a triac coupler 1
The receiving side 16b of 6 supplies a gate current to the switching element 17. The switching element 17 and the output terminal T
1 is provided with a resistor 20 through which a load current flows.

Both ends of the resistor 20 are connected to the input side of the load current monitor circuit section 21. The output side of the load current monitor circuit section 21 is connected to output terminals U1 and U2 via a photocoupler 22. Connected. The output terminals U1 and U12 are connected to signal input terminals 31 and 32 of the temperature controller 1 via signal lines 29 and 30, respectively.
To be entered.

A power supply unit 25 for driving the load current monitor circuit unit 21 includes a transformer (DC-DC converter) 24 and a drive power supply 26. The primary coil of the transformer 24 is connected to a connection terminal. The secondary coil of the transformer 24 is connected to the input side of the drive power supply 26, and the output side of the drive power supply 26 is connected to the load current monitor circuit 21. Then, the connection terminals W1, W2
Is connected to an external power supply 27. Note that the DC-DC converter 24 is a device that converts a direct current into an alternating current, then steps down the voltage by a transformer and rectifies it to convert a direct current voltage.

The load current monitor circuit section 21 includes the resistor 2
It has a function of outputting the current detected at 0 as a load current monitor signal. For example, amplifying means (amplifying means for amplifying a load current detection signal detected by the resistor 20 and being a voltage across the resistor 20) A full-wave rectifier (not shown) for full-wave rectifying the load current detection signal (voltage) amplified by the amplifier, and a load current detection signal full-wave rectified by the full-wave rectifier. Amplifying means (not shown) for greatly amplifying the (voltage), and a comparator (not shown) for forming a square wave by thresholding the waveform of the load current detection signal (voltage) amplified by the amplifying means. ing.

Therefore, the load current a shown in FIG. 3 (2) flows through the resistor 20, and the voltage across the resistor 20 is extracted as the load current detection signal b shown in FIG. 3 (3). In this case, the load current a is supplied to the plurality of heaters 3 arranged in parallel, and one of the heaters 3 breaks down, the current value decreases, and the waveform changes.

After the load current detection signal b is amplified by the amplifying means, it is full-wave rectified by the full-wave rectifying means and amplified by the amplifying means as shown in FIG.
Then, the waveform of the amplified load current detection signal (voltage) is thresholded by a comparator, shaped into a square wave as a comparison voltage shown in (5) of FIG. 3, and has a pulse width corresponding to the magnitude of the load current. Is output as a changing load current monitor signal. The signal shown in (6) of FIG. 3 is a smoothed load current monitor signal.

In the solid-state relay 2 described above, the output circuit section 14 B uses the triac coupler 16 to control the temperature controller 1 on the control device side and the load power supply 9.
The side is electrically insulated.

In the load current monitor circuit section 21,
Since the resistor 20 is built in the wiring 28A side of the output circuit section 14 in series with the switching element 17 with respect to the output terminal T1, the load current monitor circuit section 21 and the temperature on the control device side are connected. The controller 1 must be electrically insulated. For this purpose, a photocoupler 22 is used on the output side of the load current monitor circuit section 21, and a transformer 24 is incorporated in a power supply system of a power supply section 25 of the load current monitor circuit section 21. I have.

Therefore, the temperature controller 1 on the control device side is reliably electrically insulated from the load power supply 9 by the triac coupler 16, the photo coupler 22, and the transformer 24 as described above, Even if a person touches the controller 1, safety is ensured so as not to cause an electric shock.

Next, the operation of the temperature control device using the solid state relay 2 configured as described above will be described.

First, the temperature control is started, and the temperature controller 1
The CPU 8 outputs a control signal i, which is input to the transmission side of the triac coupler 16 of the solid state relay 2 and is converted into an optical signal by the light emitting diode 16a emitting light, which is then received by the triac coupler 16. Side 1
6b, a gate current is supplied from the receiving side 6b to the switching element 17, and the switching element 17 operates to supply a load current to the heater 3, and the heater 3 generates heat to heat the control target 4.

