Power lack prevention circuit for vehicle storage battery
By controlling the conduction and disconnection of the transistor using a Zener diode and a MOSFET, the problem of battery depletion caused by static power consumption in automobiles is solved. It realizes the automatic disconnection of the power supply circuit and the delay of data acquisition. The structure is simple and easy to maintain, and it has remote control capabilities.
Patent Information
- Application Number
- CN202423121602.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-18
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-12-18
AI Technical Summary
In existing technologies, the problem of battery depletion caused by static power consumption in automobiles, especially the inability to start the vehicle after a long period of parking, is addressed by existing solutions that rely heavily on software control, which increases the number of steps required for the driver and is not convenient enough.
The system employs a pure hardware solution, using a Zener diode and a MOSFET to control the switching on and off of the transistor, thereby automatically cutting off the power supply circuit. The ignition lock switch is used as a wake-up trigger to avoid additional driver intervention.
It achieves automatic power cut-off without adding driver operation steps, ensuring data acquisition completion and high-voltage component discharge sequence. It has a simple structure, is easy to maintain, and is feasible for remote control.
Smart Images
Figure CN223583846U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a circuit for preventing battery drain, and more particularly to a circuit for preventing battery drain in vehicle storage batteries. Background Technology
[0002] Currently, with the increasing number of automotive electronic control units (ECUs or VCUs) and varying capabilities in quiescent current management and network management, incidents of unexplained battery drain are becoming more frequent. When a car is parked for an extended period without use, excessive quiescent current from the body control unit or a certain load can lead to low battery charge, resulting in a battery drain and preventing the car from starting. Therefore, a protective measure is needed to prevent battery drain.
[0003] Currently, most vehicle battery depletion prevention measures rely on controllers and software to automatically cut off battery power or use recharging functions to prevent depletion. These methods do not employ purely hardware-based automatic power cutoff, thus adding extra steps for the driver and making use and maintenance inconvenient. Therefore, it is necessary to develop a purely hardware-based vehicle battery depletion prevention technology. Utility Model Content
[0004] Therefore, this utility model provides a vehicle battery anti-discharge circuit to solve the problem that the battery charge is too low to start the vehicle due to the static power consumption of the equipment caused by long-term parking.
[0005] To achieve the above objectives, this utility model provides the following technical solution: a vehicle battery anti-discharge circuit, including a battery body V1, a switch S1, a switch S2, a Zener diode T1, a Zener diode T2, a resistor R1A, a resistor R2A, a resistor R3A, a resistor R4A, a transistor Q1, and a MOSFET Q2.
[0006] The positive terminal of the battery body V1 is connected to one end of the switch S1, the other end of the switch S1 is connected to the source of the MOS transistor Q2, the drain of the MOS transistor Q2 is connected to one end of the resistor R4A, and the other end of the resistor R4A is connected to the negative terminal of the battery body V1.
[0007] The cathode of the Zener diode T1 is connected between the switch S1 and the source of the MOSFET Q2; the anode of the Zener diode T1 is connected to one end of the resistor R1A, and the other end of the resistor R1A is connected between the resistor R4A and the negative terminal of the battery body V1.
[0008] The cathode of the Zener diode T2 is connected to one end of the switch S2, and the other end of the switch S2 is connected between the switch S1 and the source of the MOSFET Q2; the anodes of the Zener diode T1 and the Zener diode T2 are both connected to one end of the resistor R2A, and the other end of the resistor R2A is connected to the base of the transistor Q1.
[0009] The collector of transistor Q1 is connected between one end of resistor R3A and the gate of MOSFET Q2; the other end of resistor R3A is connected between switch S1 and the source of MOSFET Q2; the emitter of transistor Q1 is connected between resistor R4A and the negative terminal of battery body V1.
[0010] As a preferred solution for the vehicle battery anti-discharge circuit, the transistor Q1 is an NPN type transistor;
[0011] When the base-emitter voltage difference of transistor Q1 is greater than 0.7V, the collector and emitter of transistor Q1 are connected to the circuit.
