Power supply protection circuit and vehicle-mounted brake actuator
By using two PMOS tubes and auxiliary power control circuits in the vehicle brake actuator, efficient safety and automatic detection of power reverse connection protection are achieved, and low efficiency and data of power reverse connection protection in the prior art are solved. The loss problem improves power utilization and equipment reliability.
Patent Information
- Application Number
- CN202422896027.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-27
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-11-27
AI Technical Summary
Existing power reverse protection technology causes the output available operating voltage to decrease in low voltage systems, and fails to effectively protect voltages beyond the range, and the auxiliary power supply may cause loss of equipment data when it does not work properly.
Two PMOS tubes and auxiliary power control circuits are used to achieve reverse connection protection and automatic detection of auxiliary power through photocouplers and transistors, ensuring that the auxiliary power supply is powered when the main power supply is powered off and data loss is avoided.
Improves the safety and reliability of reverse power supply protection, reduces voltage loss, ensures the safety of equipment data, and improves the power utilization rate.
Smart Images
Figure CN222301425U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of power supply protection, in particular to a power supply protection circuit and a vehicle-mounted brake actuator. Background Art
[0002] In the vehicle-mounted brake actuator, power reverse connection protection is an important safety feature, which can prevent circuit damage caused by reverse polarity of the power supply, thereby protecting the entire circuit and components from damage, greatly improving the safety and reliability of the product. In the prior art, power reverse connection protection is often implemented by diodes, but diodes consume extra energy when working normally, which may cause the output available working voltage to decrease in low-voltage power supply systems, reducing the overall efficiency of the system. And the use of diodes to implement reverse connection protection can only achieve reverse connection protection within a specific range, and cannot provide effective protection for voltages outside the range. In addition, in order to avoid the loss of parameters in the vehicle-mounted brake actuator after the main power supply is powered off, the vehicle-mounted brake actuator is usually equipped with an auxiliary power supply, which is used to continue to power a small number of low-power devices in the vehicle-mounted brake actuator after the main power supply is powered off, so as to avoid device data loss. However, in the existing multi-power supply power protection circuit, regardless of whether the auxiliary power supply is working normally, as long as the main power supply is connected normally, the load will be powered, which may cause the auxiliary power supply to be forgotten to be connected, resulting in device data loss when the main power supply fails. To this end, it is necessary to design a new power protection solution that can solve the above technical problems. Utility Model Content
[0003] In order to overcome the deficiencies of the prior art, the purpose of the utility model is to provide a power protection circuit that can reduce the voltage loss of the reverse connection protection function, enhance the safety and reliability of the reverse connection protection, and reliably avoid device data loss.
[0004] In order to solve the above problems, the technical solution adopted by the utility model is as follows: a power protection circuit, including a PMOS tube Q1, a PMOS tube Q2 and an auxiliary power control circuit, the drain of the PMOS tube Q1 is connected to the positive electrode of the main power supply, the gate of the PMOS tube Q1 is connected to the negative electrode of the main power supply, the source of the PMOS tube Q1 is connected to the source of the PMOS tube Q2, the drain of the PMOS tube Q2 is connected to the load, the gate of the PMOS tube Q2 is connected to the negative electrode of the main power supply through the auxiliary power control circuit, the auxiliary power control circuit is connected in series between the auxiliary power supply and the load, the auxiliary power control circuit is used to control the auxiliary power supply to supply power to the load when the main power supply is powered off, and the auxiliary power control circuit includes two photoelectric couplers and two transistors, the photoelectric coupler The positive electrode of the input end of the photocoupler U1 is connected to the working voltage, the negative electrode of the input end of the photocoupler U1 is connected to the auxiliary power supply self-locking signal, one end of the output end of the photocoupler U1 is connected to the negative electrode of the main power supply, and the other end is connected to the collector of the transistor Q3 and the gate of the PMOS tube Q2, the emitter of the transistor Q3 is connected to the negative electrode of the main power supply, the base of the transistor Q3 and the base of the transistor Q4 are both connected to the auxiliary power supply, the emitter of the transistor Q4 is connected to the negative electrode of the main power supply, the collector of the transistor Q4 is connected to the negative electrode of the input end of the photocoupler U2, the positive electrode of the input end of the photocoupler U2 is connected to the auxiliary power supply, one end of the output end of the photocoupler U2 is connected to the working voltage, and the other end is grounded through the resistor R13, and the two ends of the resistor R13 are connected in parallel with the capacitor C14.
