Stable solid-state relay circuit

Abstract

The utility model relates to a relay, in particular to a stable solid-state relay circuit. The system comprises a control end and a controlled end. The circuit is characterized in that the control end comprises a first trigger circuit and an isolation circuit. And the controlled end comprises a trigger circuit II. A constant current circuit is arranged in the first trigger circuit, the first trigger circuit is adaptively connected with an amplifying circuit through an isolating circuit, and the amplifying circuit is adaptively connected with the second trigger circuit. An external control signal enters the first trigger circuit, the first trigger circuit generates a stable first trigger signal under the action of the constant current circuit, the first trigger signal generates a control signal in the amplifying circuit through the isolating circuit, and the control signal generates a second trigger signal through the second trigger circuit after being amplified by the amplifying circuit. The silicon controlled rectifier of the trigger circuit 2 works. By adopting the solid-state relay, the phenomenon that the controlled end cannot operate normally due to external interference is avoided.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of relays, specifically a kind of stable solid-state relay circuit. BACKGROUND

[0002] Solid state relay (SOLID STATE RELAYS) is a new type of non-contact switching device composed of solid-state electronic components, which uses the switching characteristics of electronic components (such as switching triode, bidirectional thyristor and other semiconductor devices) to achieve the purpose of switching on and off the circuit without contact and spark, so it is also called "non-contact switch". One of the functions of solid-state relay is to control strong current with weak current, i.e. the control end is a weak current signal. However, when using traditional solid-state relays, if there is external interference, the control end will not be stable under interference, resulting in the controlled end not running normally. SUMMARY

[0003] The technical problem to be solved by the utility model is to provide a stable solid-state relay circuit. Using the solid-state relay will not cause the controlled end to not run normally due to external interference.

[0004] To solve the above problems, the following technical solutions are provided:

[0005] The stable solid-state relay circuit of the utility model includes a control end and a controlled end. The control end includes a trigger circuit one and an isolation circuit. The controlled end contains a trigger circuit two. The trigger circuit one has a constant current circuit, and the trigger circuit one is connected to an amplification circuit through the isolation circuit. The amplification circuit is connected to the trigger circuit two. The external control signal enters the trigger circuit one, and the trigger circuit one generates a stable first trigger signal under the action of the constant current circuit. The first trigger signal generates a control signal in the amplification circuit through the isolation circuit. The control signal is amplified by the amplification circuit and generates a second trigger signal through the trigger circuit two. The silicon controlled rectifier of the trigger circuit two works.

[0006] The isolation circuit contains a first isolation optocoupler. The positive pin of the first isolation optocoupler is connected to one end of a recoverable fuse Fu. The other end of the recoverable fuse Fu is connected to a positive terminal V+. The external control signal enters the trigger circuit through the positive terminal V+. The light-sensitive transistor of the first isolation optocoupler is connected to the amplification circuit. The constant current circuit contains a transistor Q1. The negative pin of the first isolation optocoupler is connected to the base of the transistor Q1. The external control signal V1 is connected to one end of a resistor R2. The other end of the resistor R2 is connected to the emitter of the transistor Q1 and the positive terminal of a diode D1. The collector of the transistor Q1 is connected to a negative terminal V- through a resistor R3. The negative terminal of the diode D1 is connected to the negative terminal V-.

[0007] The one end of the recoverable fuse Fu connected with the positive pin of the first isolated optocoupler is connected with the negative electrode of the diode D2, and the positive electrode of the diode D2 is connected with the negative terminal V-.

[0008] The one end of the recoverable fuse Fu connected with the positive pin of the first isolated optocoupler is connected with one end of the resistor R1, the other end of the resistor R1 is connected with the positive electrode of the light emitting diode LED, and the negative electrode of the light emitting diode LED is connected with the negative terminal V-.

[0009] The second isolated optocoupler is connected in the amplification circuit, and the light-sensitive transistor of the second isolated optocoupler is connected with the thyristor; after the control signal is amplified by the amplification circuit, the light-sensitive transistor of the second isolated optocoupler is turned on, and the light-sensitive transistor of the second isolated optocoupler forms the second trigger signal to control the thyristor to work.

