JPH0321080Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is a three-phase solid state relay (hereinafter referred to as three-phase
(denoted as SSR).

[Prior art] Conventionally, when controlling the drive of a three-phase AC motor, an electromagnetic switch, which is a mechanical relay, is used to control the opening and closing of the electromagnetic switch to control the supply of three-phase AC power to the motor. I was trying to do that. However, this electromagnetic switch has a problem in that under usage conditions where the electromagnetic switch is frequently opened and closed, its contacts become severely worn, resulting in a shortened lifespan.

By the way, conventional single-phase solid-state relays (hereinafter referred to as single-phase SSR) using semiconductors have been used to control the supply of single-phase AC power to loads. does not require a contact like the electromagnetic switch described above, and therefore there is no problem of shortened life due to wear of the contact.

FIG. 1 shows such a single-phase SSR semiconductor main element circuit 80. In the figure, 81 and 82 are power supply side and load side main terminals, 83 and 84 are first and second thyristors, and 85 and 86 are main terminals on the load side. Control terminals 87 and 88 connected to a control circuit (not shown) are resistors 8 and 88, respectively.
9. First and second gate auxiliary circuits each consisting of a diode 90.

When the control signal externally applied to the control circuit is "H", the control terminals 85, 86
As a result, in the positive half cycle of single-phase AC, the power supply side main terminal 81, the first gate auxiliary circuit 87, between the control terminals 85 and 86, the gate of the second thyristor 84, and the load side main terminal 82. An auxiliary current flows through the path, turning on the second thyristor 84,
As a result, the main current flows from the power supply side main terminal 81 through the second thyristor 84 to the load side main terminal 82,
Similarly, in the negative half cycle of single-phase AC, the second gate auxiliary circuit 88 and the first thyristor 83
operates, and the main current flows from the load side to the first thyristor 8.
3 to the power supply side, and as a result, single-phase power is supplied to the load.

On the other hand, when the control signal is "L", the control terminals 85 and 86 are in an open state, and as a result, both thyristors 83 and 84 remain off, and single-phase power is not supplied to the load. Therefore, if this single-phase SSR is used, the supply of single-phase power to the load can be controlled to be connected or disconnected using the control signal.

In such a conventional situation, when controlling the supply of the three-phase AC power to the load, the problem of shortened life can be avoided by combining the single-phase SSR instead of the electromagnetic switch. It is considered possible to do so.

Here, the single-phase SSR includes the main element circuit 80.
An absorber circuit is provided together with the control circuit and the main element circuit 80, so that when surge voltage such as lightning is applied between the main terminals 81 and 82, the surge voltage is absorbed and the main element circuit 80 is protected. Therefore, when a three-phase SSR is configured by combining single-phase SSRs as described above, the above-mentioned absorber circuits are also provided for each phase, but an insulation distance is required between adjacent absorber circuits, and this insulation distance is If enough space is taken, the entire device will become very large.

[Summary of the idea]

In view of these points, the present invention avoids the problem of shortened service life due to wear of the contacts in the electromagnetic switch, and furthermore, the device can be made compact, and the assembly work is easy without increasing the number of manufacturing steps.
The purpose is to provide SSR.

That is, the present invention is a three-phase SSR equipped with three semiconductor main element circuits for connecting and disconnecting the supply of three-phase AC power to a load, and each absorber circuit is provided in the absorber section of the three-phase SSR. In addition to providing a comb-shaped barrier with a cutout in the center to separate the
Three absorber circuits are mounted on a single printed circuit board in which a cut is formed in a portion corresponding to the barrier.

[Example of idea]

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Figures 2 to 6 are three-phase diagrams according to an embodiment of the present invention.
The SSR is shown in Fig. 2, where 1 is a 3-phase AC power supply, 2 is a 3-phase AC motor that is a load, and 3 is the above 3-phase AC power supply.
A three-phase cable 4 connects the phase alternating current power supply 1 and the motor 2, and 4 is a three-phase SSR inserted in the middle of the three-phase cable 3.

