CN2735662Y

CN2735662Y - Solid state relay

Info

Publication number: CN2735662Y
Application number: CN 200420089510
Authority: CN
Inventors: 李云孝
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-08-14
Filing date: 2004-08-14
Publication date: 2005-10-19
Anticipated expiration: 2014-08-14

Abstract

The utility model relates to a solid state relay, which relates to a solid state relay, in particular to an alternating current output type solid state relay using a direct current output type photoelectric coupler driving switch element. The solid state relay is provided with an input circuit, an isolation circuit and a switch element. The input end of the input circuit is externally connected with the power supply. The input end of the isolation circuit is connected with the output end of the input circuit. The output end of the isolation circuit is connected with the input end of the triggering signal of the switch element. The other output end of the isolation circuit is externally connected with a bias power supply. The output end of the switch element is externally connected with a load. The output end of the switch element is externally connected with the connection point of an alternating current power supply and the end of the bias power supply. The solid state relay is provided with the switch element which controls the current flowing over the outer load conducting or breaking according to the control signal supplied by the input circuit. The direct current output type photoelectric coupler replaces the alternating current output type photoelectric coupler to realize to the driving control the switch element by the electricity of the bias power supply. The solid state relay is stable in driving performance and low in cost and is provided with an over current protecting element and a voltage exponent rising restraint element in addition.

Description

Solid-state relay

Technical field

The utility model relates to a kind of solid-state relay (SSR), especially a kind of interchange output type solid-state relay that uses direct current output type photoelectrical coupler driving switch element, particularly, realize that direct current output type photoelectrical coupler replaces interchange output type photoelectrical coupler and finishes the solid-state relay that switch element is driven by one group of bias supply of stack on alternating voltage VAC.

Background technology

In existing interchange output type solid-state relay, the power supply of the driving element of switch element is from AC power VAC.Fig. 1 represents the major part structure chart of existing a kind of solid-state relay.In Fig. 1, solid-state relay comprises input circuit 2, photoelectrical coupler 6, resistor R 2, thyristor 7; Between input terminal I1, I2, apply DC power supply VDC (or AC power), and on lead-out terminal O1, O2, connect load LD, on load LD, apply AC power VAC.And load LD is made of resistor, motor etc.Input circuit 2 provides control signal for the light-emitting diode of photoelectrical coupler 6, and photoelectrical coupler 6 is made of light-emitting diode and two-way photoelectricity thyristor (controllable silicon).When from input circuit 2 supply control signals, lumination of light emitting diode, and make the photoelectricity thyristor that is subjected to light enter conducting state, in resistor R 2, R3, just there is alternating current to flow through.Thyristor 7 is made of bidirectional triode thyristor as switch element, when the voltage drop on the R3 reached the gate threshold voltage of thyristor 7, bidirectional triode thyristor entered conducting state, thereby made short circuit between lead-out terminal O1, O2, in load LD, there is alternating current to flow through, drives load LD.Otherwise if stop from the control signal of input circuit 2, then photoelectrical coupler 6 ends, and thyristor 7 also ends, then open a way between lead-out terminal O1, O2, thus alternating current is interrupted, stop the driving of load LD.

Exchange output type photoelectrical coupler (constituting) driving thyristor switch element because existing solid-state relay is to use, make that the cost of solid-state relay is high by light-emitting diode and two-way photoelectricity thyristor.Secondly, in existing solid-state relay circuit, because exchanging the power supply of output type photoelectrical coupler is from AC power VAC, therefore than being easier to suffer the connection of solid-state relay self or cut-off state changes and from the influence of disturbing on the electrical network, can cause the solid-state relay misoperation in the time of seriously.

In addition, confirmed in existing solid-state relay that driving element causes potential safety hazard owing to do not have overcurrent protection measure, solid-state relay often to burst the phenomenon generation.

Summary of the invention

The purpose of this utility model is to provide that a kind of cost is low, the solid-state relay of function admirable.

To achieve these goals, the utility model adopts by increasing bias supply, change the technical scheme of the supply power mode of driving element, have according to coming control flows to cross the conducting of external loading from the control signal of input circuit supply or ending the switch element of (non-conduction), direct current output type photoelectrical coupler relies on the power supply that alternating voltage VAC goes up one group of bias supply of stack, finishes the driving to switch element.

The utility model is provided with housing, is provided with circuit printing plate, input circuit, buffer circuit and switch element in the housing, and input circuit, buffer circuit and switch element are located on the printed circuit board (PCB); The input external power supply of input circuit, said power supply can be DC power supply or AC power; The output of the input termination input circuit of buffer circuit, the triggering signal input of one output termination switch element of buffer circuit, the external bias supply of another output of buffer circuit: an output external load of switch element, another output external AC power supply of switch element and the contact of bias supply one end.

Said buffer circuit is direct current output type photoelectrical coupler or triode output type photoelectrical coupler.

Output at buffer circuit can connect buffer amplifier circuit, to increase the drive current to switch element.Between the triggering signal input of buffer amplifier circuit and switch element, can be provided with overflow protecting element, the optional resistor of using of overflow protecting element, for example fusing resistor.Between switch element triggering signal input and external power supply and bias supply contact, can establish voltage index climbing (DV/DT) suppression element, the optional capacitor of using of voltage index climbing suppression element, for example ceramic disc capacitor.

