An anti-interference isolation control circuit

Abstract

The application discloses an anti-interference isolation control circuit and relates to the technical field of isolation driving, which comprises a charge leakage circuit, a delay circuit, a thyristor switch threshold circuit and an isolation driving circuit; wherein the input end of the charge leakage circuit is connected with the control signal of a system control circuit, and the output end of the charge leakage circuit is connected with the delay circuit in parallel; the output end of the delay circuit is connected with the input end of the thyristor switch threshold circuit, and the output end of the thyristor switch threshold circuit is connected with a load circuit through the isolation driving circuit. The application alleviates the technical problem that the uncertainty signal or electromagnetic interference in the prior art is prone to causing the functional mis-triggering in the power distribution system.

Description

Technical Field

[0001] This invention relates to the field of isolation drive technology, and in particular to an anti-interference isolation control circuit. Background Technology

[0002] In power distribution systems, uncertain signals caused by power outages and resets, or interference signals generated by electromagnetic interference, may be misinterpreted as valid control signals, thereby causing critical functions of the power distribution system to be erroneously triggered and malfunction. Summary of the Invention

[0003] To address the aforementioned technical problems in the existing technology, embodiments of the present invention provide an anti-interference isolation control circuit. The technical solution is as follows: This invention provides an anti-interference isolation control circuit for use in power distribution systems; it includes: a charge discharge circuit, a delay circuit, a thyristor switching threshold circuit, and an isolation drive circuit; wherein, the input terminal of the charge discharge circuit is connected to the control signal of the system control circuit, and the output terminal of the charge discharge circuit is connected in parallel with the delay circuit; the output terminal of the delay circuit is connected to the input terminal of the thyristor switching threshold circuit, and the output terminal of the thyristor switching threshold circuit is connected to the load circuit through the isolation drive circuit.

[0004] Optionally, the charge discharge circuit includes a first resistor and a diode, and the delay circuit includes a second resistor and a capacitor; one end of the first resistor and the negative terminal of the diode are connected to the control signal, the second resistor and the capacitor are connected in series and then connected in parallel with the two ends of the first resistor, and the positive terminal of the diode is connected to the connection point of the second resistor and the capacitor.

[0005] Optionally, the thyristor switching threshold circuit includes a second resistor, a Zener diode, a third resistor, a thyristor, and a fourth resistor; wherein the second resistor, the Zener diode, and the third resistor constitute the turn-on threshold circuit of the thyristor, and the fourth resistor and the thyristor constitute the turn-off threshold circuit of the thyristor.

[0006] Optionally, the fourth resistor is connected in series between the delay circuit and the input terminal of the isolation drive circuit, the input terminal of the isolation drive circuit is also connected to the thyristor, the two ends of the Zener diode are respectively connected to the connection point of the second resistor and the capacitor and the thyristor, and one end of the third resistor is connected to the connection point of the Zener diode and the thyristor.

[0007] Optionally, the isolation drive circuit includes a magnetic isolation element or an optical isolation element.

[0008] This invention provides an anti-interference isolation control circuit that uses the holding current and latching current of a thyristor to set the voltage hysteresis and delay of the control signal, and uses an isolation drive circuit to prevent interference between high and low voltage circuits. This effectively avoids false triggering of interference signals and ensures that the system function is not interrupted by signal fluctuations after the control signal takes effect. It alleviates the technical problem in the prior art that uncertain signals or electromagnetic interference can easily lead to false triggering of functions in the power distribution system. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 A schematic diagram of an anti-interference isolation control circuit provided in an embodiment of the present invention; Figure 2 This is a circuit diagram of an anti-interference isolation control circuit provided in an embodiment of the present invention.

[0011] In the diagram: 1. First resistor, 2. Diode, 3. Second resistor, 4. Capacitor, 5. Zener diode, 6. Third resistor, 7. Thyristor, 8. Fourth resistor, 10. Charge discharge circuit, 20. Delay circuit, 30. Thyristor switching threshold circuit, 40. Isolation drive circuit, 50. System control circuit, 60. Load circuit. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0013] Figure 1 This is a schematic diagram of an anti-interference isolation control circuit according to an embodiment of the present invention, which is applied to a power distribution system. Figure 1As shown, it includes: a charge discharge circuit 10, a delay circuit 20, a thyristor switching threshold circuit 30, and an isolation drive circuit 40; wherein, the input terminal of the charge discharge circuit 10 is connected to the control signal of the system control circuit 50, and the output terminal of the charge discharge circuit 10 is connected in parallel with the delay circuit 20; the output terminal of the delay circuit 20 is connected to the input terminal of the thyristor switching threshold circuit 30, and the output terminal of the thyristor switching threshold circuit 30 is connected to the load circuit 60 through the isolation drive circuit 40.