In the output circuit section 14B, the current supply state at that time is detected by the resistor 20. Further, the CPU 8 controls the solid state relay 2 so that the current temperature detected by the temperature sensor 5 becomes the target temperature set by the setting unit 6.

The load current monitor circuit 21 is connected to the CPU 8 of the temperature controller 1 and monitors energization by the resistor 20. The monitor current is transmitted to the CPU 8 to determine whether the heater 3 is broken or disconnected. The presence or absence of monitor current,
When the square wave of the monitor current changes, the CPU 8 determines that the heater 3 has been disconnected, displays that fact on the display unit 7, and outputs an alarm from the alarm output unit 29A.

In this case, the load current monitor circuit 21
Outputs the load current monitor signal as the load current monitor signal b whose pulse width changes in accordance with the magnitude of the load current a before smoothing as described above.

The load current monitor signal is converted into an optical signal by the photocoupler 22 and output to the output terminal U.
1, temperature controller 1 from U12 via signal lines 29, 30
Input to the CPU 8 through the signal input terminals 31 and 32 of
A disconnection or the like is detected from a change in the pulse width of the load current monitor signal or the like.

In the solid state relay 2, the triac 17, the snubber circuit 18, and the varistor 19
It is also possible to form a module in which the resistor 20 and the resistor 20 are configured as one unit.

A photo coupler may be used instead of the triac coupler 16 or a transformer (DC-DC
Instead of the converter 24, a photovoltage coupler combining a light emitting diode and a solar cell may be used.

The load current monitor signal output from the output side of the load current monitor circuit 21 is output to an output terminal U.
1, temperature controller 1 from U12 via signal lines 29, 30
Are connected to the signal input terminals 31 and 32 of the CPU and input to the CPU 8, but the output terminals U1 and U12 are connected to the ammeter or the PL.
C (both not shown) may be connected to monitor the energization.

Although the load current monitor circuit 21 outputs the monitor signal indicating the presence or absence of the load current, the monitor signal may be output as an analog signal depending on the magnitude of the load current. .

Further, a transformer (DC-DC converter) 2
4, the primary coil was connected to the power supply connection terminals W1 and W2, and the external power supply 8 was connected to the power supply connection terminals W1 and W2 to secure the power supply of the load current monitor circuit unit 21. The power supply connection terminals W1 and W2 may be connected to the internal power supply of the temperature controller 1 which is a control device.

According to the first embodiment of the present invention described above,
Solid state relay 2 is a triac coupler 16
Thus, the temperature controller 1 on the control device side and the load power supply 9 side can be insulated, and in the load current monitoring circuit section 21, the resistor 20 is incorporated in the output circuit section 14. For this reason, it is necessary to electrically insulate the load current monitor circuit section 21 from the temperature controller 1 on the control device side. Is used, and
A transformer (DC-DC converter) 24 is incorporated in a power supply unit 25 of the load current monitor circuit unit 21. The temperature controller 1 on the control device side includes a triac coupler 15, a photo coupler 22, and a transformer. (DC-DC converter) 24 reliably and electrically insulates from the load power supply 9 side, so that even if a person touches the temperature controller 1, safety can be secured so as not to receive an electric shock.

Further, as shown in FIG. 4, power supply to the load current monitor circuit section 21 may be performed by voltage supply from the load power supply 9 side. In this case, the load power supply 9 is connected to the input side of the drive power supply 26 via the terminals T1 and T3, and the output side of the drive power supply 26 is connected to the load current monitor circuit 21.

(Embodiment 2) FIG. 5 shows Embodiment 2 of the solid state relay according to the present invention.

