A controllable short-circuit self-locking circuit for vehicle controllers

Abstract

This invention discloses a controllable short-circuit self-locking circuit for a vehicle controller, comprising a drive circuit and a feedback protection circuit, wherein the drive circuit is connected to a load; it also includes a control circuit, and the control circuit is provided with an input level control terminal; when the input of the input level control terminal is high, the drive circuit drives the load; when a short-circuit fault occurs in the load, the drive circuit stops driving the load; when the short-circuit fault in the load is cleared, setting the input of the input level control terminal to a low-level narrow pulse, the drive circuit resumes driving the load. This invention, while retaining the load short-circuit protection function of existing circuits, achieves controllability of the circuit's drive state, and can be applied to the drive output port circuit of a controller, improving the reliability and safety of the controller hardware.

Description

Technical Field

[0001] This invention relates to a circuit structure, and more particularly to a controllable short-circuit self-locking circuit for use in vehicle controllers. Background Technology

[0002] like Figure 1 As shown, the short-circuit self-locking circuit in the prior art for vehicle controllers can turn off transistor Q2 in the event of a load short circuit, thereby protecting the circuit from damage. However, when the short-circuit fault is cleared, the circuit remains in the short-circuit protection state, so it cannot continue to drive the load and needs to be powered on to return to normal.

[0003] like Figure 2 The diagram shows another short-circuit self-locking circuit for a vehicle controller in the prior art. This circuit... Figure 1 The circuit shown has an added resistor R3. This allows for load short-circuit protection, and after the short-circuit fault is cleared, capacitor C1 can be discharged through resistors R3 and R2, causing transistor Q1 to turn off and transistor Q2 to turn on, restoring the circuit to normal driving state without requiring a power-on process. However, the presence of resistor R3 allows current to flow through the load when the circuit is not in driving mode, potentially causing load malfunctions and reducing reliability. Furthermore, in both circuits mentioned above, transistor Q2 is normally in a conducting state, and the on / off state of transistor Q2 in the driving circuit cannot be freely controlled, meaning the circuit is in an uncontrollable state. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a controllable short-circuit self-locking circuit for use in vehicle controllers.

[0005] The controllable short-circuit self-locking circuit for vehicle controllers described in this invention includes a drive circuit and a feedback protection circuit, wherein the drive circuit is connected to the load.

[0006] It also includes a control circuit, and the control circuit is provided with an input level control terminal;

[0007] When the input level control terminal is high, the driving circuit drives the load;

[0008] When a short-circuit fault occurs in the load, the drive circuit stops driving the load;

[0009] Once the short-circuit fault of the load is cleared, the input of the input level control terminal is set to a low-level narrow pulse, and the driving circuit resumes driving the load.

[0010] In the controllable short-circuit self-locking circuit for vehicle controllers described in this invention, the drive circuit includes a second capacitor and a second transistor connected in parallel.

[0011] One end of the second capacitor is connected to the gate of the second transistor and is connected to the positive terminal of the power supply through the first resistor;

[0012] The other end of the second capacitor is connected to the source of the second transistor and to the negative terminal of the power supply;

[0013] The drain of the second transistor is also connected to the positive terminal of the power supply through a third resistor.

[0014] In the controllable short-circuit self-locking circuit applied to a vehicle controller according to the present invention, the feedback protection circuit includes a first capacitor and a first transistor arranged in parallel;

[0015] One end of the first capacitor is connected to the gate of the first transistor, and is connected to the positive terminal of the power supply through a second resistor and a third resistor connected in series.

[0016] The other end of the first capacitor is connected to the source of the first transistor and to the negative terminal of the power supply;

[0017] The drain of the first transistor is also connected to the positive terminal of the power supply through a first resistor.

[0018] In the controllable short-circuit self-locking circuit applied to a vehicle controller according to the present invention, the control circuit includes a first diode and a second diode arranged in parallel;

[0019] The cathode of the first diode is connected to the cathode of the second diode and is connected to the input level control terminal.

