A starter protector with voltage-sensing temperature detection

Abstract

This invention discloses a voltage-sensing temperature starter protector, comprising: a microcontroller module for detecting voltage and starting signals, calculating the starter's internal temperature based on conduction time, and achieving precise over-temperature protection; a power supply module electrically connected to the car battery and other functional modules, providing a stable power supply to each module; a power supply voltage sampling module for acquiring the real-time power supply voltage of the battery and transmitting it to the microcontroller module, which implements over-voltage and under-voltage protection based on the acquired power supply voltage; and over-temperature protection of the starter by detecting the voltage on the starter bus and calculating the starter's internal temperature. By using the microcontroller to detect voltage, the starter's status is monitored, resulting in more accurate judgment of starting and temperature status and a faster response time.

Description

Technical Field

[0001] This invention relates to the field of starter protector technology, specifically a starter protector that detects temperature by voltage. Background Technology

[0002] The starter motor is a crucial component of gasoline-powered vehicles, controlled by the driver via a switch to start the engine. In frigid weather, the challenge for the starter motor is immense. Due to factors such as increased oil viscosity and increased friction in engine components at low temperatures, starting resistance increases. To overcome this resistance, more torque than at normal temperatures is required. Increasing torque necessitates a larger starting current from the starter motor.

[0003] Based on the above application scenarios, starter motors are more prone to overheating and burnout under high starting currents. Therefore, an overheat protection device is needed to reduce the starter motor failure rate.

[0004] There are currently two solutions:

[0005] 1. Adding a temperature switch to the starter relay prevents the relay from operating when the starter motor overheats, thus providing overheat protection. The temperature switch is a mechanical device; at low temperatures, the two connecting pieces are conductive; at high temperatures, due to the different coefficients of thermal expansion, the two connecting pieces separate, achieving the purpose of disconnection. However, this principle is not sensitive to temperature detection; sometimes the starter motor has already burned out before the temperature switch activates, failing to achieve the intended protection.

[0006] 2. Using a temperature sensor, the starter relay is controlled to operate by detecting the temperature on the sensor. High-precision, fast-response temperature sensors are expensive and require a microcontroller to monitor the temperature. Ordinary temperature sensors are slow to respond and fail to achieve the desired control.

[0007] Therefore, a starter protector that detects temperature by voltage is proposed. Summary of the Invention

[0008] The purpose of this invention is to provide a starter protector that detects temperature by voltage, in order to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a starter protector with voltage-sensing temperature detection, comprising:

[0010] The microcontroller module is used to detect voltage and start signal, and calculate the internal temperature of the starter motor by the conduction time, so as to realize the precise over-temperature protection function.

[0011] The power module is electrically connected to the car battery and other functional modules to provide a stable power supply for each module.

[0012] The power supply voltage sampling module is used to collect the real-time power supply voltage of the battery and transmit it to the microcontroller module. The microcontroller module implements overvoltage protection and undervoltage protection based on the collected power supply voltage.

[0013] The ignition switch input is electrically connected to the car's ignition switch and is used to collect the ignition start signal and transmit it to the microcontroller module.

[0014] The 30b voltage sampling module has its sampling end connected to the input bus 30b of the automotive starter to collect the real-time voltage signal of the 30b bus and transmit it to the microcontroller module.

[0015] The programming interface is used to update the microcontroller's program;

[0016] The output control module receives control commands from the microcontroller module and executes the corresponding functions.

[0017] Preferably, the microcontroller module adopts an automotive-grade 8051 core 8-bit microcontroller U1, and the microcontroller U1 is connected to resistor R4, capacitor C4 and capacitor C3.

[0018] Preferably, the power module includes a power chip IC1, with a resistor R2, a diode D1, and a capacitor C1 connected to pins 1 and 3 of the power chip IC1 and connected to the car battery, and a capacitor C2 connected to pin 5 of the power chip IC1 and connected to the microcontroller U1.

[0019] Preferably, the power supply voltage sampling module includes resistors R5 and R9 connected in series. One end of resistor R5 is connected to the car battery, and one end of resistor R9 is grounded. The voltage divider node of resistors R5 and R9 is connected to capacitor C6 and connected to microcontroller U1.