The solid state relay 2 according to the present invention
1 has a failure detection function such as ON failure detection and disconnection detection of the switching element 17. That is, the solid state relay 2-1 has an input circuit section 41A for receiving a control signal from a temperature controller 40 as a control device, a switching element 17 for opening and closing a load current, and an output terminal on the load power supply 9 side. An output circuit unit 41B connected via T1 and T2,
It has a resistor 42 provided between the switching element 17 and the output terminal T1 and through which a load current flows, and a failure detection circuit 43. The failure detection circuit 43 is connected to the input side of the control signal A. And a load current detection signal B input side and a failure detection signal C output side. The input circuit section 41A and the output circuit section 41B are the same as those of the first embodiment of the present invention.
And the resistor 42 is incorporated in the output circuit 41B in the same manner as the resistor 20.

The input side of the control signal A in the failure detection circuit section 43 is connected to the input circuit section 41A via a photocoupler 44 which is an electrical insulating means. The input side of the signal B is connected to both ends of a resistor 42 incorporated in the output circuit section 41B. Further, the output side of the failure detection signal C in the failure detection circuit section 43 is connected to output terminals U1 and U2 via a photo coupler 45 which is an electrical insulating means. The output terminals U1 and U12 are connected to a controller 48 via signal lines 46 and 47.

A power supply 49 for driving the failure detection circuit 43 includes a transformer (DC-DC converter) 50 as an electrically insulating means and a drive power supply 51.
The primary coil of the transformer 50 is connected to the connection terminals W1 and W2, the secondary coil of the transformer 50 is connected to the input side of the drive power supply 51, and the output side of the drive power supply 51 is a failure detection circuit. It is connected to the unit 43. And the connection terminal W1,
An external power supply 52 is connected to W2.

In the solid-state relay 2-1 described above, in the output circuit section 41B, the temperature controller 1 on the control device side and the load power supply 9 side are electrically insulated by the triac coupler 16.

Further, in the failure detection circuit 43, the resistor 42 is connected to the output terminal T1 in series with the switching element 17 on the side of the wiring 28A of the output circuit 41B. It is necessary to electrically insulate the detection circuit 43 from the temperature controller 1 on the control device side. For this purpose, a photo-coupler 44 is used on the input side of the control signal A of the failure detection circuit 43, and the failure detection circuit 43
A photocoupler 45 is used on the output side of the power supply unit, and a transformer 50 is incorporated in a power supply unit 49 of the failure detection circuit unit 43.

Therefore, the temperature controller 1 on the control device side uses the triac coupler 16, the photocouplers 44 and 45, and the transformer 50 to load the power supply 9 as described above.
It is securely electrically insulated from the side, and safety is ensured so that even if a person touches the temperature controller 1 and the controller 48, an electric shock will not occur.

First, the temperature control is started, and the temperature controller 1
Of the solid state relay 2-1 outputs the control signal i.
6 and is converted into an optical signal by the light emission of the light emitting diode 16a and transmitted to the receiving side 16b of the triac coupler 16, and a gate current is supplied to the switching element 17 from the receiving side 6b. 17 operates to supply a load current to the heater 3, and the heater 3 generates heat to control the object 4.
Heat.

In the output circuit section 41B, the energized state at that time is detected by the resistor 42. The CPU 8 controls the solid state relay 2 so that the current temperature detected by the temperature sensor 5 becomes the target temperature set by the setting unit 6.
Control 1

The failure detection circuit 43 includes an input circuit 41
A control signal A is input from the A side, and the output circuit 41
A load current detection signal B, which is a voltage at both ends of the resistor 42, is input from the B side, the control signal A is compared with the load current detection signal B, and a failure detection signal C is output. For example, if there is a control signal A and there is no load current detection signal B, it is an open failure (disconnection), and if there is no control signal A and there is a load current detection signal B, the temperature controller 1 side Failure, these failure detection signals c are output,
It is transmitted to the controller 48 as an alarm signal d.

The solid state relay terminal 2-2 according to the present invention, as shown in FIG. 6, replaces the solid state relay 2 described above with a plurality of controlled objects 4-1, 4-2,.
.. A plurality of input circuit sections 14A, an output circuit section 14B, and a plurality of load current monitor circuit sections 12 so as to correspond to a large number of heaters 3 for heating 4-n, and power is supplied to these load current monitor circuit sections 12 The input circuit unit 14A, the output circuit unit 14B, and the plurality of load current monitoring circuit units 12 are configured as one unit.