[0020] The positive terminal of the first diode is connected in parallel to the gate of the first transistor;

[0021] The positive terminal of the second diode is connected in parallel to the gate of the second transistor.

[0022] The controllable short-circuit self-locking circuit for vehicle controllers described in this invention adds a level control terminal and two diodes to the existing circuit. By utilizing the unidirectional conductivity of the diodes and controlling the conduction and cutoff of the first and second transistors through the high and low level states of the level control terminal, the circuit achieves controllability of the driving state while retaining the load short-circuit protection function of the existing circuit. It can be applied to the drive output port circuit of the controller, improving the reliability and safety of the controller hardware. Attached Figure Description

[0023] Figure 1This is a schematic diagram of the structure of a short-circuit self-locking circuit used in vehicle controllers in the prior art;

[0024] Figure 2 This is a schematic diagram of another short-circuit self-locking circuit used in vehicle controllers in the prior art;

[0025] Figure 3 A schematic diagram of the controllable short-circuit self-locking circuit applied to a vehicle controller according to the present invention. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0027] The controllable short-circuit self-locking circuit for a vehicle controller described in this invention includes a drive circuit and a feedback protection circuit, wherein the drive circuit is connected to a load. It also includes a control circuit, which has an input level control terminal. When the input level control terminal is high, the drive circuit drives the load. When a short-circuit fault occurs in the load, the drive circuit stops driving the load; and when the short-circuit fault is cleared, setting the input level control terminal to a low-level narrow pulse allows the drive circuit to resume driving the load.

[0028] Specifically, such as Figure 3 As shown, the driving circuit includes a second capacitor C2 and a second transistor Q2 connected in parallel. One end 2 of the second capacitor C2 is connected to the gate 1 of the second transistor Q2 and is connected to the positive power supply VCC through a first resistor R1. The other end 1 of the second capacitor C2 is connected to the source 2 of the second transistor Q2 and is connected to the negative power supply GND. The drain 3 of the second transistor Q2 is also connected to the positive power supply VCC through a third resistor R_load.

[0029] Still Figure 3 As shown, the feedback protection circuit specifically includes a first capacitor C1 and a first transistor Q1 connected in parallel. One end 2 of the first capacitor C1 is connected to the gate 1 of the first transistor Q1 and is connected to the positive power supply VCC through a second resistor R2 and a third resistor R_load connected in series. The other end 1 of the first capacitor C1 is connected to the source 2 of the first transistor Q1 and is connected to the negative power supply GND. The drain 3 of the first transistor Q1 is also connected to the positive power supply VCC through the first resistor R1.

[0030] The control circuit includes a first diode D1 and a second diode D2 connected in parallel. The cathode 2 of the first diode D1 is connected to the cathode 2 of the second diode D2 and is connected to the input level control terminal (control). The anode 1 of the first diode D1 is connected in parallel to the gate 1 of the first transistor Q1; the anode 1 of the second diode D2 is connected in parallel to the gate 1 of the second transistor Q2.

[0031] The working process of the controllable short-circuit self-locking circuit applied to the vehicle controller, as described above, is as follows:

[0032] When the input level of the input level control terminal is low, both the first diode D1 and the second diode D2 are turned on, and the gate 1 of both the first transistor Q1 and the second transistor Q2 is pulled low. Therefore, both the first transistor Q1 and the second transistor Q2 are turned off, and no current flows into the drain 3 of the second transistor Q2. The circuit is in a state of no drive output.