[0012] When the base-emitter voltage difference of transistor Q1 is not greater than 0.7V, the collector and emitter of transistor Q1 are open circuit.
[0013] As a preferred solution for the vehicle battery anti-discharge circuit, the MOSFET Q2 is a P-channel MOSFET;
[0014] When the gate-source voltage difference of the MOS transistor Q2 is less than 0V, the drain and source of the MOS transistor Q2 are connected.
[0015] When the gate-source voltage difference of the MOS transistor Q2 is not less than 0V, the drain and source of the MOS transistor Q2 are open-circuited.
[0016] As a preferred solution for the vehicle battery anti-discharge circuit, the value of the resistor R4A is the sum of all the vehicle's constant electrical loads.
[0017] As a preferred solution for the vehicle battery anti-discharge circuit, the negative terminal of the battery body V1, the resistor R1A, the emitter of the transistor Q1, and the resistor R4A are connected together and grounded.
[0018] This utility model has the following advantages: The positive terminal of the battery body V1 is connected to one end of the switch S1, the other end of the switch S1 is connected to the source of the MOSFET Q2, the drain of the MOSFET Q2 is connected to one end of the resistor R4A, and the other end of the resistor R4A is connected to the negative terminal of the battery body V1; the cathode of the Zener diode T1 is connected between the switch S1 and the source of the MOSFET Q2; the anode of the Zener diode T1 is connected to one end of the resistor R1A, and the other end of the resistor R1A is connected between the resistor R4A and the negative terminal of the battery body V1; the cathode of the Zener diode T2 is connected to the source of the MOSFET Q2; the anode of the Zener diode T1 is connected to one end of the resistor R1A, and the other end of the resistor R1A is connected between the resistor R4A and the negative terminal of the battery body V1; the cathode of the Zener diode T2 is connected to the source of the MOSFET Q2; the anode of the Zener diode T2 is connected to the source of the MOSFET Q2; the anode of the Zener diode T1 ... One end of switch S2 is connected to the switch, and the other end of switch S2 is connected between switch S1 and the source of MOSFET Q2; the anodes of Zener diode T1 and Zener diode T2 are both connected to one end of resistor R2A, and the other end of resistor R2A is connected to the base of transistor Q1; the collector of transistor Q1 is connected between one end of resistor R3A and the gate of MOSFET Q2; the other end of resistor R3A is connected between switch S1 and the source of MOSFET Q2; the emitter of transistor Q1 is connected between resistor R4A and the negative terminal of battery body V1. This invention achieves automatic power supply circuit cutoff using pure hardware; it does not require additional driver operation steps, using the ignition lock switch S2 as the wake-up trigger input; its structure and principle are simple, and maintenance is easy; it avoids the inability to start the vehicle due to low battery power; this invention does not directly cut off the low-voltage power supply upon power-off, thus ensuring: Ⅰ. Data acquisition equipment that requires a delayed power-off can complete data acquisition; Ⅱ. Some components have a longer high-voltage discharge period, ensuring that the high-voltage power-off is completed before the low-voltage power-off; Ⅲ. Because the low voltage is always present, it is feasible to install remote control equipment. Attached Figure Description
[0019] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the vehicle battery anti-discharge circuit structure provided in the embodiments of this utility model;
[0021] Figure 2 This is a schematic diagram of the first principle of the vehicle battery anti-discharge circuit provided in the embodiments of this utility model;
[0022] Figure 3 This is a schematic diagram of the second principle of the vehicle battery anti-discharge circuit provided in the embodiments of this utility model;
[0023] Figure 4This is a schematic diagram of the third principle of the vehicle battery anti-discharge circuit provided in the embodiments of this utility model. Detailed Implementation
[0024] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0025] See Figure 1 This utility model embodiment provides a vehicle battery anti-discharge circuit, including a battery body V1, switch S1, switch S2, Zener diode T1, Zener diode T2, resistor R1A, resistor R2A, resistor R3A, resistor R4A, transistor Q1 and MOSFET Q2.