That is, the solid state relay 2
An output circuit having an input circuit section 14A for receiving a control signal from the temperature controller 1 which is a control device, and a switching element 17 for switching a load current, and connected to the load power supply 9 via output terminals T1 and T2. A resistor 20 provided between the switch 14B and the switching element 17 and the output terminal T1 and through which a load current flows.
And a load current monitor circuit section 21 for processing the voltage at the resistor 20 and outputting it as a load current monitor signal to the temperature controller 1. The input circuit section 14A and the output circuit section 14B are electrically connected. Triac
The power is supplied to the load current monitor circuit section 21 via a transformer 24 which is an electrically insulating means, and is electrically insulated by the coupler 16. The output of the load current monitor signal to the device 1 is performed via a photocoupler 22 which is an electrically insulating means.

Therefore, the controlled objects 4-1, 4-2,.
.. A 4-n temperature control system can be constructed. For this purpose, the controlled objects 4-1, 4-2,.
It is not necessary for the user to install a CT sensor for every n heaters 3, so that the number of assembling steps can be reduced and the installation space can be reduced.

In particular, it is possible to omit a complicated operation process required for a user to pass or wind an electric wire as a primary penetration wire through a CT sensor, which is necessary when assembling the apparatus.

[0065]

As described above, according to the solid state relay of the present invention, the power supply to the load current monitor circuit section and the output of the load current monitor signal from the load current monitor circuit section are electrically isolated. The control device side and the load power supply side can be reliably insulated by this electrical insulating means, and even if a control device, for example, a temperature controller is touched by a person, an electric shock can be prevented. Safety can be ensured not to.

Further, it is not necessary for the user to install the CT sensor of the current detecting unit on the heater or the like to be controlled,
The number of assembly steps can be reduced, and the installation space can be reduced. The user has to perform complicated work such as passing or winding an electric wire as a primary penetration wire through a CT sensor when assembling the device. The process can be omitted.

According to the solid state relay of the present invention, the power supply to the failure detection circuit, the input of the control signal from the input circuit, and the output of the failure detection signal from the failure detection circuit are electrically insulated. By performing through the means, by this electrical insulation means, it is possible to reliably insulate the control device side and the load power supply side, even if a control device, for example, a temperature controller is touched by a person, Safety can be ensured to prevent electric shock.

Further, it is not necessary for the user to install the CT sensor of the current detection unit on the heater or the like to be controlled.
The number of assembly steps can be reduced, and the installation space can be reduced. The user has to perform complicated work such as passing or winding an electric wire as a primary penetration wire through a CT sensor when assembling the device. The process can be omitted.

According to the solid state relay terminal of the present invention, in the solid state relay, the power supply to the load current monitor circuit section and the output of the load current monitor signal from the load current monitor circuit section are electrically isolated. The control device side and the load power supply side can be reliably insulated by this electrical insulating means, and even if a control device, for example, a temperature controller is touched by a person, an electric shock can be prevented. Safety can be ensured not to.

Further, it is not necessary for the user to install the CT sensor of the current detection unit on the heater to be controlled, so that the number of assembling steps can be reduced, and the installation space can be reduced. It is possible to omit a complicated operation process required for a user to pass or wind an electric wire as a primary penetration wire through a CT sensor when assembling the apparatus.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of a solid state relay according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the configuration of a temperature controller.

FIG. 3 is a signal processing waveform diagram in a load current monitor circuit unit.

FIG. 4 is a configuration explanatory view of a modified example of the solid state relay according to the present invention.

FIG. 5 is a configuration explanatory diagram of a solid state relay according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a configuration of a solid state relay terminal according to the present invention.

FIG. 7 is an explanatory diagram of wiring of a CT sensor in a conventional temperature control device.

FIGS. 8 (1) to (5) are explanatory diagrams of a wiring method in a CT sensor.