[0020] Preferably, the ignition switch input module includes a resistor R8 and a resistor R10 connected in series. One end of the resistor R8 is electrically connected to the vehicle ignition switch. The voltage divider node of the resistors R8 and R10 is electrically connected to the microcontroller module. The other end of the resistor R10 is grounded. A capacitor C8 is connected in parallel between the resistors R8 and R10. A Zener diode ZD1 is connected in series between the resistors R8 and R10.

[0021] Preferably, the 30b voltage sampling module includes a resistor R6 and a resistor R11 connected in series. One end of the resistor R6 is connected to the starter 30b bus, and the other end of the resistor R11 is grounded. The voltage divider node of the resistors R6 and R11 is connected to a capacitor C7 and connected to the microcontroller U1.

[0022] Preferably, the output control module includes a driver chip U2. Pin 1 of the driver chip U2 is connected to a transistor Q1, a resistor R7, and a Zener diode ZD2. Pins 1 and 8 of the driver chip U2 are connected to a diode D2 and a capacitor C5. Pin 7 of the driver chip U2 is connected to the gate of a MOSFET Q2. The drain of the MOSFET Q2 is connected to the starter control circuit. The source of the MOSFET Q2 is connected to a freewheeling diode D3, and the other end of the freewheeling diode D3 is grounded.

[0023] Preferably, the programming interface is electrically connected to the programming port of the microcontroller module for online programming and updating of the microcontroller program.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. By detecting the voltage on the starter bus, the internal temperature of the starter can be calculated, thus achieving over-temperature protection of the starter.

[0026] 2. By detecting voltage through a microcontroller, the status of the starter motor is monitored, resulting in more accurate judgment of the starting status and temperature status, and a faster response speed.

[0027] 3. The protector is compatible with the functions of traditional relays and protectors. It replaces mechanical relays with electronic devices, reduces the use of non-ferrous metals, and can reduce weight by 90% compared to traditional relays.

[0028] 4. It has stronger EMC capabilities than mechanical relays and protectors, and can also provide reverse connection protection. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the protector of the present invention;

[0030] Figure 2 This is a circuit diagram of the power supply module of the present invention;

[0031] Figure 3 This is a circuit diagram of the microcontroller module of the present invention;

[0032] Figure 4 This is a circuit diagram of the power supply voltage sampling module of the present invention;

[0033] Figure 5 This is a circuit diagram of the ignition switch input module of the present invention;

[0034] Figure 6 This is a circuit diagram of the 30b voltage sampling module of the present invention;

[0035] Figure 7 This is a circuit diagram of the output control module of the present invention;

[0036] Figure 8This is a wiring diagram of the external circuit of the protector of the present invention. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0038] Please see Figure 1-8 This invention provides a technical solution: a voltage-sensing temperature starter protector, primarily used in the control and protection of automotive starters, with its peripheral wiring as follows... Figure 8 As shown, terminal 30 of the protector is connected to the positive terminal of the car battery, and terminal 30b is connected to the input bus of the starter motor.

[0039] The core components of this protector include a power supply module, a power supply voltage sampling module, an ignition switch input module, a 30B voltage sampling module, a microcontroller module, a programming interface, and an output control module.

[0040] Among them, such as Figure 1 As shown, the input terminal of the power module is connected to the positive terminal (30 terminal) of the car battery, and the output terminal is connected to the power supply terminals of the microcontroller module, the power supply voltage sampling module, the ignition switch input module, the 30b voltage sampling module, and the output control module, respectively, to convert the 12V / 24V voltage of the car battery into a stable 5V DC voltage and provide working power for each module.

[0041] like Figure 2 As shown, the power module includes an automotive-grade power chip IC1, a current-limiting resistor R2, a surge protector diode D1, an input filter capacitor C1, and an output filter capacitor C2. The battery input terminal V30 is connected to the input terminal of IC1 through the current-limiting resistor R2. The surge protector diode D1 is connected in reverse parallel between the input terminal of IC1 and ground. The input filter capacitor C1 is connected in parallel between the input terminal of IC1 and ground. The output filter capacitor C2 is connected in parallel between the output terminal of IC1 and ground. IC1 outputs a stable 5V voltage. The current-limiting resistor R2 limits the input current to prevent the power chip IC1 from burning out due to overcurrent. The surge protector diode D1 suppresses input surge voltage to prevent IC1 from being damaged by high voltage. C1 and C2 respectively filter the input and output voltages, ensuring power supply stability.