[0026] Among them, the positive terminal of the battery body V1 is connected to one end of the switch S1, the other end of the switch S1 is connected to the source of the MOSFET Q2, the drain of the MOSFET Q2 is connected to one end of the resistor R4A, and the other end of the resistor R4A is connected to the negative terminal of the battery body V1.
[0027] Among them, the cathode of Zener diode T1 is connected between switch S1 and the source of MOSFET Q2; the anode of Zener diode T1 is connected to one end of resistor R1A, and the other end of resistor R1A is connected between resistor R4A and the negative terminal of battery body V1.
[0028] Among them, the cathode of Zener diode T2 is connected to one end of switch S2, and the other end of switch S2 is connected between switch S1 and the source of MOSFET Q2; the anodes of Zener diode T1 and Zener diode T2 are both connected to one end of resistor R2A, and the other end of resistor R2A is connected to the base of transistor Q1.
[0029] In this configuration, the collector of transistor Q1 is connected between one end of resistor R3A and the gate of MOSFET Q2; the other end of resistor R3A is connected between switch S1 and the source of MOSFET Q2; and the emitter of transistor Q1 is connected between resistor R4A and the negative terminal of battery body V1.
[0030] In this embodiment, transistor Q1 is an NPN transistor; when the base-emitter voltage difference of transistor Q1 is greater than 0.7V, the collector and emitter of transistor Q1 are connected; when the base-emitter voltage difference of transistor Q1 is not greater than 0.7V, the collector and emitter of transistor Q1 are disconnected; MOSFET Q2 is a P-channel MOSFET; when the gate-source voltage difference of MOSFET Q2 is less than 0V, the drain and source of MOSFET Q2 are connected; when the gate-source voltage difference of MOSFET Q2 is not less than 0V, the drain and source of MOSFET Q2 are disconnected.
[0031] In this embodiment, the value of resistor R4A is the sum of all constant electrical loads of the vehicle; the negative terminal of the battery body V1, resistor R1A, the emitter of transistor Q1, and resistor R4A are connected together and grounded.
[0032] The circuit principle of this utility model is as follows:
[0033] When the vehicle is parked for a long time and the battery power supply circuit is not physically cut off by switch S1, the characteristics of Zener diodes T1 and T2 are used to control the switching on and off of NPN transistor Q1 and P-channel MOSFET Q2 to realize the conduction or disconnection of the battery power supply circuit. The resistor R4A in the circuit is regarded as the sum of all constant electrical loads of the vehicle.
[0034] Specifically, when Zener diodes T1 and T2 are connected in reverse parallel to the circuit, if the voltage applied across Zener diodes T1 and T2 is lower than the breakdown voltage, Zener diodes T1 and T2 are in a high-impedance state and can be considered as an open circuit; if the voltage across Zener diodes T1 and T2 is greater than the breakdown voltage, Zener diodes T1 and T2 are in a breakdown state and can be considered as a closed circuit.
[0035] Among them, the base-emitter voltage difference (V) of NPN transistor Q1 BE When the voltage is greater than 0.7V, the collector and emitter can be simply understood as a closed circuit; conversely, they can be understood as an open circuit. The gate-source voltage difference (V) of the P-channel MOSFET Q2 is... GS When the voltage is less than 0V, the drain and source can be simply understood as a closed circuit; conversely, they can be understood as an open circuit. When the Zener diode T1 breaks down in reverse, or when the Zener diode T2 breaks down in reverse while the switch S2 is closed, the power supply circuit can be closed.
