High-frequency interference resistant solid-state relay

Abstract

The utility model provides a solid-state relay resistant to high-frequency interference. The solid-state relay comprises an input assembly, a power supply assembly, a trigger assembly and an output assembly. The input assembly is used for accessing a control power supply, and the power supply assembly is connected with the input assembly 100 and used for outputting a stable trigger power supply. The trigger assembly comprises a photoelectric coupler and shunting pieces connected in parallel to the two ends of a light-emitting piece of the photoelectric coupler, and the power supply assembly is connected with the light-emitting piece of the photoelectric coupler. The output assembly is connected to the light receiving part of the photoelectric coupler, the output assembly is further connected with the power supply and the load, and when the photoelectric coupler is switched on, the power supply supplies power to the load through the output assembly. The shunting member is connected in parallel with the two ends of the photoelectric coupler light-emitting member, thereby improving the triggering threshold, enhancing the anti-interference capability, and avoiding the false triggering. The photoelectric coupler is adopted to isolate input and output, so that the electrical safety is improved, and the influence of electromagnetic interference on output is reduced. A trigger threshold can be flexibly set by adjusting the resistance value of the shunting member to adapt to different interference environments.

Description

Technical Field

[0001] This utility model relates to the field of relay technology, and in particular to a solid-state relay that is resistant to high-frequency interference. Background Technology

[0002] Solid-state relays (SSRs), as contactless switching devices, are widely used in industrial control, power electronics, and other fields. They achieve electrical isolation between input and output through optocouplers (such as silicon controlled rectifier optocouplers), offering advantages such as fast response, long lifespan, and no mechanical wear. However, traditional solid-state relays exhibit significant reliability deficiencies in environments with strong electromagnetic interference (EMI).

[0003] Low trigger threshold is susceptible to interference: The typical trigger threshold is 2.8 to 3.0 mA / 3V. Under strong interference (such as when the frequency converter or high-power motor is running), external electromagnetic noise may reach or exceed this threshold, causing the output to malfunction (such as not being able to completely shut off).

[0004] Reliance on shielded cables and installation limitations: To avoid interference, traditional solutions require the use of shielded cables for control lines, and these lines must be kept away from interference sources such as frequency converters. This not only increases costs but also limits installation flexibility.

[0005] Insufficient high-frequency interference suppression: Traditional circuits lack effective high-frequency filtering design, which makes them prone to introducing noise during long-distance transmission and affecting the stability of control signals.

[0006] Existing improvement solutions attempt to enhance anti-interference capabilities by adding RC filters or adjusting the optocoupler drive current, but still have the following limitations: simply increasing the trigger current slightly (e.g., from 3mA to 4mA) is insufficient to cope with strong industrial interference environments; and the lack of systematic optimization of the input voltage regulation and filtering design may still result in false triggering in complex EMI environments. Utility Model Content

[0007] To address the aforementioned problems, the purpose of this invention is to provide a solid-state relay that resists high-frequency interference. By connecting a shunt in parallel across the input terminals of the optocoupler, the trigger threshold is increased, thereby enhancing the relay's anti-interference capability.

[0008] This utility model is achieved through the following technical solution:

[0009] A solid-state relay resistant to high-frequency interference, comprising:

[0010] Input component, used to connect to control power;

[0011] A power supply component, connected to the input component, is used to output a stable trigger power supply;

[0012] A triggering component, comprising an optocoupler and a shunt connected in parallel across the light-emitting element of the optocoupler; the power supply component is connected to the light-emitting element of the optocoupler;

[0013] The output component is connected to the light-receiving element of the optocoupler. The output component is also connected to the power supply and the load respectively. When the optocoupler is turned on, the power supply provides power to the load through the output component.

[0014] Furthermore, the input component includes an input terminal, a filter capacitor connected in parallel between the positive and negative terminals of the input terminal, and a diode connected in series between the input terminal and the power supply component; the anode of the diode is connected to the input terminal, and the end of the filter capacitor furthest from the diode is grounded.