[0033] When the input level of the input level control terminal is high, both the first diode D1 and the second diode D2 are turned off. Since the parameters of the resistors and capacitors connected to the gates of the first transistor Q1 and the second transistor Q2 are different (for example, the resistance of the first resistor R1 is 12K ohms, and the resistance of the second resistor R2 is 100K ohms; the capacitance of the first capacitor is 4.7nF, and the capacitance of the second capacitor is also 4.7nF), the charging speed of the second capacitor C2 is higher than that of the first capacitor C1. This results in the voltage of the second capacitor C2 being slightly higher than that of the first capacitor C1. Consequently, the second transistor Q2 turns on before the first transistor Q1, causing the voltage of the first capacitor C1 to decrease and the first transistor Q1 to tend to turn off. Conversely, this causes the voltage of the second capacitor C2 to increase. This series of positive feedback ultimately leads to the circuit stabilizing so that the first transistor Q1 is in the off state, while the second transistor Q2 is in the on state, allowing the circuit to drive the load normally.

[0034] If a short-circuit fault occurs in the load, the first capacitor C1 will be charged through the short-circuited load (i.e., the third resistor R_load) and the second resistor R2. At this time, the gate voltage of the first transistor Q1 increases, and the first transistor Q1 begins to conduct. Current will also flow through the first resistor R1. Meanwhile, the gate voltage of the second transistor Q2 begins to decrease, and the second transistor Q2 begins to turn off. During this process, the on-resistance of the second transistor Q2 also increases. The increase in the on-resistance of the second transistor Q2 will, in turn, further increase the charging current of the first capacitor C1, thereby accelerating the rise of the voltage of the first capacitor C1 and promoting the conduction process of the first transistor Q1. Since this is a positive feedback process, the final result is that the first transistor Q1 is saturated and conducting, while the second transistor Q2 is completely turned off, thus realizing the circuit protection function.

[0035] Once the short-circuit fault in the load is cleared, to restore the circuit's driving state, simply apply a low-level narrow pulse to the input level control terminal to discharge the charge from the first capacitor C1 and the second capacitor C2, thus restoring the circuit to its initial driving state.

[0036] The controllable short-circuit self-locking circuit for vehicle controllers described in this invention adds a level control terminal and two diodes to the existing circuit. This utilizes the unidirectional conductivity of the diodes and controls the conduction and cutoff of the first transistor Q1 and the second transistor Q2 through the high and low level states of the level control terminal. While maintaining the load short-circuit protection function of the existing circuit, it achieves controllability of the circuit's driving state. This circuit can be applied to the drive output port circuit of the controller, improving the reliability and safety of the controller hardware.

[0037] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A controllable short-circuit self-locking circuit applied to a vehicle controller, characterized in that, It includes a drive circuit and a feedback protection circuit, wherein the drive circuit is connected to the load; It also includes a control circuit, and the control circuit is provided with an input level control terminal; When the input level control terminal is high, the driving circuit drives the load; When a short-circuit fault occurs in the load, the drive circuit stops driving the load; When the short-circuit fault of the load is cleared, the input of the input level control terminal is set to a low-level narrow pulse, and the driving circuit resumes driving the load. The driving circuit includes a second capacitor and a second transistor connected in parallel; One end of the second capacitor is connected to the gate of the second transistor and is connected to the positive terminal of the power supply through the first resistor; The other end of the second capacitor is connected to the source of the second transistor and to the negative terminal of the power supply; The drain of the second transistor is also connected to the positive terminal of the power supply through a third resistor; The feedback protection circuit includes a first capacitor and a first transistor connected in parallel. One end of the first capacitor is connected to the gate of the first transistor, and is connected to the positive terminal of the power supply through a second resistor and a third resistor connected in series. The other end of the first capacitor is connected to the source of the first transistor and to the negative terminal of the power supply; The drain of the first transistor is also connected to the positive terminal of the power supply through a first resistor; The control circuit includes a first diode and a second diode connected in parallel. The cathode of the first diode is connected to the cathode of the second diode and is connected to the input level control terminal. The positive terminal of the first diode is connected in parallel to the gate of the first transistor; The positive terminal of the second diode is connected in parallel to the gate of the second transistor.

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