[0036] See Figure 2Considering the vehicle's discharge during parking as process 1, with switch S1 not disconnected during prolonged parking, the battery's voltage V1 begins to drop due to the presence of static current. The circuit checks if the battery's voltage V1 is greater than the breakdown voltage of the Zener diode T1. If the battery's voltage V1 is greater than the Zener diode T1's breakdown voltage, the circuit maintains a connection to supply power to the vehicle. If the battery's voltage V1 is lower than the Zener diode T1's breakdown voltage, V... BE When the voltage is less than 0.7V, the Zener diode T1 is not conducting, and the transistor Q1 is open, causing V to... GS =0V, MOSFET Q2 is also in the off state, the discharge process is completed, the power supply circuit is cut off, and only the battery body V1 is self-discharged.
[0037] See Figure 3 Process 2 involves discharging the battery body V1 to below the voltage alarm value and then powering it on again. The breakdown voltage (V) of the Zener diode T1 is then set. T1 The battery voltage alarm value is the breakdown voltage of the Zener diode T2 (V). T2 ) represents the battery voltage limit, V T1 >V T2 After the battery voltage drops below the alarm threshold and is cut off, powering on again will trigger the ignition lock switch S2 by turning the key. Since the battery voltage is cut off at the alarm threshold, it will still be higher than the limit value V. T2 This can break down the Zener diode T2, causing transistor Q1 and MOSFET Q2 to conduct and complete the power-on process.
[0038] See Figure 4 Process 3 involves powering on the battery when its voltage V1 is at its normal state. At this time, the voltage V1 of the battery is higher than V. T1 and V T2 That is, the conduction conditions of transistor Q1 and MOSFET Q2 are met, and the closing of ignition lock switch S2 does not affect the state of the entire circuit.
[0039] In summary, this utility model includes a battery body V1, switches S1 and S2, Zener diodes T1 and T2, resistors R1A, R2A, R3A, and R4A, a transistor Q1, and a MOSFET Q2. The positive terminal of the battery body V1 is connected to one end of switch S1, and the other end of switch S1 is connected to the source of MOSFET Q2. The drain of MOSFET Q2 is connected to one end of resistor R4A, and the other end of resistor R4A is connected to the negative terminal of the battery body V1. The cathode of Zener diode T1 is connected between switch S1 and the source of MOSFET Q2. The anode of Zener diode T1 is connected to one end of resistor R1A. The other end is connected between resistor R4A and the negative terminal of battery body V1; the cathode of Zener diode T2 is connected to one end of switch S2, and the other end of switch S2 is connected between switch S1 and the source of MOSFET Q2; the anodes of Zener diode T1 and Zener diode T2 are both connected to one end of resistor R2A, and the other end of resistor R2A is connected to the base of transistor Q1; the collector of transistor Q1 is connected between one end of resistor R3A and the gate of MOSFET Q2; the other end of resistor R3A is connected between switch S1 and the source of MOSFET Q2; the emitter of transistor Q1 is connected between resistor R4A and the negative terminal of battery body V1. Consider the vehicle discharging during parking as process 1. With switch S1 not disconnected and the vehicle parked for an extended period, the battery voltage V1 begins to drop due to the presence of static current. The circuit checks if the battery voltage V1 is greater than the breakdown voltage of the Zener diode T1. If the battery voltage V1 is greater than the Zener diode T1 breakdown voltage, the circuit maintains a connection to supply power to the vehicle. If the battery voltage V1 is lower than the Zener diode T1 breakdown voltage, V... BE When the voltage is less than 0.7V, the Zener diode T1 is not conducting, and the transistor Q1 is open, causing V to... GS =0V, MOSFET Q2 is also in the off state, the discharge process is complete, the power supply circuit is cut off, and only the battery body V1 is self-discharged. Discharging the battery body V1 to below the voltage alarm value and then powering it on again is a process 2, setting the breakdown voltage of the Zener diode T1 (V T1 The battery voltage alarm value is the breakdown voltage of the Zener diode T2 (V). T2 ) represents the battery voltage limit, V T1 >V T2 