[0005] Compared with the prior art, the beneficial effect of the utility model is that: reverse connection protection is realized by two PMOS tubes. When the main power supply is reversed, the gate voltages of the two PMOS tubes are reversed relative to the source, so that the two PMOS tubes are cut off, the current cannot be turned on, and the power reverse connection protection of the subsequent load is realized. Since the on-resistance of the PMOS tube is very low, the voltage loss of the PMOS tube is small during normal operation, and the available voltage output of the power supply will not be affected, the utilization rate of the power supply can be improved, and the response speed is fast, which can improve the safety and reliability of reverse connection protection. The auxiliary power supply control circuit detects whether the auxiliary power supply is connected through two transistors Q3 and Q4. When the auxiliary power supply is connected, the transistor Q3 will be turned on, so that the gate of the PMOS tube Q2 can be connected to the negative pole of the main power supply, so that the PMOS tube Q2 can be turned on, avoiding that the load can work normally only after the main power supply is correctly connected, and forgetting to correctly connect the auxiliary power supply, resulting in device data loss when the main power supply fails. The auxiliary power control circuit isolates the control signal between the controller and the auxiliary power control circuit through two photocouplers. Regardless of the polarity of the main power supply, the photocoupler can effectively isolate the control signal to prevent the reverse connection of the main power supply from affecting the normal operation of the auxiliary power control circuit.
[0006] In the above power protection circuit, the gate of the PMOS tube Q1 is connected to the negative electrode of the main power supply through the resistor R2, and the resistor R10 and the TVS diode DW1 are connected in parallel between the source and the gate of the PMOS tube Q1.
[0007] In the above power protection circuit, the two ends of the PMOS tube Q1 and the resistor R2 are connected in parallel with a TVS diode TVS2 and an electrolytic capacitor C9.
[0008] In the above power protection circuit, a resistor R1 and a TVS diode DW2 are connected in parallel between the source and the gate of the PMOS tube Q2, and the gate of the PMOS tube Q2 is connected to the auxiliary power control circuit through a resistor R4.
[0009] The above power protection circuit further includes a common mode filter T1. The negative electrode of the main power supply is grounded through the common mode filter T1. The drain of the PMOS tube Q2 is connected to the load through the common mode filter T1.
[0010] In the above power protection circuit, the positive electrode of the input end of the photocoupler U2 is connected to the negative electrode of the diode D1 through the resistor R14 and the fuse F1, and the positive electrode of the diode D1 is connected to the auxiliary power supply.
[0011] In the above power protection circuit, resistors R3 and R11 are connected in series between the base of transistor Q3 and the base of transistor Q4, and the connection node of resistors R3 and R11 is connected to the negative electrode of the main power supply through resistors R9 and R7.
[0012] In the above-mentioned power protection circuit, the connection node of the resistor R9 and the resistor R7 is connected to the anode of the Zener diode D2, the cathode of the Zener diode D2 is connected to the connection node of the fuse F1 and the resistor R14, the cathode of the Zener diode D2 is also connected to the cathode of the TVS diode TVS1, and the anode of the TVS diode TVS1 is connected to the cathode of the main power supply.