[0010] The above scheme has the following advantages:

[0011] The controlled end of the stable solid-state relay circuit of the utility model contains the trigger circuit two and the thyristor, the trigger circuit one has the constant current circuit, the trigger circuit one is connected with the amplification circuit through the isolation circuit, the amplification circuit is connected with the trigger circuit two, the external control signal enters the trigger circuit one, the trigger circuit one generates the stable first trigger signal under the action of the constant current circuit, the first trigger signal generates the control signal in the amplification circuit through the isolation circuit, the control signal generates the second trigger signal after being amplified by the amplification circuit, and the thyristor works. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 It is the structure topological graph of the stable solid-state relay circuit of the utility model;

[0013] Figure 2 It is the circuit schematic view of the stable solid-state relay circuit of the utility model. DETAILED DESCRIPTION

[0014] The utility model will be further explained in detail in combination with the drawings.

[0015] As Figure 1As shown, the stable solid-state relay circuit of the utility model includes control end and controlled end. Control end includes trigger circuit one and isolation circuit, trigger circuit contains constant current circuit, controlled end contains trigger circuit two. External control signal enters trigger circuit one, trigger circuit one produces stable first trigger signal under the action of constant current circuit, first trigger signal produces control signal in amplification circuit through isolation circuit, control signal produces second trigger signal after amplification through trigger circuit two, and the silicon controlled rectifier of control trigger circuit two works.

[0016] As shown in Figure 1 and Figure 2 , isolation circuit contains first isolated optocoupler, the positive pin of first isolated optocoupler is connected with one end of recoverable fuse Fu, and the other end of recoverable fuse Fu is connected with positive terminal V+. Recoverable fuse Fu forms short-circuit protection circuit. External control signal enters trigger circuit through positive terminal V+. The two ends of photosensitive transistor of first isolated optocoupler are adaptively connected in amplification circuit. Constant current circuit contains triode Q1, and the negative pin of first isolated optocoupler is connected with the base of triode Q1. External control signal V1 is connected with one end of resistance R2, and the other end of resistance R2 is connected with the emitter of triode Q1 and the positive electrode of diode D1, the collector of triode Q1 is connected with negative terminal V- through resistance R3, and the negative electrode of diode D1 is connected with negative terminal V-. In the embodiment, first isolated optocoupler contains optocoupler isolation chip U1 and optocoupler isolation chip U2, as shown in Figure 2 , optocoupler isolation chip U1 and optocoupler isolation chip U2 are connected in series, and the specific model of optocoupler isolation chip U1 and optocoupler isolation chip U2 can be selected by the person skilled in the art according to the needs, which belongs to the prior art and will not be described here.

[0017] As shown in Figure 2 , one end of recoverable fuse Fu connected with the positive pin of first isolated optocoupler is connected with the negative electrode of diode D2, and the positive electrode of diode D2 is connected with negative terminal V-, so that reverse connection is prevented.

[0018] As shown in Figure 2 , one end of recoverable fuse Fu connected with the positive pin of first isolated optocoupler is connected with one end of resistance R1, the other end of resistance R1 is connected with the positive electrode of light-emitting diode LED, and the negative electrode of light-emitting diode LED is connected with negative terminal V-. Input signal indication is realized by using light-emitting diode LED.

[0019] As shown in Figure 2 , trigger circuit one is adaptively connected with amplification circuit through isolation circuit, and amplification circuit is adaptively connected with trigger circuit two. The connection mode of trigger circuit one, amplification circuit and trigger circuit two and the specific structure of amplification circuit can be selected by the person skilled in the art according to the needs, which belongs to the prior art and will not be described here.

