Control short-circuit protection circuit of electric actuator

Abstract

The utility model relates to the field of protection circuits, in particular to an electric actuator control short-circuit protection circuit, which comprises an input end connected with a load, a voltage conversion circuit for converting the voltage of the input end into the working voltage of a relay, and a short-circuit protection circuit, the short-circuit protection circuit comprises a switch SW1 for starting the protection circuit, an SPDT relay K5 for controlling the state of the short-circuit protection circuit, a DPDT relay K6 for controlling the connection state of an input end and a load, a work indication branch connected with the NO end of the relay K5, and a short-circuit indication branch connected with the NC end of the relay K5; one end of the switch SW1 is connected with the working voltage of the relay and the COM end of the relay K5, and the other end of the switch SW1 is connected with the NO end of the relay K5; the NO end of the relay K5 is connected with the control end of the relay K5 and the control end of the relay K6. After the SW1 is conducted, the relay K5 forms a self-locking loop, and the relay K6 controls the load to be powered on; and when the load is short-circuited, the relay K6 controls the negative end to be powered off, and the relay K5 is switched into a short-circuit indication branch to prompt that the load is abnormal.

Description

Technical Field

[0001] The utility model relates to the field of protection circuits, and particularly to a short-circuit protection circuit for electric actuator control. Background Art

[0002] The power supply system needs to supply power to each household in a building. Before the installation of a circuit breaker, as long as there is a short circuit in the electric valve actuator controller of one household in the whole building, the entire system will be in a short-circuit state. At this time, it is difficult and time-consuming to find the short-circuited household. The power supply short circuit may also damage the power supply equipment of the collector and cause abnormal data collection. Therefore, there is an urgent need for a circuit device that can protect the overall power supply and quickly detect the short-circuit location. Summary of the Utility Model

[0003] To solve the above problems, the utility model provides a short-circuit protection circuit for electric actuator control, including:

[0004] An input end connected to a load, a voltage conversion circuit for converting the input end voltage into a relay operating voltage, and a short-circuit protection circuit;

[0005] The short-circuit protection circuit includes a switch SW1 for starting the protection circuit, an SPDT relay K5 for controlling the state of the short-circuit protection circuit, a DPDT relay K6 for controlling the connection state between the input end and the load, a working indication branch connected to the NO terminal of the relay K5, and a short-circuit indication branch connected to the NC terminal of the relay K5;

[0006] One end of the switch SW1 is connected to the relay operating voltage and the COM terminal of the relay K5, and the other end is connected to the NO terminal of the relay K5; the NO terminal of the relay K5 is connected to the control terminal of the relay K5 and the control terminal of the relay K6; after the switch SW1 is turned on, the COM terminal, NO terminal, and control terminal of the relay K5 form a self-locking loop.

[0007] Further, the two COM terminals of the DPDT relay K6 are respectively connected to the positive and negative poles of the input end, and the two NO terminals of the DPDT relay K6 are respectively connected to both ends of the load.

[0008] Further, the working indication branch is a series connection of a light-emitting diode LG and a resistor R2.

[0009] Further, the short-circuit indication branch is a series connection of a light-emitting diode LR and a resistor R1.

[0010] Further, the relay K5, relay K6, working indication branch, and short-circuit indication branch share a common ground.

[0011] In summary, the utility model has at least the following beneficial effects:

[0012] In the present utility model, the switch SW1 is connected in parallel with the COM terminal and the NO terminal of the relay K5, and the NO terminal of K5 is connected to the control terminal of K5. When SW1 is pressed to conduct, the control terminal of K5 receives a high level, the COM terminal and the NO terminal are conducted, and K5 forms a self-locking loop. At this time, after SW1 is disconnected, the control terminals of K5 and K6 still receive a high level, and the load can work normally, and the light-emitting diode LG in the working indication branch lights up.

[0013] When the load is short-circuited, the output voltage of the voltage conversion circuit decreases and cannot meet the minimum voltage for the operation of the relay K5. The COM terminal and the NO terminal are disconnected, and the two paths of the relay K6 are switched to the NC terminal, and the two ends of the load are powered off, and the input voltage returns to normal; at the same time, the COM terminal and the NC terminal of the relay K5 are conducted, and the light-emitting diode LR in the short-circuit indication branch lights up to indicate that the load is abnormal. Brief Description of the Drawings

[0014] Figure 1 It is the voltage conversion circuit diagram of the present utility model;

[0015] Figure 2 It is the short-circuit protection circuit diagram of the present utility model. Specific Embodiments

[0016] The following further describes the present utility model in detail Figure 1-2 with reference to the accompanying drawings.

[0017] As Figure 1 shown, in this embodiment, the voltage at both ends of the input terminal is +24V and -24V, and the voltage conversion circuit uses a bridge rectifier DF10S and then is converted into a +5V voltage through a DC-DC voltage chip.