[0013] A vehicle-mounted brake actuator comprises a main power supply and an auxiliary power supply, and also comprises the above-mentioned power supply protection circuit, wherein the main power supply and the auxiliary power supply are connected to a load via the power supply protection circuit. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 The circuit diagram of the power protection circuit of the embodiment of the utility model is shown in FIG. DETAILED DESCRIPTION
[0015] The embodiments of the present invention are described in detail below. Figure 1The embodiment of the utility model provides a power protection circuit, including a PMOS tube Q1, a PMOS tube Q2 and an auxiliary power control circuit. The drain of the PMOS tube Q1 is connected to the positive electrode of the main power supply, the gate of the PMOS tube Q1 is connected to the negative electrode of the main power supply, and the source of the PMOS tube Q1 is connected to the source of the PMOS tube Q2. The drain of the PMOS tube Q2 is connected to the load, and the gate of the PMOS tube Q2 is connected to the negative electrode of the main power supply through the auxiliary power control circuit. The auxiliary power control circuit is connected in series between the auxiliary power supply ACC and the load, and the auxiliary power control circuit is used to control the auxiliary power supply ACC to supply power to the load when the main power supply is powered off.
[0016] The power protection circuit uses two PMOS tubes to realize the reverse connection protection of the load. When the main power is connected correctly, the gate voltage of the two PMOS tubes is negative relative to the source, and the two PMOS tubes are turned on. The current output by the main power can be output to the load through the two PMOS tubes; when the main power is reversed, the gate voltage of the two PMOS tubes will be reversed relative to the drain, so that the two PMOS tubes are cut off, and the current output by the main power is cut off by the PMOS tube and cannot be output to the load, thereby realizing the reverse connection protection of the load. Since the on-resistance of the PMOS tube is very low when it is turned on, the voltage loss of the PMOS tube is very low during normal operation, so it will not affect the available voltage output by the power supply, which can improve the utilization rate of the power supply, and the response speed of the PMOS tube is fast, which can improve the safety and reliability of the reverse connection protection. When the main power is disconnected, the auxiliary power control circuit controls the auxiliary power supply ACC to continue to supply power to the load, and supplies power to a small number of low-power devices in the load to avoid device data loss.
[0017] Reference Figure 1In this embodiment, the auxiliary power supply control circuit includes two photocouplers and two transistors. The positive pole of the input end of the photocoupler U1 is connected to the working voltage of 3.3V, the negative pole of the input end of the photocoupler U1 is connected to the auxiliary power supply self-locking signal, one end of the output end of the photocoupler U1 is connected to the negative pole of the main power supply, and the other end is connected to the collector of the transistor Q3 and the gate of the PMOS tube Q2. The emitter of the transistor Q3 is connected to the negative pole of the main power supply, and the collector of the transistor Q4 is connected to the negative pole of the input end of the photocoupler U2. The positive pole of the input end of the photocoupler U2 is connected to the auxiliary power supply ACC, one end of the output end of the photocoupler U2 is connected to the working voltage, and the other end is grounded through a resistor R13, and the two ends of the resistor R13 are connected in parallel with a capacitor C14. The positive pole of the input end of the photocoupler U2 is connected to the negative pole of the diode D1 through a resistor R14 and a fuse F1, and the positive pole of the diode D1 is connected to the auxiliary power supply ACC. Resistors R3 and R11 are connected in series between the base of transistor Q3 and the base of transistor Q4, and the connection node of resistors R3 and R11 is connected to the negative electrode of the main power supply through resistors R9 and R7. The connection node of resistors R9 and R7 is connected to the positive electrode of Zener diode D2, and the negative electrode of Zener diode D2 is connected to the connection node of fuse F1 and resistor R14. The negative electrode of Zener diode D2 is also connected to the negative electrode of TVS diode TVS1, and the positive electrode of TVS diode TVS1 is connected to the negative electrode of the main power supply.
