CN216721295U

CN216721295U - Solid-state relay circuit adopting direct-current optocoupler

Info

Publication number: CN216721295U
Application number: CN202123109309.9U
Authority: CN
Inventors: 范结义; 李云孝
Original assignee: Xiamen Yunsheng Precision Electronics Co ltd
Current assignee: Xiamen Yunsheng Precision Electronics Co ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-06-10
Anticipated expiration: 2031-12-10

Abstract

The utility model discloses a solid-state relay circuit adopting a direct-current optocoupler, which comprises a direct-current optocoupler, a bidirectional thyristor, a first resistor, a second resistor and a bias power supply, wherein the direct-current optocoupler is connected with the first resistor; the direct current optocoupler comprises a light emitting tube and a phototriode, the light emitting tube and a first resistor are connected between two input ends of the solid-state relay in series, and an emitting electrode of the phototriode is connected with a first end of the bias power supply; the collector of the phototriode is connected to the control end of the bidirectional triode thyristor through a second resistor; the second end of the bias power supply is connected with the first terminal of the bidirectional controllable silicon; and the first terminal and the second terminal of the bidirectional controllable silicon are respectively connected with the two output ends of the solid-state relay. The circuit realizes that the bidirectional silicon controlled rectifier device is driven by the direct current optocoupler by constructing a bias power supply, thereby realizing the cost optimization of the solid-state relay.

Description

Solid-state relay circuit adopting direct-current optocoupler

Technical Field

The utility model relates to the field of solid-state relays, in particular to a solid-state relay circuit adopting a direct-current optocoupler.

Background

In the solid-state relay commonly used in the market, the used optocoupler is basically an alternating current optocoupler, the cost of the alternating current optocoupler is more expensive than that of the direct current optocoupler, and the cost of the alternating current optocoupler is 0.5-0.8 yuan more expensive than that of the direct current optocoupler. When a plurality of solid-state relays are needed on the control panel, if a direct-current optocoupler can be adopted, obvious cost optimization can be realized.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a solid-state relay circuit using a dc optical coupler, so as to reduce the cost of the solid-state relay.

In order to achieve the above object, the present invention provides a solid-state relay circuit using a dc optical coupler, comprising a dc optical coupler, a bidirectional thyristor, a first resistor, a second resistor and a bias power supply;

the direct current optocoupler comprises a light emitting tube and a phototriode, the light emitting tube and a first resistor are connected between two input ends of the solid-state relay in series, and an emitting electrode of the phototriode is connected with a first end of the bias power supply; the collector of the phototriode is connected to the control end of the bidirectional triode thyristor through a second resistor;

the second end of the bias power supply is connected with the first terminal of the bidirectional controllable silicon;

and the first terminal and the second terminal of the bidirectional controllable silicon are respectively connected with the two output ends of the solid-state relay.

Further, the solid state relay circuit further comprises a first capacitor, and the first capacitor is connected across the control end and the second terminal of the bidirectional controllable silicon.

Further, the bias power supply comprises a transformer, the transformer comprises a primary coil and a secondary coil, two ends of the secondary coil are respectively connected to the first end and the second end of the bias power supply, and the primary coil is used for accessing an external control signal.

Further, the bias power supply includes: the second capacitor, the third resistor, the first diode and the third end; the second capacitor is connected between the first end and the second end of the bias power supply in a bridging mode; the third resistor is connected in series with the first diode and bridged between the first end and the third end of the bias power supply, and the conduction direction of the first diode is as follows: from the first terminal to the third terminal of the bias power supply;

and the third terminal of the bias power supply is connected with the second terminal of the bidirectional controllable silicon.

Still further, the bias power supply further comprises a fourth resistor and/or a first voltage clamp protection device; the fourth resistor and/or the first voltage clamp protection device is connected across the first end and the second end of the bias power supply.

The utility model realizes the following technical effects:

the circuit realizes that the bidirectional silicon controlled rectifier device is driven by the direct current optocoupler by constructing a bias power supply, thereby realizing the cost optimization of the solid-state relay.

Drawings

FIG. 1 is a conceptual model of the present invention;

FIG. 2 is a circuit schematic of an embodiment of the present invention;

fig. 3 is a circuit schematic of another embodiment of the present invention.

Reference numerals:

U1-DC optical coupler; 103-an emitter; 104-a collector electrode;

q1-triac; 201-control end; 202-a first terminal; 203-a second terminal;

30-bias power supply; 301-a first end; 302-a second end; 303-a third terminal;

c1, C2, C3-capacitance; d1-clamp diode; d2-diode;

r2, R4, R5, R6-resistance; T1-Transformer.

