JPS585430Y2 - solid state relay - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid state relay that supplies load current by turning on a load current control means such as a triac in response to an input signal for use.

FIG. 1 shows a schematic circuit diagram of a conventional example.

The input circuit 1 receives a predetermined signal from a signal generating means such as a proximity switch, a microswitch, and a photoelectric switch.

This signal is transmitted to the switching circuit 2, and a preferred transmitting means is a converter, etc.

The switching circuit 2 performs a switching operation in response to the predetermined signal, and makes the rectification side terminals 03 and 04 of the full-wave rectifier 3 conductive or non-conductive.

When the rectifying side terminals 03 and 04 of the full-wave rectifier 3 are electrically connected, a current flows to the control terminal (gate terminal) of the triac 4 (/''), which is a load current control means, and the triacs 1 to 4 are electrically conductive (turn on).

A predetermined load and a power supply are connected in series between both output terminals 01 and 02 of the triac 4, and load current is supplied when the triac 4 is turned on.

The resistor 5 is for protecting the gate of the l/liak 4.

The resistor 6 and the capacitor 7 absorb surges that occur when a coil or the like is used as a load.
This is to protect the triac 4 and prevent malfunction.

Therefore, at least two resistors 5 and 6 are required to protect the triac, which requires time and effort to assemble, and increases heat generation (energy loss) inside the circuit.

The present invention has been made in view of the above circumstances, and aims to provide a solid state relay that can improve the efficiency of assembly work and reduce the number of parts by simplifying the circuit configuration.

A preferred embodiment of the present invention will be described in detail below with reference to FIG.

The input circuit 11 is connected to a device that generates a predetermined signal, such as a proximity switch, a charging switch, a non-contact microswitch, etc., and a device in which an amplifier circuit or the like is added to these switches as necessary.

Predetermined signal outputs generated by these devices are transmitted to the electrically isolated switching circuit 12 via a photocoupler or the like.

The switching circuit 12 is turned on or off in response to the predetermined signal.
It performs an OFF switching operation to control conduction and non-conduction between the rectification side terminals 03 and 04 of the full-wave rectifier 13.

Depending on whether the full-wave rectifier 13 is turned on or off, the gate current of the triac 14, which is a switching means for controlling the load current, is controlled to be turned on or off, and the triac 14 is turned on or off.

A series connection circuit including a resistor 16 and a capacitor 17 is connected between both output terminals 01 and 02 of the triac 14, which is a switching means for controlling the load current.

A connection point between the resistor 16 and the capacitor 17 is connected to one AC side terminal 05 of the full-wave rectifier 13.

The other AC side terminal 06 is connected to the control terminal, ie, the gate terminal, of the triac 14.

Note that a series connection circuit (not shown) of a predetermined load and a power source is connected between the output terminals 01 and 02.

Now, during the turn-on operation of the triac 14,
The gate current of the triac 14 flows through the resistor 16,
This resistor 16 suppresses the gate current of the triac 14 and provides gate protection.

When a surge voltage or the like is applied between the output terminals 01 and 02, the surge is absorbed by the resistor 16 and the capacitor 17, thereby preventing the triac 14 from malfunctioning.

As is clear from the above description, in the solid state relay according to the present invention, the resistor 16 protects the gate of the triac 14 and prevents malfunctions, so the circuit configuration is simple and the number of parts can be reduced.

Also, since the resistance is low, heat generation (energy loss) in the circuit can be reduced.

Note that the present invention is not limited to the above-mentioned embodiments. For example, when connecting a DC power source between output terminals 01 and 02, the load current control means may include a SIRISK, a power transistor, etc. in addition to a TRIAC. Various high current switching means can be used.

Various configurations of this kind are possible without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic circuit diagram showing a conventional example, and FIG. 2 is a schematic circuit diagram showing an embodiment of a solid state relay according to the present invention. 1.11...Input circuit, 2,12...
Switching circuit, 3.13...Full wave rectifier,
4,14...triac, 5,6゜16...
...Resistor, 7,17...Capacitor.

Claims (1)

[Scope of utility model registration request] A switching circuit that turns on and off according to the input of an input signal, conduction and non-conduction are controlled according to the on and off operations of this switching circuit, and a load and a power source are connected in series between both output terminals. It consists of a load current control switching means, and a series connection circuit of a resistor and a capacitor connected between both output terminals of the load current control switching means, and the control terminal of the load current control switching means is connected between the resistor and the capacitor. A solid state relay characterized by being connected to the connection point of