[0018] In the above auxiliary power control circuit, when the auxiliary power ACC is connected, the base of the transistor Q3 is applied with voltage by the auxiliary power ACC through the voltage stabilizing diode D2, and the transistor Q3 is turned on, so that the gate voltage of the PMOS tube Q2 is pulled down, so that the PMOS tube Q2 is turned on. If the main power supply is also connected correctly, the electric energy output by the main power supply will be output to the load through the PMOS tube Q1 and the PMOS tube Q2. When the auxiliary power supply is not connected or connected in reverse, since the transistor Q3 will not be turned on, the gate voltage of the PMOS tube Q2 will not be pulled down, so that the PMOS tube Q2 will not be turned on, and both the main power supply and the auxiliary power supply cannot supply power to the load, thereby avoiding forgetting to connect the auxiliary power supply correctly and avoiding the loss of device data after the main power supply fails due to the auxiliary power supply not being connected properly. At this time, the base of transistor Q4 is applied with voltage, transistor Q4 is turned on, and the photocoupler U2 is turned on. The ACC_T signal outputted from the output end of the photocoupler U2 to the controller is high level, which conveys to the controller that the auxiliary power supply is connected. The controller samples the voltage of the auxiliary power supply ACC, confirms the voltage of the auxiliary power supply ACC, and outputs a high level auxiliary power supply self-locking signal ACC_LOCK to the input end of the photocoupler U1, so that the photocoupler U1 is turned on, so that when the main power supply is cut off, the gate voltage of the PMOS tube Q2 will still be pulled down, so that the PMOS tube Q2 remains turned on, and the voltage outputted by the auxiliary power supply ACC continues to supply power to the load for a short time through the PMOS tube Q2, and supplies power to a small number of low-power devices in the load, avoiding device data loss. The photocoupler can ensure that the control signal can be effectively isolated regardless of the polarity of the main power supply.
[0019] Reference Figure 1 In this embodiment, in order to ensure that a stable output voltage can be provided to the load, the output end of the circuit is connected to the load through a common-mode filter T1 with two-way patches, the drain of the PMOS tube Q2 is connected to the positive electrode of the load through the common-mode filter, and the ground of the load is connected to the negative electrode of the main power supply through the common-mode filter.
[0020] Reference Figure 1 In this embodiment, the gate of the PMOS tube Q1 is connected to the negative electrode of the main power supply through the resistor R2, the source and gate of the PMOS tube Q1 are connected in parallel with the resistor R10 and the TVS diode DW1, and the two ends of the PMOS tube Q1 and the resistor R2 are connected in parallel with the TVS diode TVS2 and the electrolytic capacitor C9. The source and gate of the PMOS tube Q2 are connected in parallel with the resistor R1 and the TVS diode DW2, and the gate of the PMOS tube Q2 is connected to the auxiliary power supply control circuit through the resistor R4. The above resistors and TVS diodes are used for current limiting and voltage stabilization and amplitude limiting to ensure that the circuit is within the safe working range, and the electrolytic capacitor C9 is used to reduce noise interference and ensure the smoothness and anti-interference ability of the circuit.
[0021] The vehicle-mounted brake actuator of the embodiment of the utility model includes the above-mentioned power protection circuit, main power supply, auxiliary power supply and controller, and the main power supply and auxiliary power supply are connected to the load through the power protection circuit. The positive pole of the input end of the photocoupler U1 in the power protection circuit and one end of the output end of the photocoupler U2 are electrically connected to the controller, and feedback is given to the controller whether the auxiliary power supply ACC is connected, and the auxiliary power supply self-locking signal ACC_LOCK is output to the auxiliary power supply control circuit according to the voltage of the auxiliary power supply ACC. The vehicle-mounted brake actuator using the power protection circuit can improve the reliability of the vehicle-mounted brake actuator, and will not affect the available voltage of the power supply output during normal operation, which can improve the utilization efficiency of the power supply.
[0022] It should be noted that in the description of the present invention, if there are any orientation descriptions, such as up, down, front, back, left, right, etc., the orientations or positional relationships indicated are all based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and cannot be understood as a limitation on the present invention.
[0023] In the description of the present utility model, "several" means one or more, "more" means two or more, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used to distinguish the technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.
[0024] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.
[0025] The above-mentioned implementation modes are only preferred implementation modes of the present invention, and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.
