Short circuit test and protection circuit for throttle valve motor detection system

Abstract

The utility model relates to the field of protection circuits, in particular to a short-circuit test and protection circuit for a throttle valve motor detection system, which is characterized by comprising a singlechip, a power supply protection circuit and a short-circuit detection circuit, the power supply protection circuit comprises a load resistor group and a control circuit which are connected between a system power supply and a motor power supply end. The detection circuit is a comparator circuit based on an operational amplifier, two input ends of the comparator circuit are reference voltage and motor power supply end voltage respectively, and an output end of the comparator circuit is processed by the output circuit and then is detected by the singlechip; when the throttle valve motor has a short-circuit fault, the output level of the output circuit is changed, the single-chip microcomputer receives the change and then controls the CRT end to output a low level, the field-effect transistor Q10 and the triode Q12 are cut off, and the current between the system power supply and the motor power supply end is changed to pass through the load resistor group, so that the current of the motor power supply end is reduced, and the fault caused by the fact that the system power supply is connected to the short-circuit circuit is avoided.

Description

Technical Field

[0001] The utility model relates to the field of circuits, in particular to a short-circuit test and protection circuit for a throttle motor detection system. Background Art

[0002] The electronic throttle control system is an advanced technology in automotive engine electronic control. As a core component of the intake system in gasoline and natural gas engines, the throttle valve primarily controls the flow of air or mixed gas into the engine, thereby impacting engine performance. Over extended use, the throttle valve can experience position sensor signal drift, return spring aging, carbon deposits, and foreign object jamming. In these cases, the ECU can only detect a serious fault. Minor faults or anomalies, if not promptly detected, can further impact engine performance, resulting in insufficient power and increased fuel consumption.

[0003] Existing throttle motor testing systems can automatically measure the throttle body sensor's response time, the ratio of the sensor's output voltage to the power supply voltage, and the performance of the angle sensor. However, a short circuit in the valve motor during testing can pose a significant safety hazard to the entire test equipment's power supply, potentially even damaging the system's power supply. Summary of the Invention

[0004] In order to solve the above problems, the utility model provides a short-circuit test and protection circuit for a throttle motor detection system, comprising a single-chip microcomputer, a power protection circuit and a short-circuit detection circuit;

[0005] The power protection circuit includes a load resistor group and a control circuit connected between the system power supply and the motor power supply terminal; the control circuit includes a field effect transistor Q10 and a transistor Q12, the drain of the field effect transistor Q10 is connected to the system power supply, the source is connected to the motor power supply terminal, and the gate is connected to the collector of the transistor Q12; the base of the transistor Q12 is connected to the CRT terminal of the single-chip computer via a resistor R24, and the emitter is grounded; a resistor R34 is also connected between the source of the field effect transistor Q10 and the collector of the transistor Q12;

[0006] The detection circuit is a comparator circuit based on an operational amplifier. The two input terminals of the comparator circuit are the reference voltage and the motor power supply terminal voltage respectively. The output terminal is processed by the output circuit and sent to the single-chip microcomputer for detection. When the throttle motor short-circuit fault occurs, the output circuit outputs a low level. After receiving the output, the single-chip microcomputer controls the CRT terminal to output a low level, the field effect transistor Q10 and the transistor Q12 are cut off, and the current between the system power supply and the motor power supply terminal is diverted to the load resistor group, thereby reducing the current of the motor power supply terminal.

[0007] Furthermore, the comparator circuit includes an operational amplifier U6, wherein the positive input terminal of the amplifier U6 is connected to the reference voltage circuit, the inverting input terminal is connected to the motor power supply voltage, the positive pole of the power supply is connected to the system power supply, and the negative pole is grounded.

[0008] Furthermore, the output circuit includes a resistor R31, a transistor Q13 and a resistor R32, one end of the resistor R31 is connected to the output end of the comparator circuit, and the other end is connected to the base of the transistor Q13, one end of the resistor R31 is connected to a high-level voltage, and the other end is connected to the collector of the transistor Q13, the collector of the transistor Q13 is connected to the detection end of the microcontroller, and the emitter is grounded.

[0009] Furthermore, the load resistor group is a plurality of resistors connected in series or in parallel.

[0010] In summary, the present invention has at least one of the following beneficial effects:

[0011] The utility model uses a load resistor group to isolate the system power supply from the throttle motor power supply VCC. When a short circuit is detected in the throttle motor, the load resistor group will be connected in series with the entire circuit to prevent the system power supply from burning out. At the same time, VCC will be quickly pulled down. Then, through the operational amplifier for level comparison, the operational amplifier output will produce a high level, Q13 will be turned on, and the low level generated by the collector of Q13 will be sent to the single-chip microcomputer for detection. The single-chip microcomputer will thus determine that a short circuit fault has occurred in the throttle motor. If the throttle motor is not short-circuited, as long as the single-chip microcomputer inputs a high level to CTR, Q12 will be turned on, and the MOS tube Q10 will be turned on, allowing the system power supply to be connected to the throttle motor power supply, completing subsequent testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is the circuit diagram of the utility model. DETAILED DESCRIPTION

[0013] The present invention will be described in further detail below with reference to the accompanying drawings. Example

[0014] This embodiment provides a short-circuit test and protection circuit for a throttle motor detection system. The remaining detection circuits and achievable functions of the traditional throttle motor detection system are not the focus of protection of this embodiment. Usually, the detection modules of the detection system share the same system power supply. This embodiment only improves the impact on the detection system power supply when the throttle motor is short-circuited.