Figures 3 to 6 show the three-phase SSR 4 and its absorber section in detail. 11, 12, and 13 are main terminals of this SSR main body 10, 20 is an input terminal of a control circuit (not shown) that controls the main element circuit 80 on and off according to an external control signal, and 30 is the main element circuit 80
This is an absorber section that protects the motor from surge voltage.

In the absorber section 30, 31 is an absorber case, 32, 33, and 34 are absorber circuits each consisting of a resistor 35, a varistor 36, and a capacitor 37, and 38, 39 are for separating the absorber circuits 32 to 34 of each phase. The barrier has a notch in the center and is formed integrally with the absorber case 31. Reference numeral 40 denotes a printed circuit board on which the absorber circuits 32 to 34 of each phase are mounted, and on the printed circuit board 40, as shown in FIG. Circuits 32-34
A resistor 35, a varistor 36, and a capacitor 37 constituting the circuit are mounted for each phase, and are connected to the wiring pattern of each phase. Also, 40a, 40b
are cutout grooves formed to match the shapes of the barriers 38 and 39, respectively. Note 41, 42,
43 is an output terminal of each of the above-mentioned absorber circuits 32-34.

In the device of this embodiment, a 3-phase SSR using a semiconductor is configured to control the supply of 3-phase AC power to the load, so even under usage conditions where switching is performed frequently. Sufficient durability,
You can get longevity. In addition, in the absorber section 30 of such a three-phase SSR, barriers 38 and 39 are provided in the case 31 to connect each absorber circuit 32 to 3.
4, the gap between each absorber circuit 32 to 34 can be made smaller.
The device can be made smaller. Moreover, at that time,
Since the barriers 38 and 39 are formed by cutting out the central portions, only one printed circuit board 40 is required for mounting the three absorber circuits 32 to 34.
Compared to the case where no barrier is provided at all, the number of manufacturing steps does not increase and the assembly work does not become complicated.

[Effect of idea]

As described above, according to the present invention, the connection and disconnection of the supply of three-phase AC power to the load can be performed using a three-phase
Since the SSR is used, it has sufficient durability and service life even under conditions of frequent opening and closing, and the absorber section of the 3-phase SSR has a central section to separate each absorber circuit. In addition to providing a comb-shaped barrier with a notch, the three absorber circuits are mounted on a single printed circuit board with a notch formed in the portion corresponding to the barrier, so the device can be made smaller. Furthermore, there is an effect that the assembly work is simple without increasing the number of manufacturing steps.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of the semiconductor main element circuit of a single-phase SSR, Figure 2 is a diagram showing the state of use of a three-phase SSR according to an embodiment of the present invention, and Figures 3a and b are respectively diagrams of the above-mentioned three-phase SSR. The plan view, its front view, and Figure 4 are in accordance with 3.
FIG. 5 is a diagram showing the wiring pattern of the printed circuit board of the absorber section, and FIG. 6 is a perspective view of the absorber case of the absorber section. 1... 3-phase AC power supply, 2... Motor (load),
30...Absorber section, 31...Absorber case, 32, 33, 34...Absorber circuit, 3
8, 39... Barrier, 80... Semiconductor main element circuit. In the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims for Utility Model Registration] A three-phase solenoid system comprising three semiconductor main element circuits that disconnect and disconnect the supply of three-phase AC power to a load, and an absorber section that protects the semiconductor main element circuits from abnormally high voltages. The absorber section is a two-state relay, and the absorber section includes an absorber case and three absorber circuits provided for each of the semiconductor main element circuits housed in the absorber case. A comb-shaped barrier with a cutout in the center is provided to separate the absorber circuits in each layer, and the three absorber circuits are mounted on a single printed circuit board with a cutout in the part corresponding to the barrier. A three-phase solid-state relay characterized by: