Output short-circuit protection circuit based on voltage-regulator tube

Abstract

The invention discloses an output short-circuit protection circuit based on a voltage-regulator tube, and belongs to the technical field of output short-circuit protection circuits. The circuit comprises a rectification module used for converting alternating current of a preset input end into direct current; the control module is connected with the rectification module and is used for controlling the direct current to be transmitted to the load of the preset output end; a short circuit protection control module; and the switching module is connected with the rectifier module and the control module and is used for switching off the control module when the load is short-circuited. The short-circuit protection circuit realizes short-circuit protection in a simple and low-cost manner.

Description

Technical Field

[0001] The present application relates to the technical field of output short-circuit protection circuits, and in particular to an output short-circuit protection circuit based on a voltage regulator tube. Background Art

[0002] Output short-circuit protection control is a basic and important technology that plays a key role in many fields such as industrial control, consumer electronics, and data communications. When the load is short-circuited, if there is no reliable protection circuit, it may cause unnecessary losses such as equipment damage. Short-circuit protection is regarded as a basic safety requirement for all power distribution outputs. By implementing effective short-circuit protection, the stability of system operation and long-term reliability can be ensured.

[0003] In circuit design, for safety reasons, short-circuit protection is usually added to quickly cut off the circuit and prevent equipment damage caused by short circuits. However, there are some problems with the existing implementation of output short-circuit protection circuits. For example, some circuits use fuses or circuit breakers to achieve short-circuit protection, which is direct but costly; while others use more complex overcurrent detection circuits to prevent excessive output current. Although such circuits are effective, they are complex in design and require the setting of parameters such as overcurrent thresholds, which increases the difficulty and cost of implementation.

[0004] Therefore, how to achieve short-circuit protection simply and at low cost has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The embodiment of the present application provides an output short-circuit protection circuit based on a voltage regulator tube to solve the following technical problem: how to implement short-circuit protection simply and at low cost.

[0006] An embodiment of the present application provides an output short-circuit protection circuit based on a voltage regulator tube, which is applied to a load. The circuit includes: a rectifier module, which is used to convert the alternating current at a preset input end into direct current; a control module, which is connected to the rectifier module and is used to control the direct current to be delivered to the load at a preset output end; and a short-circuit protection control module; which is connected to the rectifier module and the control module and is used to shut down the control module when the load is short-circuited.

[0007] In one implementation of the present application, the rectifier module includes a transformer, a capacitor and a diode; the transformer includes a primary winding and a secondary winding; the primary winding of the transformer is connected to the input end, one end of the secondary winding of the transformer is grounded, and the other end of the secondary winding is connected to the positive electrode of the diode; the negative electrode of the diode is connected to the positive electrode of the capacitor, and the negative electrode of the capacitor is grounded.

[0008] In one implementation of the present application, the short-circuit protection control module includes a first NPN transistor, a second NPN transistor, a second PNP transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a voltage regulator and an indicator light; the base of the first NPN transistor is connected to one end of the fourth resistor, and the other end of the fourth resistor is grounded; the base of the second NPN transistor is grounded, the collector of the second NPN transistor is connected to one end of the first resistor, and the other end of the first resistor is connected to the positive electrode of the capacitor; the base of the second PNP transistor is connected to the positive electrode of the capacitor, and the second PN The collector of the P transistor is connected to one end of the sixth resistor, and the other end of the sixth resistor is connected to the emitter of the second NPN transistor; the emitter of the first NPN transistor is connected to one end of the third resistor, and the other end of the third resistor is connected to one end of the first resistor; the emitter of the second PNP transistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the positive electrode of the capacitor; the emitter of the second PNP transistor is connected to the positive electrode of the indicator light, the negative electrode of the indicator light is connected to the negative electrode of the Zener diode, the positive electrode of the Zener diode is connected to one end of the second resistor, and the other end of the second resistor is connected to the positive electrode of the output end.

[0009] In one implementation of the present application, the control module is a first PNP transistor; the positive electrode of the capacitor is connected to the base of the first PNP transistor, the collector of the first PNP transistor is connected to the positive electrode of the output end, and the emitter of the first PNP transistor is connected to the collector of the first NPN transistor.

[0010] In one implementation of the present application, when the positive electrode of the output terminal is grounded, the load is short-circuited; the voltage of the positive electrode of the capacitor is connected to the negative electrode of the Zener diode through the fifth resistor, the indicator light, so that the Zener diode breaks down in reverse.

[0011] In one implementation of the present application, the reverse breakdown of the voltage regulator reduces the base voltage of the second PNP transistor; the base voltage of the second PNP transistor is greater than the emitter voltage of the second PNP transistor, so that the second PNP transistor is turned on.