[0018] As Figure 2As shown in the figure, one end of the switch SW1 is connected to the +5V and the COM terminal of the single-pole double-throw relay K5, and the other end of the switch SW1 is connected to the NO terminal of the relay K5. At the same time, the NO terminal of the relay K5 is connected to the control terminal of the relay K5, the control terminal of the relay K6, and the positive electrode of the light-emitting diode LG in the working indication branch. The negative electrode of the LG is connected to the current-limiting resistor R2. In this embodiment, R2 is taken as 1 kΩ; the NC terminal of the relay K5 is connected to the positive electrode of the light-emitting diode LR in the short-circuit indication branch, and the negative electrode of the LR is connected to the current-limiting resistor R1 with the same resistance value of 1 kΩ. The function of the double-pole double-throw relay K6 is to control the connection state between the input voltage and the load. The two ends of the input are respectively connected to the COM terminals of the two paths of the relay K6, and the two ends of the load are respectively connected to the NO terminals of the two paths of the relay K6. In order to avoid component damage caused by the instantaneous high-voltage discharge of the inductor inside the relay when the power is off, a freewheeling diode D4 is connected between the NO terminal of K5 and the GND to provide a discharge path for the inductor in the relay. One end of the above-mentioned relay K5, relay K6, resistor R1, and one end of resistor R2 are grounded together with the DC-DC voltage chip.

[0019] In this embodiment, SW1 is a normally open self-resetting push-button switch, that is, SW1 is turned on when pressed and randomly turned off after release. When SW1 is turned on, the control terminal of the relay K5 is connected to a high level, and the COM terminal and the NO terminal of the relay K5 are turned on. At this time, a self-locking loop is formed among the COM terminal, the NO terminal, and the control terminal of the relay K5. After releasing SW1, the COM terminal and the NO terminal also remain turned on. The control terminal of the relay K6 inputs a high level, and the COM terminal and the NO terminal of the two paths are turned on, and the input is connected to the load, and the load is powered on. When the load is short-circuited, the output voltage of the voltage conversion circuit decreases and cannot meet the minimum voltage for the operation of the relay K5. The COM terminal and the NO terminal are disconnected, and the COM terminal and the NC terminal are turned on. The two paths of the relay K6 are switched to the NC terminal, and the two ends of the load are powered off. After the short-circuited load is removed, the voltage on both sides of the input returns to normal, and at the same time, the light-emitting diode LR in the short-circuit indication branch lights up to indicate that the load is abnormal.

[0020] The above are all the preferred embodiments of the present invention, and the protection scope of the present invention is not limited accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of the present invention should be covered within the protection scope of the present invention.

Claims

1. An electric actuator control short-circuit protection circuit, characterized in that: including an input terminal connected to a load, a voltage conversion circuit for converting the input terminal voltage into a relay operating voltage, and a short-circuit protection circuit; the short-circuit protection circuit includes a switch SW1 for starting the protection circuit, an SPDT relay K5 for controlling the state of the short-circuit protection circuit, a DPDT relay K6 for controlling the connection state between the input terminal and the load, an operating indication branch connected to the NO terminal of the relay K5, and a short-circuit indication branch connected to the NC terminal of the relay K5; one end of the switch SW1 is connected to the relay operating voltage and the COM terminal of the relay K5, and the other end is connected to the NO terminal of the relay K5; the NO terminal of the relay K5 is connected to the control terminal of the relay K5 and the control terminal of the relay K6; after the switch SW1 is turned on, a self-locking loop is formed among the COM terminal, NO terminal, and control terminal of the relay K5.

2. The short-circuit protection circuit for electric actuator control according to claim 1, characterized in that: the two COM terminals of the DPDT relay K6 are respectively connected to the two poles of the input terminal, and the two NO terminals of the DPDT relay K6 are respectively connected to both ends of the load.

3. The short-circuit protection circuit for controlling an electric actuator according to claim 1, characterized in that: the operating indication branch is a series connection of a light-emitting diode LG and a resistor R2.

4. An electric actuator control short-circuit protection circuit according to claim 1, characterized in that: the short-circuit indication branch is a series connection of a light-emitting diode LR and a resistor R1.

5. The short - circuit protection circuit for electric actuator control according to claim 1, characterized in that: the voltage conversion circuit, the relay K5, the relay K6, the operating indication branch, and the short-circuit indication branch are grounded together.

6. The short-circuit protection circuit for electric actuator control according to claim 5, characterized in that: a freewheeling diode D4 is connected between the NO terminal of the relay K5 and GND, the negative electrode of the freewheeling diode D4 is connected to the NO terminal of the relay K5, and the positive electrode is connected to GND.

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