[0015] like Figure 1As shown, this embodiment includes a single-chip microcomputer, a power protection circuit and a short-circuit detection circuit. The single-chip microcomputer is used to control the short-circuit protection and normal switching of this circuit; the power protection circuit is used to control the single-chip microcomputer to connect a load resistor between the system power supply and the motor power supply terminal when the throttle motor is short-circuited, so as to prevent the system power supply from being directly connected to the short-circuited throttle motor and burning it; the short-circuit detection circuit is used to detect the circuit status of the throttle motor and send the result to the single-chip microcomputer.

[0016] The power protection circuit includes a load resistor group and a control circuit. The load resistor group consists of several resistors connected in series or parallel. The control circuit includes a field-effect transistor (FET) Q10 and a transistor (Q12). FET Q10's drain is connected to the system power supply, its source is connected to the motor power supply, and its gate is connected to the collector of transistor Q12. The base of transistor Q12 is connected to the CRT terminal of the microcontroller via resistor R24, and its emitter is grounded. Resistor R34 is also connected between the source of FET Q10 and the collector of transistor Q12.

[0017] The short-circuit detection circuit is a comparator circuit based on an operational amplifier. The positive input of operational amplifier U6 is connected to a reference voltage circuit, which consists of resistors R29 and R30 connected in series. The other end of resistor R29 is connected to the reference voltage, and the other end of R30 is connected to ground. Resistor R29 should have a much larger resistance than resistor R30 to ensure that the voltage at the node between the two resistors approximates the reference voltage. It is also connected to the positive input of amplifier U6. The negative input of operational amplifier U6 is connected to the motor power supply voltage. The positive terminal of the power supply is connected to the system power supply, the negative terminal is grounded, and the output terminal is connected to the output circuit. The output circuit includes resistor R31, transistor Q13, and resistor R32. Resistor R31 has one end connected to the comparator circuit output and the other end connected to the base of transistor Q13. Resistor R31 has one end connected to a high-level voltage and the other end connected to the collector of transistor Q13. The collector of transistor Q13 is connected to the detection terminal of the microcontroller, and the emitter is grounded.

[0018] When the throttle motor short-circuit fault occurs, the motor power supply terminal is grounded, the voltage of the inverting input terminal of the operational amplifier U6 drops, and the output terminal outputs a high level, causing Q13 to turn on. The microcontroller detection terminal receives a low level. At this time, the microcontroller outputs a low level to the CRT terminal, the field effect tube Q10 and the transistor Q12 are cut off, and the current between the system power supply and the motor power supply terminal is changed to pass through the load resistor group, thereby reducing the current of the motor power supply terminal and protecting the detection system.

[0019] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A short-circuit test and protection circuit for a throttle motor detection system, characterized in that: Including single chip microcomputer, power protection circuit and short circuit detection circuit; The power protection circuit includes a load resistor group and a control circuit connected between the system power supply and the motor power supply terminal; the control circuit includes a field effect transistor Q10 and a transistor Q12, the drain of the field effect transistor Q10 is connected to the system power supply, the source is connected to the motor power supply terminal, and the gate is connected to the collector of the transistor Q12; the base of the transistor Q12 is connected to the CRT terminal of the single-chip computer via a resistor R24, and the emitter is grounded; a resistor R34 is also connected between the source of the field effect transistor Q10 and the collector of the transistor Q12; The detection circuit is a comparator circuit based on an operational amplifier. The two input terminals of the comparator circuit are a reference voltage and a motor power supply terminal voltage, respectively. The output terminal is processed by the output circuit and sent to the single-chip microcomputer for detection. When the throttle motor short-circuit fault occurs, the output level of the output circuit changes. After receiving the signal from the single-chip microcomputer detection terminal, the CRT terminal is controlled to output a low level, the field effect transistor Q10 and the transistor Q12 are cut off, and the current between the system power supply and the motor power supply terminal is changed to pass through the load resistor group, thereby reducing the current of the motor power supply terminal.

2. The short-circuit testing and protection circuit according to claim 1, wherein: The comparator circuit includes an operational amplifier U6, wherein the positive input terminal of the amplifier U6 is connected to the reference voltage circuit, the negative input terminal is connected to the motor power supply voltage, the positive pole of the power supply is connected to the system power supply, and the negative pole is grounded.

3. The short-circuit testing and protection circuit according to claim 1, wherein: The output circuit includes a resistor R31, a transistor Q13 and a resistor R32. One end of the resistor R31 is connected to the output end of the comparator circuit, and the other end is connected to the base of the transistor Q13. One end of the resistor R31 is connected to a high-level voltage, and the other end is connected to the collector of the transistor Q13. The collector of the transistor Q13 is connected to the detection end of the microcontroller, and the emitter is grounded.

4. The short-circuit testing and protection circuit according to claim 1, wherein: The load resistor group is a plurality of resistors connected in series or in parallel.

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