Detailed Description

To further illustrate the various embodiments, the utility model provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the utility model and, together with the description, serve to explain the principles of the embodiments. Those skilled in the art will appreciate still other possible embodiments and advantages of the present invention with reference to these figures. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The utility model will now be further described with reference to the accompanying drawings and detailed description.

As shown in fig. 1, the present invention provides a circuit structure of a solid-state relay using a dc optocoupler, where the dc optocoupler U1 includes a light emitting tube at an input control end and a phototransistor at an output control end, where the phototransistor is of an NPN type, a collector 104 of the phototransistor is connected to a control end 201 of a triac Q1 through a resistor R2, an emitter 103 of the phototransistor is connected to a first end 301 of a bias power supply 30, and a second end 302 of the bias power supply 30 is connected to a first terminal 202 of the triac Q1. The bias supply 30 provides a voltage bias such that when the phototransistor is on, the bias supply 30 operates to provide a bias voltage between the triac Q1 and the first terminal 202 and the control terminal 201 of sufficient magnitude to drive the triac on.

In the present circuit, it is preferable that a capacitor C1 is further included, and a capacitor C1 is connected across the control terminal 201 and the second terminal 203 of the triac Q1.

Example 1:

in this embodiment, the bias power supply 30 is externally powered, the bias power supply 30 is composed of a transformer T1, a low voltage ac signal (e.g. 5V) is externally input to a primary side of the transformer T1, and two terminals of a secondary side of the transformer T1 are respectively connected to the second terminal 203 of the triac Q1 and the emitter 103 of the phototransistor of the dc optical coupler U1. Due to the low price of the small transformer, the low-voltage alternating current signal can be obtained through the secondary winding under the alternating current application environment, and the cost is not increased. Therefore, this mode can reduce the cost.

Example 2:

in the present embodiment, the bias power supply 30 adopts a self-power-on mode, and the bias power supply 30 is provided with a third terminal 303 to take power from the load circuit of the solid-state relay. The bias power supply 30 is composed of resistors R4, R5, R6, a capacitor C2, a clamping diode D1, a diode D2 and a capacitor C3, wherein C2 is a non-polar capacitor, C3 is a polar capacitor (such as an electrolytic capacitor), and the clamping diode D1, the resistor R4, the capacitor C2 and the capacitor C3 are connected in parallel between the first terminal 202 of the triac Q1 and the emitter 103 of the phototransistor of the dc optical coupler U1. The resistor R5, the resistor R6 and the diode D2 are connected in series and are arranged between the second terminal 203 of the bidirectional triode thyristor Q1 and the emitter electrode 103 of the phototriode of the direct current optocoupler U1, wherein the cathode of the diode D2 is connected to the third terminal 303 of the bias power supply and the second terminal 203 of the bidirectional thyristor Q1. The clamping diode D1 is a voltage clamping protection device such as a voltage regulator or a transient voltage suppressor. In this embodiment, all devices used in the bias power supply 30 circuit are low-value devices, and this way, the effect of reducing the cost can be achieved.

Because the phototriode drive has unidirectionality, after the direct current optocoupler U1 is adopted, the drive mode of the bidirectional thyristor Q1 is I, II quadrant drive, but is not I, III quadrant drive when the alternating current optocoupler is adopted. In conventional application, the bidirectional thyristor adopts more I-th quadrant driving modes, so that the work of the solid-state relay is not obviously influenced by the direct-current optocoupler, and the performance of the solid-state relay is not influenced.

While the utility model has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the utility model as defined by the appended claims.

Claims

1. A solid-state relay circuit adopting a direct-current optical coupler is characterized by comprising a direct-current optical coupler, a bidirectional thyristor, a first resistor, a second resistor and a bias power supply;

2. The solid state relay circuit of claim 1, further comprising a first capacitor connected across the control terminal and the second terminal of the triac.

3. The solid state relay circuit of claim 1, wherein the bias power supply comprises a transformer including a primary coil and a secondary coil, the secondary coil having two ends respectively connected to the first end and the second end of the bias power supply, the primary coil for receiving an external control signal.

4. The solid state relay circuit of claim 1, wherein the bias supply comprises: the second capacitor, the third resistor, the first diode and the third end;

the second capacitor is connected between the first end and the second end of the bias power supply in a bridging mode;

the third resistor is connected in series with the first diode and bridged between the first end and the third end of the bias power supply, and the conduction direction of the first diode is as follows: from the first terminal to the third terminal of the bias power supply;

5. The solid state relay circuit of claim 4, wherein the bias supply further comprises a fourth resistor and/or a first voltage clamp protection device;

the fourth resistor and/or the first voltage clamp protection device is connected across the first end and the second end of the bias power supply.