[0015] Furthermore, the power supply component includes an NPN transistor connected to the input component, a Zener diode connected between the base of the NPN transistor and ground, and a bias resistor connected in parallel between the collector and base of the NPN transistor; the emitter of the NPN transistor is connected to the trigger component, and the collector of the NPN transistor is connected to the input component.

[0016] Furthermore, the power supply component also includes a current-limiting resistor connected in series between the bias resistor and the common node of the input component and the collector of the NPN transistor.

[0017] Furthermore, the shunt includes a first resistor.

[0018] Furthermore, the relay also includes an indicator component, which includes a light-emitting diode connected in series and then in parallel across the light-emitting element of the optocoupler and a current-limiting resistor, the other end of which is grounded.

[0019] Furthermore, the optocoupler is a bidirectional silicon controlled rectifier optocoupler.

[0020] Furthermore, the output component includes an output terminal, a first unidirectional thyristor and a second unidirectional thyristor connected in parallel between the positive and negative terminals of the output terminal; the first unidirectional thyristor and the second unidirectional thyristor are arranged in opposite directions, and the control terminals of the first unidirectional thyristor and the second unidirectional thyristor are connected to the output terminals of the optocoupler one-to-one; the anode and cathode of the second unidirectional thyristor are connected to the live wire and neutral wire of the power supply, respectively; an eighth resistor is connected in parallel between the control terminal of the first unidirectional thyristor and its cathode, and a fifth resistor is connected in parallel between the control terminal of the first unidirectional thyristor and its cathode.

[0021] Furthermore, at least one end of the light-receiving element of the optocoupler is connected in series with the control terminal of the first unidirectional thyristor or the second unidirectional thyristor, and a current-limiting resistor is connected in series.

[0022] Furthermore, the output component also includes a seventh resistor and a first capacitor connected in series and then in parallel between the positive and negative terminals of the output terminal.

[0023] Compared with the prior art, the technical solution of this utility model and its beneficial effects are as follows:

[0024] (1) This utility model, by connecting a shunt in parallel across the light-emitting element of the optocoupler, raises the trigger threshold of the traditional solid-state relay, greatly enhancing the relay's anti-interference capability in strong electromagnetic interference environments. This effectively avoids malfunctions caused by external electromagnetic noise, such as false triggering or incomplete shut-off, thereby improving the relay's reliability in complex industrial environments. Furthermore, by adjusting the resistance value of the shunt, the trigger threshold can be flexibly set, enabling the relay to adapt to the needs of different interference environments.

[0025] (2) The filter capacitor C2 in the input component of this utility model can suppress high-frequency noise interference, and the diode D1 plays the role of preventing reverse connection, further ensuring the safety and stability of the device.

[0026] (3) The output component of this utility model adopts a bidirectional thyristor optocoupler and a first unidirectional thyristor and a second unidirectional thyristor set in opposite directions. No matter how the plug is inserted into the socket, power can be supplied when the optocoupler is turned on, which improves the adaptability and versatility of the relay. Attached Figure Description

[0027] Figure 1 This is a circuit diagram of a solid-state relay that resists high-frequency interference, provided by an embodiment of this utility model.

[0028] Illustration:

[0029] Input component -100; Power supply component -200; Trigger component -300; Output component -400. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0031] See Figure 1A solid-state relay resistant to high-frequency interference includes an input component 100, a power supply component 200, a trigger component 300, and an output component 400. The input component 100 is used to connect to a control power supply. The power supply component 200 is connected to the input component 100 and is used to output a stable trigger power supply. The trigger component 300 includes an optocoupler U1 and a shunt connected in parallel across the light-emitting element of the optocoupler. The power supply component 200 is connected to the light-emitting element of the optocoupler U1. The output component 400 is connected to the light-receiving element of the optocoupler. The output component 400 is also connected to the power supply AC1 / AC2 and the load. When the optocoupler U1 is turned on, the power supply AC1 / AC2 supplies power to the load through the output component 400.