[0012] In an implementation of the present application, the second PNP transistor is turned on to make the base of the second NPN transistor a high level, so as to turn on the second NPN transistor.

[0013] In one implementation of the present application, the second NPN transistor is turned on to reduce the base voltage of the first NPN transistor, so that the first NPN transistor is turned off; the first NPN transistor is turned off to close the current loop between the emitter and the base of the first PNP transistor, and the first PNP transistor is turned off to turn off the control module.

[0014] In one implementation of the present application, when the positive electrode of the output terminal is connected to the load; the positive electrode of the capacitor is connected to the emitter of the first NPN transistor through the first resistor and the third resistor, and the collector of the first NPN transistor is connected to the emitter of the first PNP transistor to turn on the first PNP transistor to turn on the control module.

[0015] In one implementation of the present application, the collector of the first NPN transistor is connected to the emitter of the first PNP transistor to turn on the first PNP transistor; the first PNP transistor is turned on so that the input end supplies power to the output end through the diode and the first PNP transistor.

[0016] The embodiment of the present application provides an output short-circuit protection circuit based on a voltage regulator tube, which converts AC power into DC power through a rectifier module, and uses a control module to control the DC power to be delivered to the load so that the load can work normally. When the load is short-circuited, the voltage regulator tube reversely breaks down, triggering the second PNP transistor to turn on, and then turning on the second NPN transistor. The second NPN transistor turns on to turn off the first NPN transistor, and finally turns off the control module, cutting off the power output, effectively preventing equipment damage caused by short circuits. When the load is connected normally, the circuit works normally to ensure power supply. Therefore, the circuit of the present application has the effect of simple structure and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 A structural diagram of an output short-circuit protection circuit based on a voltage regulator tube provided in an embodiment of the present application.

[0019] Reference numerals:

[0020] T, transformer; D1, diode; C1, capacitor; Q1, first PNP transistor; Q2, first NPN transistor; Q3, second NPN transistor; Q4, second PNP transistor; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; D2, voltage regulator; D3, indicator light. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0022] The embodiment of the present application provides an output short-circuit protection circuit based on a voltage regulator tube to solve the following technical problem: how to implement short-circuit protection simply and at low cost.

[0023] The technical solution proposed in the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0024] Figure 1 This is a diagram of an output short circuit protection circuit structure based on a voltage regulator tube provided in an embodiment of the present application. Figure 1 As shown, a structure diagram of an output short-circuit protection circuit based on a voltage regulator tube in an embodiment of the present application includes:

[0025] A rectifier module, used to convert the AC power at a preset input end into DC power; a control module, connected to the rectifier module, used to control the DC power to be delivered to the load at a preset output end; a short-circuit protection control module; connected to the rectifier module and the control module, used to shut down the control module when the load is short-circuited.

[0026] The rectifier module is used to convert the AC power at the preset input end into DC power. Specifically, the rectifier module includes a transformer T, a capacitor C1 and a diode D1.

[0027] Transformer T: Transformer T includes a primary winding and a secondary winding. The primary winding is connected to the input terminal for receiving an external AC power source. One end of the secondary winding is grounded, and the other end is connected to the positive electrode of the diode D1. The function of transformer T is to convert the input high voltage AC into a lower voltage AC.

[0028] Diode D1: The cathode of diode D1 is connected to the anode of capacitor C1. The function of diode D1 is to convert alternating current into unidirectional direct current, that is, current is only allowed to flow in one direction.

[0029] Capacitor C1: The negative electrode of capacitor C1 is grounded. The function of capacitor C1 is to smooth the direct current, reduce voltage fluctuations, and make the direct current output through diode D1 more stable.

[0030] The control module is connected to the rectifier module and is used to control the DC power to be delivered to the load at the preset output terminal. In this embodiment, the control module is a first PNP transistor Q1.

[0031] The first PNP transistor Q1 is configured as follows: the positive electrode of the capacitor C1 is connected to the base of the first PNP transistor Q1, the collector of the first PNP transistor Q1 is connected to the positive electrode of the output terminal, and the emitter is connected to the collector of the first NPN transistor Q2. When the first PNP transistor Q1 is turned on, direct current is allowed to flow from the rectifier module to the output terminal; when the first PNP transistor Q1 is turned off, the supply of direct current is cut off.

[0032] The short-circuit protection control module is connected to the rectifier module and the control module, and is used to shut down the control module when the load is short-circuited.