[0042] like Figure 3As shown, the microcontroller module uses an 8-bit microcontroller U1 with an automotive-grade 8051 core. The VDD5V pin of the microcontroller U1 is the 5V power supply terminal, and the VSS pin is the ground terminal. R4 and C4 form a reset circuit, which is connected to the RSTN reset port of U1. Pins P05 and P06 are the clock and data ports for ISP programming, which are connected to the programming interface module. Pin P13 is the control output terminal, which is connected to the signal input terminal of the output control module. Pin P06 is the ignition switch signal input terminal, which is connected to the ignition switch input module. Pin P07 is the 30-bit voltage sampling port, which is connected to the 30-bit voltage sampling module. Pins P12 and P11 are reserved ports, which can be used to expand temperature sampling and other functions.

[0043] like Figure 4 As shown, the power supply voltage sampling module includes voltage divider resistors R5 and R9 and filter capacitor C6. R5 and R9 are connected in series, with one end connected to the positive terminal V30 of the battery and the other end grounded. The voltage divider node is connected to the AD sampling port of the microcontroller U1. C6 is connected in parallel between the voltage divider node and ground to realize real-time acquisition of battery voltage and provide data basis for the overvoltage and undervoltage protection of the microcontroller.

[0044] like Figure 5 As shown, the ignition switch input module includes sampling resistors R8 and R10, a filter anti-jitter capacitor C8, and a surge suppression diode ZD1. R8 and R10 are connected in series, with one end connected to the ignition switch input terminal IN1 and the other end grounded. The voltage divider node is connected to the IO input port of the microcontroller U1. C8 is connected in parallel between the voltage divider node and ground, and ZD1 is connected in parallel between the voltage divider node and ground. C8 is used to filter out the jitter signal of the ignition switch to avoid false triggering, and ZD1 is used to suppress high voltage surges to protect the microcontroller IO port from damage.

[0045] like Figure 6 As shown, the 30b voltage sampling module includes voltage divider resistors R6 and R11 and filter capacitor C7. R6 and R11 are connected in series, with one end connected to the 30b bus of the starter motor and the other end grounded. The voltage divider node is connected to the AD sampling port of the microcontroller U1. C7 is connected in parallel between the voltage divider node and ground to achieve high-precision, real-time acquisition of the 30b bus voltage.

[0046] like Figure 7As shown, the output control module includes a driver chip U2, a power electronic switch MOSFET Q2, a freewheeling diode D3, a charge pump unit (D2, C5), and a buck power supply unit (R7, ZD2). The signal input terminal of the driver chip U2 is connected to the P13 control output terminal of the microcontroller U1, and the output terminal of the driver chip U2 is connected to the gate of Q2. Q2 is an automotive-grade N-channel MOSFET, with its drain connected to the starter motor 50 terminal control circuit and its source grounded. The freewheeling diode D3 is connected in reverse parallel between the drain and source of Q2 to release the induced energy of the starter motor electromagnetic switch coil when Q2 is turned off, preventing voltage spikes from damaging the device. D2 and C5 form a charge pump unit to provide a boost drive power supply for the driver chip U2, ensuring reliable conduction of the MOSFET Q2. R7 and ZD2 form a buck power supply unit to provide a stable operating power supply for the driver chip U2.

[0047] Working principle: After the driver closes the car ignition switch, the ignition switch input module collects the IGN start signal and transmits it to the microcontroller U1. After receiving the valid start signal, the microcontroller U1 outputs a control signal to the driver chip U2 through the P13 pin. The driver chip U2 drives the MOSFET Q2 to conduct, connecting the control circuit of the starter solenoid switch. The starter is powered on and starts to run, driving the engine to start.