[0032] This invention uses a shunt connected in parallel across the light-emitting element of an optocoupler to raise the trigger threshold (e.g., from 2.8–3.0 mA / 3V to 5.5 mA / 12.5V), enhancing anti-interference capabilities and preventing false triggering. The optocoupler isolates the input and output, improving electrical safety and reducing the impact of electromagnetic interference on the output. The shunt can be a resistor R1; by adjusting the value of R1, the trigger threshold can be flexibly set to adapt to different interference environments.

[0033] The input component 100 includes an input terminal J2, a filter capacitor C2 connected in parallel between the positive and negative terminals of the input terminal J2, and a diode D1 connected in series between the input terminal J2 and the power supply component 200. The anode of the diode D1 is connected to the input terminal, and the end of the filter capacitor C2 away from the diode D1 is grounded. By setting the filter capacitor C2, high-frequency noise interference is suppressed, and the diode D1 is used to prevent reverse connection, thereby avoiding damage to the device by reversing the power supply polarity.

[0034] The power supply component 200 includes an NPN transistor Q1, a Zener diode D2, a bias resistor R9, and a current-limiting resistor R4. The anode of the Zener diode D2 is grounded, and its cathode is connected to the base of the NPN transistor Q1. The collector of the NPN transistor Q1 is connected to the cathode of the diode D1 through the current-limiting resistor R4. The emitter of the NPN transistor Q1 is connected to the trigger component 300. The bias resistor R9 is connected in parallel between the end of the current-limiting resistor R4 furthest from the NPN transistor Q1 and the base of the NPN transistor Q1. The Zener diode D2 ensures a stable trigger voltage, such as 4V. The bias resistor R9 discharges charge, accelerating the switching on and off of the NPN transistor Q1 and improving the response speed.

[0035] The solid-state relay also includes an indicator component, which includes a light-emitting diode LED1 connected in series and then in parallel across the light-emitting element of the optocoupler, and a current-limiting resistor R10. The other end of the current-limiting resistor R10 is grounded. The operation of the relay can be intuitively displayed by the on / off state of the light-emitting diode LED1, which facilitates fault diagnosis.

[0036] The optocoupler used in this embodiment is a bidirectional thyristor optocoupler, suitable for AC load control, requiring no additional rectifier circuit. The output component 400 includes an output terminal J1, a first unidirectional thyristor U2A and a second unidirectional thyristor U2B connected in parallel between the positive and negative terminals of the output terminal, respectively. The first unidirectional thyristor U2A and the second unidirectional thyristor U2B are arranged in reverse order. The control terminals of the first unidirectional thyristor U2A and the second unidirectional thyristor U2B are connected one-to-one with the output terminal of the optocoupler U1. The two ends of the second unidirectional thyristor U2B are the live and neutral wire inputs AC1 and AC2 of the power supply. An eighth resistor R8 is connected in parallel between the control terminal of the second unidirectional thyristor U2B and its cathode, and a fifth resistor R5 is connected in parallel between the control terminal of the first unidirectional thyristor U2A and its cathode.

[0037] For ease of explanation, the cathode of the second unidirectional thyristor U2B is AC1, and the anode is AC2. When AC1 is connected to the live wire and AC2 is connected to the neutral wire, and the optocoupler U1 is turned on, current flows through AC1, the eighth resistor R8, and the light-receiving element of the optocoupler U1 to the control terminal of the first unidirectional thyristor U2A, causing the first unidirectional thyristor U2A to conduct, thus connecting the power supply circuit to the output terminal J1 (J1 is connected to a load). Conversely, when AC1 is connected to the neutral wire and AC2 is connected to the live wire, and the optocoupler U1 is turned on, current flows through AC2, the fifth resistor R5, and the light-receiving element of the optocoupler U1 to the control terminal of the second unidirectional thyristor U2B, causing the second unidirectional thyristor U2B to conduct, thus connecting the power supply circuit to the output terminal J1 (J1 is connected to a load). Therefore, power can be supplied to any plug inserted into the socket when the optocoupler is turned on.