[0033] The short circuit protection control module includes a first NPN transistor Q2, a second NPN transistor Q3, a second PNP transistor Q4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a voltage regulator D2 and an indicator light D3. The short-circuit protection control module includes a first NPN transistor Q2, a second NPN transistor Q3, a second PNP transistor Q4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a voltage regulator D2 and an indicator light D3; the base of the first NPN transistor Q2 is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 is grounded; the base of the second NPN transistor Q3 is grounded, the collector of the second NPN transistor Q3 is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the positive electrode of the capacitor C1; the base of the second PNP transistor Q4 is connected to the positive electrode of the capacitor C1, and the second PNP transistor Q5 is connected to the positive electrode of the capacitor C1. The collector of Q4 is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the emitter of the second NPN transistor Q3; the emitter of the first NPN transistor Q2 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to one end of the first resistor R1; the emitter of the second PNP transistor Q4 is connected to one end of the fifth resistor R5, and the other end of the fifth resistor R5 is connected to the positive electrode of the capacitor C1; the emitter of the second PNP transistor Q4 is connected to the positive electrode of the indicator light D3, the negative electrode of the indicator light D3 is connected to the negative electrode of the voltage regulator D2, the positive electrode of the voltage regulator D2 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the positive electrode of the output end.

[0034] The first NPN transistor Q2 is configured as follows: the base is connected to one end of the fourth resistor R4, and the other end of the fourth resistor R4 is grounded. When the voltage on the fourth resistor R4 changes, the conduction state of the first NPN transistor Q2 is affected.

[0035] The second NPN transistor Q3 is configured as follows: the base is grounded, the collector is connected to one end of the first resistor R1, and the other end of the first resistor R1 is connected to the positive electrode of the capacitor C1. The state of the second NPN transistor Q3 is affected by other components and is used to control the on and off of the circuit.

[0036] The second PNP transistor Q4 is configured as follows: the base is connected to the positive electrode of the capacitor C1, the collector is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is connected to the emitter of the second NPN transistor Q3. The state of the second PNP transistor Q4 is affected by the voltage of the capacitor C1 and is used to control the base voltage of the second NPN transistor Q3.

[0037] The setting of the first resistor R1 to the sixth resistor R6: the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 respectively play the role of current limiting, voltage dividing and current shunting, so as to ensure the stable operation of the circuit of the embodiment of the present application to a certain extent.

[0038] The setting of the voltage regulator tube D2: the positive electrode of the voltage regulator tube D2 is connected to one end of the second resistor R2, and the other end of the second resistor R2 is connected to the positive electrode of the output end. The negative electrode of the voltage regulator tube D2 is connected to the negative electrode of the indicator light D3. When the positive electrode of the output end is grounded (i.e., the load is short-circuited), the positive electrode voltage of the capacitor C1 is connected to the negative electrode of the voltage regulator tube D2 through the fifth resistor R5 and the indicator light D3, resulting in reverse breakdown of the voltage regulator tube D2.

[0039] Setting of indicator light D3: The positive electrode of indicator light D3 is connected to the emitter of the second PNP transistor Q4. When the control module is turned off (i.e., when the load is short-circuited), the current passes through indicator light D3, and indicator light D3 lights up to remind relevant staff or monitoring equipment that the load is short-circuited.

[0040] The implementation principle of the present application is as follows: when the positive electrode of the output terminal is grounded and the load is short-circuited; the voltage of the positive electrode of the capacitor C1 is connected to the negative electrode of the voltage regulator D2 through the fifth resistor R5 and the indicator light D3, so that the voltage regulator D2 breaks down in reverse. The voltage regulator D2 breaks down in reverse, which reduces the base voltage of the second PNP transistor Q4; the base voltage of the second PNP transistor Q4 is greater than the emitter voltage of the second PNP transistor Q4, so that the second PNP transistor Q4 is turned on. The second PNP transistor Q4 is turned on, so that the base of the second NPN transistor Q3 is at a high level, so that the second NPN transistor Q3 is turned on. The second NPN transistor Q3 is turned on to reduce the base voltage of the first NPN transistor Q2, so that the first NPN transistor Q2 is turned off; the first NPN transistor Q2 is turned off to close the current loop between the emitter and the base of the first PNP transistor Q1, and the first PNP transistor Q1 is turned off to turn off the control module, so as to provide short-circuit protection for the load at the output end.

[0041] When the control module is turned off, the current passes through the indicator light D3, and the indicator light D3 lights up to remind relevant staff or equipment that the load is short-circuited.

[0042] When the positive electrode of the output terminal is connected to the load; the positive electrode of the capacitor C1 is connected to the emitter of the first NPN transistor Q2 through the first resistor R1 and the third resistor R3, and the base of the first NPN transistor Q2 is grounded through the fourth resistor R4, so that the first NPN transistor Q2 is turned on. The collector of the first NPN transistor Q2 is connected to the emitter of the first PNP transistor Q1 to turn on the first PNP transistor Q1 to start the control module; the first PNP transistor Q1 is turned on so that the input terminal supplies power to the output terminal through the diode D1 and the first PNP transistor Q1.