[0048] While MOSFET Q2 is turned on, the microcontroller U1 collects the voltage value of the 30b bus in real time through the 30b voltage sampling module. Based on the known impedance of the starter circuit, the real-time operating current of the starter is calculated by the voltage difference between the 30b bus voltage and the battery voltage. The microcontroller U1 has a built-in preset starter current-temperature rise mathematical model. Based on the real-time operating current, the duration of current conduction, and the ambient temperature compensation parameters, the temperature value of the starter internal winding is calculated in real time.

[0049] When the calculated internal temperature of the starter reaches the preset over-temperature protection threshold, the microcontroller U1 immediately stops outputting control signals, controls the MOSFET Q2 to disconnect, cuts off the starter's control circuit, forces the starter to stop working, avoids the winding from overheating and burning out, and achieves precise over-temperature protection; only when the calculated temperature drops below the safety threshold and a new valid start signal is received will the MOSFET be allowed to be turned on again to resume starter operation.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A starter protector that detects temperature using voltage, characterized in that, include: The microcontroller module is used to detect voltage and start signal, and calculate the internal temperature of the starter motor by the conduction time, so as to realize the precise over-temperature protection function. The power module is electrically connected to the car battery and other functional modules to provide a stable power supply for each module. The power supply voltage sampling module is used to collect the real-time power supply voltage of the battery and transmit it to the microcontroller module. The microcontroller module implements overvoltage protection and undervoltage protection based on the collected power supply voltage. The ignition switch input is electrically connected to the car's ignition switch and is used to collect the ignition start signal and transmit it to the microcontroller module. The 30b voltage sampling module has its sampling end connected to the input bus 30b of the automotive starter to collect the real-time voltage signal of the 30b bus and transmit it to the microcontroller module. The programming interface is used to update the microcontroller's program; The output control module receives control commands from the microcontroller module and executes the corresponding functions.

2. A starter protector with voltage-detecting temperature according to claim 1, characterized in that: The microcontroller module uses an automotive-grade 8051 core 8-bit microcontroller U1, which is connected to resistor R4, capacitor C4 and capacitor C3.

3. A starter protector with voltage-detecting temperature according to claim 2, characterized in that: The power module includes a power chip IC1. Pins 1 and 3 of the power chip IC1 are connected to a resistor R2, a diode D1, and a capacitor C1 and are connected to a car battery. Pin 5 of the power chip IC1 is connected to a capacitor C2 and is connected to a microcontroller U1.

4. A starter protector with voltage-detecting temperature according to claim 2, characterized in that: The power supply voltage sampling module includes resistors R5 and R9 connected in series. One end of resistor R5 is connected to the car battery, and one end of resistor R9 is grounded. The voltage divider node of resistors R5 and R9 is connected to capacitor C6 and is connected to microcontroller U1.

5. A starter protector with voltage-detecting temperature according to claim 2, characterized in that: The ignition switch input module includes resistors R8 and R10 connected in series. One end of resistor R8 is electrically connected to the vehicle ignition switch. The voltage divider node of resistors R8 and R10 is electrically connected to the microcontroller module. The other end of resistor R10 is grounded. A capacitor C8 is connected in parallel between resistors R8 and R10. A Zener diode ZD1 is connected in series between resistors R8 and R10.

6. A starter protector with voltage-detecting temperature according to claim 2, characterized in that: The 30b voltage sampling module includes resistors R6 and R11 connected in series. One end of resistor R6 is connected to the 30b busbar of the starter motor, and the other end of resistor R11 is grounded. The voltage divider node of resistors R6 and R11 is connected to capacitor C7 and is connected to the microcontroller U1.

7. A starter protector with voltage-detecting temperature according to claim 1, characterized in that: The output control module includes a driver chip U2. Pin 1 of the driver chip U2 is connected to a transistor Q1, a resistor R7, and a Zener diode ZD2. Pins 1 and 8 of the driver chip U2 are connected to a diode D2 and a capacitor C5. Pin 7 of the driver chip U2 is connected to the gate of a MOSFET Q2. The drain of the MOSFET Q2 is connected to the starter control circuit. The source of the MOSFET Q2 is connected to a freewheeling diode D3, and the other end of the freewheeling diode D3 is grounded.

8. A starter protector with voltage-detecting temperature according to claim 1, characterized in that: The programming interface is electrically connected to the programming port of the microcontroller module and is used for online programming and updating of the microcontroller program.

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