[0038] In this embodiment, at least one end of the light-receiving component of the optocoupler is connected in series with the control terminal of the first unidirectional thyristor or the second unidirectional thyristor, and the output component 400 also includes a seventh resistor R7 connected in series and in parallel between the positive and negative terminals of the output terminal and a first capacitor C1, which are used to absorb switching peak voltages and protect the device.

[0039] The foregoing description illustrates and describes preferred embodiments of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the present invention through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A solid-state relay resistant to high-frequency interference, characterized in that, include: Input component, used to connect to control power; A power supply component, connected to the input component, is used to output a stable trigger power supply; A triggering component, the triggering component including an optocoupler and a shunt component connected in parallel to both ends of the light-emitting element of the optocoupler; The power supply component is connected to the light-emitting element of the optocoupler; The output component is connected to the light-receiving element of the optocoupler. The output component is also connected to the power supply and the load respectively. When the optocoupler is turned on, the power supply provides power to the load through the output component.

2. The solid-state relay for resisting high-frequency interference according to claim 1, characterized in that, The input component includes an input terminal, a filter capacitor connected in parallel between the positive and negative terminals of the input terminal, and a diode connected in series between the input terminal and the power supply component; the anode of the diode is connected to the input terminal, and the end of the filter capacitor furthest from the diode is grounded.

3. A solid-state relay for resisting high-frequency interference according to claim 1, characterized in that, The power supply component includes an NPN transistor connected to the input component, a Zener diode connected between the base of the NPN transistor and ground, and a bias resistor connected in parallel between the collector and base of the NPN transistor; the emitter of the NPN transistor is connected to the trigger component, and the collector of the NPN transistor is connected to the input component.

4. A solid-state relay for resisting high-frequency interference according to claim 3, characterized in that, The power supply component also includes a current-limiting resistor connected in series between the bias resistor and the common node of the input component and the collector of the NPN transistor.

5. A solid-state relay for resisting high-frequency interference according to claim 1, characterized in that, The shunt includes a first resistor.

6. A solid-state relay for resisting high-frequency interference according to claim 5, characterized in that, It also includes an indicator component, which includes a light-emitting diode connected in series and then in parallel across the light-emitting element of the optocoupler and a current-limiting resistor, with the other end of the current-limiting resistor grounded.

7. A solid-state relay for resisting high-frequency interference according to claim 1, characterized in that, The optocoupler is a bidirectional silicon controlled rectifier optocoupler.

8. A solid-state relay for resisting high-frequency interference according to claim 7, characterized in that, The output component includes an output terminal, a first unidirectional thyristor and a second unidirectional thyristor connected in parallel between the positive and negative terminals of the output terminal; the first unidirectional thyristor and the second unidirectional thyristor are arranged in opposite directions, and the control terminals of the first unidirectional thyristor and the second unidirectional thyristor are connected one-to-one with the two ends of the light-receiving component of the optocoupler; the anode and cathode of the second unidirectional thyristor are respectively connected to the live wire and the neutral wire of the power supply. An eighth resistor is connected in parallel between the control terminal of the first unidirectional thyristor and its cathode, and a fifth resistor is connected in parallel between the control terminal of the first unidirectional thyristor and its cathode.

9. A solid-state relay for resisting high-frequency interference according to claim 8, characterized in that, At least one end of the light-receiving element of the optocoupler is connected in series with the control terminal of the first unidirectional thyristor or the second unidirectional thyristor, and a current-limiting resistor is connected in series.

10. A solid-state relay for resisting high-frequency interference according to claim 7, characterized in that, The output component also includes a seventh resistor and a first capacitor connected in series and then in parallel between the positive and negative terminals of the output terminal.

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