After the battery voltage drops below the alarm threshold and is cut off, powering on again will trigger the ignition lock switch S2 by turning the key. Since the battery voltage is cut off at the alarm threshold, it will still be higher than the limit value V. T2 This can break down the Zener diode T2, causing transistor Q1 and MOSFET Q2 to conduct and complete the power-on process. Powering on the battery when its voltage V1 is at its normal state is considered process 3. At this time, the battery's voltage V1 is higher than V... T1 and V T2This means that the conduction conditions of transistor Q1 and MOSFET Q2 are met, and the ignition lock switch S2 being closed does not affect the overall circuit status. This invention uses pure hardware to automatically cut off the power supply circuit; it does not require additional driver operation steps, using the opening of the ignition lock switch S2 as the wake-up trigger input; the structure and principle are simple, and maintenance is easy; it avoids the inability to start the vehicle due to low battery power. This invention does not directly cut off the low-voltage power supply upon power-off, thus ensuring: Ⅰ. Data acquisition equipment that requires a delayed power-off can complete data acquisition; Ⅱ. Some components have a longer high-voltage discharge period, ensuring that the high-voltage power-off is completed before the low-voltage power-off; Ⅲ. Because the low voltage is always present, it is feasible to install remote control equipment.
[0040] Although the present invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.
Claims
1. A vehicle battery anti-discharge circuit, characterized in that, It includes the battery body V1, switch S1, switch S2, Zener diode T1, Zener diode T2, resistor R1A, resistor R2A, resistor R3A, resistor R4A, transistor Q1 and MOSFET Q2; The positive terminal of the battery body V1 is connected to one end of the switch S1, the other end of the switch S1 is connected to the source of the MOS transistor Q2, the drain of the MOS transistor Q2 is connected to one end of the resistor R4A, and the other end of the resistor R4A is connected to the negative terminal of the battery body V1. The cathode of the Zener diode T1 is connected between the switch S1 and the source of the MOSFET Q2; the anode of the Zener diode T1 is connected to one end of the resistor R1A, and the other end of the resistor R1A is connected between the resistor R4A and the negative terminal of the battery body V1. The cathode of the Zener diode T2 is connected to one end of the switch S2, and the other end of the switch S2 is connected between the switch S1 and the source of the MOSFET Q2; the anodes of the Zener diode T1 and the Zener diode T2 are both connected to one end of the resistor R2A, and the other end of the resistor R2A is connected to the base of the transistor Q1. The collector of transistor Q1 is connected between one end of resistor R3A and the gate of MOSFET Q2; the other end of resistor R3A is connected between switch S1 and the source of MOSFET Q2; the emitter of transistor Q1 is connected between resistor R4A and the negative terminal of battery body V1.
2. The vehicle battery anti-discharge circuit according to claim 1, characterized in that, The transistor Q1 is an NPN type transistor; When the base-emitter voltage difference of transistor Q1 is greater than 0.7V, the collector and emitter of transistor Q1 are connected to the circuit. When the base-emitter voltage difference of transistor Q1 is not greater than 0.7V, the collector and emitter of transistor Q1 are open circuit.
3. The vehicle battery anti-discharge circuit according to claim 1, characterized in that, The MOSFET Q2 is a P-channel MOSFET; When the gate-source voltage difference of the MOS transistor Q2 is less than 0V, the drain and source of the MOS transistor Q2 are connected. When the gate-source voltage difference of the MOS transistor Q2 is not less than 0V, the drain and source of the MOS transistor Q2 are open-circuited.
4. The vehicle battery anti-discharge circuit according to claim 1, characterized in that, The value of resistor R4A is the sum of all constant electrical loads of the vehicle.
5. The vehicle battery anti-discharge circuit according to claim 1, characterized in that, The negative terminal of the battery body V1, the resistor R1A, the emitter of the transistor Q1, and the resistor R4A are connected together and grounded.