Claims

1. An output short-circuit protection circuit based on a voltage regulator tube, applied to a load, characterized in that: The circuit comprises: A rectifier module, used to convert the AC power at a preset input terminal into DC power; A control module, connected to the rectifier module, for controlling the DC power to be delivered to the load at a preset output terminal; A short-circuit protection control module is connected to the rectifier module and the control module, and is used to shut down the control module when the load is short-circuited.

2. The output short circuit protection circuit based on the voltage regulator tube according to claim 1 is characterized in that: The rectifier module includes a transformer, a capacitor and a diode; The transformer comprises a primary winding and a secondary winding; The primary winding of the transformer is connected to the input end, one end of the secondary winding of the transformer is grounded, and the other end of the secondary winding is connected to the positive electrode of the diode; The cathode of the diode is connected to the anode of the capacitor, and the cathode of the capacitor is grounded.

3. The output short circuit protection circuit based on the voltage regulator tube according to claim 2 is characterized in that: The short circuit protection control module includes a first NPN transistor, a second NPN transistor, a second PNP transistor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a voltage regulator and an indicator light; The base of the first NPN transistor is connected to one end of a fourth resistor, and the other end of the fourth resistor is grounded; The base of the second NPN transistor is grounded, the collector of the second NPN transistor is connected to one end of the first resistor, and the other end of the first resistor is connected to the positive electrode of the capacitor; The base of the second PNP transistor is connected to the positive electrode of the capacitor, the collector of the second PNP transistor is connected to one end of the sixth resistor, and the other end of the sixth resistor is connected to the emitter of the second NPN transistor; The emitter of the first NPN transistor is connected to one end of the third resistor, and the other end of the third resistor is connected to one end of the first resistor; The emitter of the second PNP transistor is connected to one end of a fifth resistor, and the other end of the fifth resistor is connected to the positive electrode of the capacitor; The emitter of the second PNP transistor is connected to the positive electrode of the indicator light, the negative electrode of the indicator light is connected to the negative electrode of the voltage regulator, the positive electrode of the voltage regulator is connected to one end of the second resistor, and the other end of the second resistor is connected to the positive electrode of the output end.

4. The output short circuit protection circuit based on the voltage regulator tube according to claim 3 is characterized in that: The control module is a first PNP transistor; The positive electrode of the capacitor is connected to the base of the first PNP transistor, the collector of the first PNP transistor is connected to the positive electrode of the output end, and the emitter of the first PNP transistor is connected to the collector of the first NPN transistor.

5. The output short circuit protection circuit based on the voltage regulator tube according to claim 4 is characterized in that: When the positive pole of the output terminal is grounded, the load is short-circuited; The voltage of the positive electrode of the capacitor is connected to the negative electrode of the voltage regulator tube through the fifth resistor and the indicator light, so that the voltage regulator tube breaks down in reverse.

6. The output short circuit protection circuit based on the voltage regulator tube according to claim 5, characterized in that: The reverse breakdown of the voltage regulator tube reduces the base voltage of the second PNP transistor; The base voltage of the second PNP transistor is greater than the emitter voltage of the second PNP transistor, so that the second PNP transistor is turned on.

7. The output short circuit protection circuit based on a voltage regulator tube according to claim 6, characterized in that: The second PNP transistor is turned on to make the base of the second NPN transistor a high level, so that the second NPN transistor is turned on.

8. The output short circuit protection circuit based on the voltage regulator tube according to claim 7 is characterized in that: The second NPN transistor is turned on to reduce the base voltage of the first NPN transistor, so that the first NPN transistor is turned off; The first NPN transistor is turned off to close the current loop between the emitter and the base of the first PNP transistor, and the first PNP transistor is turned off to turn off the control module.

9. The output short circuit protection circuit based on a voltage regulator tube according to claim 8, characterized in that: When the positive pole of the output terminal is connected to the load; The positive electrode of the capacitor is connected to the emitter of the first NPN transistor through the first resistor and the third resistor, and the base of the first NPN transistor is grounded through the fourth resistor to turn on the first NPN transistor.

10. The output short circuit protection circuit based on a voltage regulator tube according to claim 9, characterized in that: The collector of the first NPN transistor is connected to the emitter of the first PNP transistor to turn on the first PNP transistor, so as to start the control module; The first PNP transistor is turned on so that the input end supplies power to the output end through the diode and the first PNP transistor.

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