[0014] Figure 2 This is a circuit diagram of an anti-interference isolation control circuit provided according to an embodiment of the present invention. Figure 2 As shown, the charge discharge circuit 10 includes a first resistor 1 and a diode 2, and the delay circuit 20 includes a second resistor 3 and a capacitor 4. One end of the first resistor 1 and the negative terminal of the diode 2 are connected to the control signal. The second resistor 3 and the capacitor 4 are connected in series and then connected in parallel with the two ends of the first resistor 1. The positive terminal of the diode 2 is connected to the connection point of the second resistor 3 and the capacitor 4.

[0015] Specifically, the first resistor 1 and the diode 2 form a charge discharge circuit 10, which is used to accelerate the charge discharge of the capacitor 4; the second resistor 3 and the capacitor 4 form an RC delay circuit, which is used to filter short-time pulse interference signals.

[0016] Specifically, such as Figure 2 As shown, the thyristor switching threshold circuit 30 includes a second resistor 3, a Zener diode 5, a third resistor 6, a thyristor 7, and a fourth resistor 8. The second resistor 3, the Zener diode 5, and the third resistor 6 constitute the turn-on threshold circuit of the thyristor 7, which is used to filter low-voltage interference signals. The fourth resistor 8 and the thyristor 7 constitute the turn-off threshold circuit of the thyristor 7. When the main path current is less than the holding current of the thyristor 7, the main path is automatically turned off.

[0017] Specifically, such as Figure 2 As shown, the fourth resistor 8 is connected in series between the delay circuit 20 and the input terminal of the isolation drive circuit 40. The input terminal of the isolation drive circuit 40 is also connected to the thyristor 7. The two ends of the Zener diode 5 are respectively connected to the connection point of the second resistor 3 and the capacitor 4 and the thyristor 7. One end of the third resistor 6 is connected to the connection point of the Zener diode 5 and the thyristor 7.

[0018] Optionally, the isolation drive circuit 40 includes a magnetic isolation element or an optical isolation element. Preferably, such as Figure 2 As shown, the isolation drive circuit 40 is an optical isolation element. In this embodiment of the invention, the load circuit 60 is isolated from the system control circuit 50 to prevent signal fluctuations after connection from causing false shutdown.

[0019] The working principle of the anti-interference isolation control circuit provided in this embodiment of the invention is as follows: The control signal issued by the system control circuit 50 of the power distribution system charges the capacitor 4 through the second resistor 3. When the voltage of the capacitor 4 exceeds the voltage regulation value of the Zener diode 5 and the turn-on voltage threshold of the thyristor 7, the thyristor 7 turns on to supply power to the downstream isolation drive circuit 40. When the control signal is lower than a certain value, the main path current is lower than the holding current of the thyristor 7, causing the thyristor 7 to turn off, and the isolation drive circuit 40 is de-energized.

[0020] The anti-interference isolation control circuit provided in this invention utilizes the holding current and latching current of the thyristor to achieve voltage hysteresis setting and delay setting of the control signal, and uses an isolation drive circuit to prevent interference between high and low voltage circuits. It can effectively avoid false triggering of interference signals, ensure that the system function is not interrupted due to signal fluctuations after the control signal takes effect, and has a simple structure. It alleviates the technical problem that uncertain signals or electromagnetic interference can easily lead to false triggering of functions in the power distribution system in the prior art.

[0021] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0022] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An anti-interference isolation control circuit, characterized in that, This system is applied to power distribution systems and includes: a charge discharge circuit, a delay circuit, a thyristor switching threshold circuit, and an isolation drive circuit. The input of the charge discharge circuit is connected to a control signal from a system control circuit, and the output of the charge discharge circuit is connected in parallel with the delay circuit. The output of the delay circuit is connected to the input of the thyristor switching threshold circuit, and the output of the thyristor switching threshold circuit is connected to a load circuit via the isolation drive circuit.

2. The anti-interference isolation control circuit according to claim 1, characterized in that: The charge discharge circuit includes a first resistor and a diode, and the delay circuit includes a second resistor and a capacitor; one end of the first resistor and the negative terminal of the diode are connected to the control signal, the second resistor and the capacitor are connected in series and then connected in parallel with the two ends of the first resistor, and the positive terminal of the diode is connected to the connection point of the second resistor and the capacitor.

3. The anti-interference isolation control circuit according to claim 2, characterized in that: The thyristor switching threshold circuit includes a second resistor, a Zener diode, a third resistor, a thyristor, and a fourth resistor; wherein, the second resistor, the Zener diode, and the third resistor constitute the turn-on threshold circuit of the thyristor, and the fourth resistor and the thyristor constitute the turn-off threshold circuit of the thyristor.

4. The anti-interference isolation control circuit according to claim 3, characterized in that: The fourth resistor is connected in series between the delay circuit and the input terminal of the isolation drive circuit. The input terminal of the isolation drive circuit is also connected to the thyristor. The two ends of the Zener diode are respectively connected to the connection point of the second resistor and the capacitor and the thyristor. One end of the third resistor is connected to the connection point of the Zener diode and the thyristor.

5. The anti-interference isolation control circuit according to claim 1, characterized in that: The isolation drive circuit includes magnetic isolation elements or optical isolation elements.

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