[0020] As Figure 2 shown, the trigger circuit two contains a second isolation optocoupler, the positive and negative of the second isolation optocoupler are connected in the amplification circuit, the phototransistor of the second isolation optocoupler is connected with the thyristor. After the control signal is amplified by the amplification circuit, the phototransistor of the second isolation optocoupler is turned on through the positive and negative of the second isolation optocoupler, and the phototransistor of the second isolation optocoupler forms a second trigger signal to control the thyristor to work. In this embodiment, the second isolation optocoupler contains optocoupler isolation chip U3 and optocoupler isolation chip U4, as shown in Figure 2 shown, the optocoupler isolation chip U3 and the optocoupler isolation chip U4 are connected in series, and the specific model of the optocoupler isolation chip U3 and the optocoupler isolation chip U4 can be selected by those skilled in the art according to the needs, which belongs to the prior art and will not be described here. The specific connection structure of the optocoupler isolation chip U3 and the optocoupler isolation chip U4 and the thyristor is shown in Figure 2 , which belongs to the prior art and will not be described here.

[0021] The external control signal enters the trigger circuit one, and the trigger circuit one generates a stable first trigger signal under the action of the constant current circuit. The first trigger signal generates a control signal in the amplification circuit through the isolation circuit, and the control signal generates a second trigger signal through the trigger circuit two after being amplified by the amplification circuit, controls the thyristor to work, and realizes the function of the relay. The trigger circuit one of the solid-state relay uses the constant current circuit to form a stable first trigger signal, so that a stable trigger signal can still be formed when there is interference from the outside world, avoiding the situation that the controlled end cannot operate normally due to external interference. Moreover, the control signal is twice isolated from the output part, and the safety is high.

Claims

1. A stable solid state relay circuit comprising a control terminal and a controlled terminal; characterized by, The control end includes trigger circuit one and isolation circuit; the controlled end contains trigger circuit two; the trigger circuit one has constant current circuit, and the trigger circuit one is connected with amplification circuit through the isolation circuit, and the amplification circuit is connected with the trigger circuit two; the external control signal enters the trigger circuit one, the trigger circuit one generates stable first trigger signal under the action of the constant current circuit, the first trigger signal generates control signal in the amplification circuit through the isolation circuit, the control signal generates second trigger signal through the trigger circuit two after being amplified by the amplification circuit, and the thyristor of the trigger circuit two works.

2. The stable solid state relay circuit of claim 1, wherein, The isolation circuit contains first isolation optocoupler, and the anode pin of the first isolation optocoupler is connected with one end of the resettable fuse Fu, the other end of the resettable fuse Fu is connected with the positive terminal V+, and the external control signal enters the trigger circuit through the positive terminal V+; the phototransistor of the first isolation optocoupler is adaptively connected in the amplification circuit; the constant current circuit contains triode Q1, the cathode pin of the first isolation optocoupler is connected with the base of the triode Q1; the external control signal is connected with one end of the resistor R2, the other end of the resistor R2 is connected with the emitter of the triode Q1 and the anode of the diode D1, the collector of the triode Q1 is connected with the negative terminal V- through the resistor R3, and the cathode of the diode D1 is connected with the negative terminal V-.

3. The stable solid state relay circuit of claim 2, wherein, The one end of the resettable fuse Fu connected with the anode pin of the first isolation optocoupler is connected with the cathode of the diode D2, and the anode of the diode D2 is connected with the negative terminal V-.

4. The stable solid state relay circuit of claim 2, wherein, The one end of the resettable fuse Fu connected with the anode pin of the first isolation optocoupler is connected with one end of the resistor R1, the other end of the resistor R1 is connected with the anode of the light emitting diode LED, and the cathode of the light emitting diode LED is connected with the negative terminal V-.

5. The stable solid state relay circuit of claim 1, wherein, The trigger circuit two contains second isolation optocoupler, and the anode and cathode of the second isolation optocoupler are adaptively connected in the amplification circuit, and the phototransistor of the second isolation optocoupler is adaptively connected with the thyristor; after the control signal is amplified by the amplification circuit, the anode and cathode of the second isolation optocoupler are passed, the phototransistor of the second isolation optocoupler is turned on, and the phototransistor of the second isolation optocoupler forms the second trigger signal to control the thyristor to work.

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