Claims
1. A power protection circuit, comprising PMOS tubes Q1 and Q2, wherein the drain of the PMOS tube Q1 is connected to the positive electrode of the main power supply, the gate of the PMOS tube Q1 is connected to the negative electrode of the main power supply, the source of the PMOS tube Q1 is connected to the source of the PMOS tube Q2, the drain of the PMOS tube Q2 is connected to the load, and the gate of the PMOS tube Q2 is connected to the negative electrode of the main power supply, characterized in that: It also includes an auxiliary power supply control circuit, the gate of the PMOS tube Q2 is connected to the negative electrode of the main power supply through the auxiliary power supply control circuit, the auxiliary power supply control circuit is connected in series between the auxiliary power supply and the load, and the auxiliary power supply control circuit is used to control the auxiliary power supply to supply power to the load when the main power supply is powered off. The auxiliary power supply control circuit includes two photocouplers and two transistors, the positive electrode of the input end of the photocoupler U1 is connected to the working voltage, the negative electrode of the input end of the photocoupler U1 is connected to the auxiliary power supply self-locking signal, and one end of the output end of the photocoupler U1 is connected to the negative electrode of the main power supply. The first end of the transistor Q3 is connected to the collector of the transistor Q3 and the gate of the PMOS tube Q2, the emitter of the transistor Q3 is connected to the negative electrode of the main power supply, the base of the transistor Q3 and the base of the transistor Q4 are both connected to the auxiliary power supply, the emitter of the transistor Q4 is connected to the negative electrode of the main power supply, the collector of the transistor Q4 is connected to the negative electrode of the input end of the photoelectric coupler U2, the positive electrode of the input end of the photoelectric coupler U2 is connected to the auxiliary power supply, one end of the output end of the photoelectric coupler U2 is connected to the working voltage, and the other end is grounded through a resistor R13, and both ends of the resistor R13 are connected in parallel with a capacitor C14.
2. The power protection circuit according to claim 1, characterized in that: The gate of the PMOS tube Q1 is connected to the negative electrode of the main power supply through the resistor R2, and a resistor R10 and a TVS diode DW1 are connected in parallel between the source and the gate of the PMOS tube Q1.
3. The power protection circuit according to claim 2, characterized in that: The two ends of the PMOS tube Q1 and the resistor R2 are connected in parallel with a TVS diode TVS2 and an electrolytic capacitor C9.
4. The power protection circuit according to claim 1, characterized in that: A resistor R1 and a TVS diode DW2 are connected in parallel between the source and the gate of the PMOS tube Q2 , and the gate of the PMOS tube Q2 is connected to the auxiliary power supply control circuit via a resistor R4 .
5. The power protection circuit according to claim 1, characterized in that: It also includes a common mode filter T1. The negative electrode of the main power supply is grounded through the common mode filter T1. The drain of the PMOS tube Q2 is connected to the load through the common mode filter T1.
6. The power protection circuit according to claim 1, characterized in that: The positive electrode of the input end of the photocoupler U2 is connected to the negative electrode of the diode D1 through the resistor R14 and the fuse F1, and the positive electrode of the diode D1 is connected to the auxiliary power supply.
7. The power protection circuit according to claim 6, characterized in that: A resistor R3 and a resistor R11 are connected in series between the base of the transistor Q3 and the base of the transistor Q4 , and a connection node between the resistor R3 and the resistor R11 is connected to the negative electrode of the main power supply through the resistor R9 and the resistor R7 .
8. The power protection circuit according to claim 7, characterized in that: The connection node of resistor R9 and resistor R7 is connected to the anode of Zener diode D2, the cathode of Zener diode D2 is connected to the connection node of fuse F1 and resistor R14, the cathode of Zener diode D2 is also connected to the cathode of TVS diode TVS1, and the anode of TVS diode TVS1 is connected to the cathode of the main power supply.
9. A vehicle-mounted brake actuator, comprising a main power supply and an auxiliary power supply, characterized in that: It also includes a power protection circuit according to any one of claims 1 to 8, wherein the main power supply and the auxiliary power supply are connected to a load through the power protection circuit.