The utlity model has according to the control signal of supplying with from input circuit come control flows cross external loading electric current conducting or by the switch element of (non-conduction), direct current output type photoelectrical coupler relies on the power supply of bias supply to replace and exchanges the drive controlling of output type photoelectrical coupler realization to switch element, thereby driveability is more stable, and reduces the cost of solid-state relay significantly.In addition, the utility model is provided with overflow protecting element and voltage index climbing DV/DT suppression element, thereby improves the ability of the proof voltage index climbing DV/DT of solid-state relay.

Description of drawings

Fig. 1 is the critical piece composition diagram of existing a kind of solid-state relay.

Fig. 2 is the circuit composition frame chart of the utility model embodiment.

The circuit of Fig. 3 the utility model embodiment is formed schematic diagram.

Embodiment

Following examples will be further described the utility model in conjunction with the accompanying drawings.

The utility model is by one group of bias supply of stack on alternating voltage VAC, for direct current output type photoelectrical coupler provides power supply, finishes to the conducting of switch element or by the control of (non-conduction) state, realizes the significantly reduction of solid-state relay cost thus.

As shown in Figure 2, solid-state relay 1 is provided with input circuit 2, photoelectrical coupler 3, buffer amplifier circuit 4, overflow protecting element FR1, switch element 5, the input external direct current power supply VDC1 (or AC power) of input circuit 2.One output external load of switch element 5, another output external AC power supply VAC and bias supply VDC2 one end tie point, the overflow protecting element or the buffer amplifier circuit of another termination solid-state relay of bias supply.

As shown in Figure 3, solid-state relay 1 is provided with input circuit 2, photoelectrical coupler 3, buffer amplifier circuit 4, overflow protecting element FR1, voltage index climbing suppression element C1 (ceramic disc capacitor), switch element 5, input terminal I1 and I2, lead-out terminal O1 and O2, bias terminal O2 and O3 (wherein bias terminal O2 and lead-out terminal O2 are shared).Input terminal I1, I2 are connected to outside DC power supply VDC1, and lead-out terminal O1, O2 are connected to external loading LD and AC power VAC, and bias terminal O2, O3 are connected to outside direct current biasing power vd C2.

Input circuit 2 provides control signal for the light-emitting diode of photoelectrical coupler 3; photoelectrical coupler 3 is made of light-emitting diode and phototriode; when from input circuit 2 supply control signals; lumination of light emitting diode; and make and be subjected to the phototriode of light to enter conducting state; make buffer amplifier circuit 4 also enter conducting state; power supply by bias supply VDC2; at overflow protecting element (fusing resistor) FR1; there is direct current to flow through in the trigger end (grid) of switch element (thyristor) 5; make switch element (thyristor) 5 enter conducting state; thereby make lead-out terminal O1; short circuit between O2 has alternating current to flow through in load LD, drives load LD.

On the contrary, if stop from the control signal of input circuit 2, then photoelectrical coupler 3 ends, and buffer amplifier circuit 4 ends, and thyristor 5 also ends, then open a way between lead-out terminal O1, O2, thus alternating current is interrupted, stop driving to load LD.

Wherein overflow protecting element (fusing resistor) FR1 has the overcurrent protection effect, and ceramic disc capacitor C1 is used to suppress the transient voltage between thyristor 5 grids and the other end, thereby improves the ability of the proof voltage index climbing of solid-state relay.

The utility model be provided with according to the control signal of supplying with from input circuit come control flows cross external loading electric current conducting or by the switch element of (non-conduction), direct current output type photoelectrical coupler relies on the power supply that alternating voltage VAC goes up one group of bias supply of stack, realizes the driving to switch element.Because drive current comes the bias supply of self-stabilization rather than relies on AC power VAC, makes driveability more reliable and more stable; The price of direct current output type photoelectrical coupler makes that far below exchanging the output type photoelectrical coupler solid-state relay cost is declined to a great extent.

Claims

1, solid-state relay, be provided with housing, be provided with circuit printing plate, input circuit, buffer circuit and switch element in the housing, input circuit, buffer circuit and switch element are located on the printed circuit board (PCB), the input external power supply of input circuit, the output that it is characterized in that the input termination input circuit of buffer circuit, the triggering signal input of an output termination switch element of buffer circuit, the external bias supply of another output of buffer circuit; One output external load of switch element, another output external AC power supply of switch element and the contact of bias supply one end.

2, solid-state relay as claimed in claim 1 is characterized in that said buffer circuit is direct current output type photoelectrical coupler or triode output type photoelectrical coupler.

3, solid-state relay as claimed in claim 1 is characterized in that the output termination buffer amplifier circuit at buffer circuit.

4, solid-state relay as claimed in claim 3 is characterized in that being provided with overflow protecting element between the triggering signal input of buffer amplifier circuit and switch element.

5, solid-state relay as claimed in claim 4 is characterized in that overflow protecting element selects fusing resistor for use.

6, solid-state relay as claimed in claim 1 is characterized in that establishing voltage index climbing suppression element between switch element input and external power supply and bias supply contact.

7, solid-state relay as claimed in claim 6 is characterized in that voltage index climbing suppression element selects ceramic disc capacitor for use.