FIG. 9 is a configuration explanatory view of a conventional temperature control device using a solid state relay.

FIG. 10 is a configuration explanatory view of a conventional temperature control device using another solid state relay.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Temperature controller (control apparatus) 2 Solid state relay 2-1 Solid state relay 2-2 Solid state relay terminal 3 Heater (heating means) 4 Control object 5 Temperature sensor 6 Setting part 7 Display part 8 CPU 9 Load power supply 14A Input Circuit section 14B Output circuit section 16 Triac coupler (electrical insulation means) 16a Transmitting side (light emitting diode) 16b Receiving side 17 Switching element (triac) 18 Snubber circuit 19 Varistor 20 Resistor 21 Load current monitor circuit section 22 Photo coupler (Electrical insulating means) 24 Transformer (DC-DC converter) (Electrical insulating means) 25 Power supply unit 26 Drive power supply 27 External power supply 28A Wiring 28B Wiring 29A Alarm output unit 29 Signal line 30 Signal line 40 Temperature controller (Control) Equipment) 41A Input circuit 41B Output circuit part 42 Resistor 43 Failure detection circuit part 44 Photocoupler (electrical insulation means) 45 Photocoupler (electrical insulation means) 46 Signal line 47 Signal line 48 Controller 49 Power supply part 50 Transformer (DC-DC converter) ) (Electrical insulation means) 51 drive power supply 52 external power supply a load current b load current detection signal a control signal b load current detection signal c failure detection signal d alarm signal

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (6)

[Claims] An input circuit for receiving a signal from a control device; an output circuit having a switching element for opening and closing a load current and connected to a load power supply via an output terminal; A solid state relay in which a circuit unit and the output circuit unit are electrically insulated, and a resistor provided between the switching element and the output terminal and through which the load current flows; and A load current monitor circuit section that processes the voltage of the load current and outputs the load current monitor signal to the control device side; and a power supply section that drives the load current monitor circuit section. A solid-state relay, wherein the power supply of the power supply and the output of the load current monitor signal from the load current monitor circuit section are performed via an electrical insulating means. 2. An input circuit comprising: an input circuit for receiving a signal from a control device; and an output circuit having an open / close element for opening / closing a load current and connected to a load power supply via an output terminal. A solid state relay in which a circuit section and the output circuit section are electrically insulated, wherein a resistor provided between the switching element and the output terminal and through which the load current flows, and the input circuit section A failure detection circuit unit that outputs a failure detection signal by comparing a control signal from the controller with a load current detection signal from the resistor side; and a power supply unit for driving the failure detection circuit unit. Wherein the power supply to the unit, the input of the control signal from the input circuit unit, and the output of the failure detection signal from the failure detection circuit unit are performed via an electrical insulating means. Tate relay. 3. The method according to claim 2, wherein the electrical insulation means comprises a triac.
The solid state relay according to claim 1, wherein the relay is a coupler, a photo coupler, or a transformer. 4. The solid state relay according to claim 1, wherein the power supply to the load current monitoring circuit is performed by a voltage supply from a load side. 5. The method according to claim 1, wherein the load current monitor signal output from the load current monitor circuit is processed in a state before smoothing, and is output in a state in which a pulse width changes according to the magnitude of the load current. The solid state relay according to claim 1, claim 3, or claim 4. 6. A solid state relay having an input circuit for receiving a signal from a control device, a switching element electrically insulated from the input circuit and for opening and closing a load current, and an output terminal on a load power supply side. An output circuit unit connected through the switch, a resistor provided between the switching element and the output terminal and through which the load current flows, and processing a voltage at the resistor to load the control device with a load. A load current monitor circuit that outputs a current monitor signal; and a power supply unit that drives the load current monitor circuit. Power is supplied to the load current monitor circuit and power is supplied from the load current monitor circuit. The output of the load current monitor signal is performed via an electrical insulating means, and a plurality of the solid state relays are connected. Good state relay terminal.