An electronic starting relay

Abstract

This application relates to an electronic starting relay, specifically within the technical field of relays. The electronic starting relay includes a bracket with a power supply terminal B+, an output terminal S, a signal input terminal, and a ground terminal E. The bracket integrates a control chip U1, a driver chip U2, an electronic switch Q1, and a power supply circuit. The input terminal of the power supply circuit is electrically connected to the power supply terminal B+, and the output terminal is electrically connected to both the control chip U1 and the driver chip U2. The signal input terminal is electrically connected to the control chip U1, and the control chip U1 is electrically connected to the driver chip U2. The input terminal of the electronic switch Q1 is electrically connected to the power supply terminal B+, the output terminal of the electronic switch Q1 is electrically connected to the output terminal S, and the control terminal of the electronic switch Q1 is electrically connected to the driver chip U2. This application enhances the vibration resistance and waterproof performance of the electronic starting relay, and provides overload and short-circuit protection, tooth top protection, timeout protection, secondary start protection, anti-drag protection, and a restart delay function.

Description

Technical Field

[0001] This application relates to the technical field of relays, and in particular to an electronic starting relay. Background Technology

[0002] The starting system of an automobile engine is a key component of the vehicle's powertrain. The starter relay, as an important actuator of the starting control system, is mainly used to connect or disconnect the high-current circuit between the battery and the starter motor through a low-power control signal sent by the starter switch, thereby driving the starter motor to rotate the engine crankshaft and start the engine.

[0003] Currently, most automotive starter relays are electromagnetic relays. Electromagnetic relays mainly consist of an electromagnetic coil, an armature, a return spring, and moving and stationary contacts. Their working principle is as follows: when the starter switch is turned on, the coil is energized, generating a magnetic field that attracts the armature, causing the contacts to close and thus connecting the starter motor power. When the starter switch is turned off, the coil is de-energized, the armature returns to its original position under the action of the spring, and the contacts open. Due to their simple structure and low cost, this type of electromagnetic relay was widely used in various types of gasoline-powered vehicles for a long time.

[0004] Regarding the aforementioned technologies, existing electromagnetic relays rely on the physical opening and closing of mechanical contacts. During frequent high-current switching processes, the contacts are prone to arc erosion, oxidation, or even adhesion, resulting in a service life of only tens of thousands of cycles. Furthermore, they have poor vibration resistance and are difficult to adapt to complex working conditions. Summary of the Invention

[0005] This application provides an electronic starting relay, the purpose of which is to improve the resilience of the starting relay under frequent switching conditions, extend the service life of the starting relay, enhance its vibration resistance and waterproof performance under complex working conditions, optimize the safety protection mechanism during the starting process, and reduce the risk of damage to the starter motor due to misoperation or failure.

[0006] The electronic starting relay provided in this application adopts the following technical solution: An electronic starting relay includes a bracket with a power supply terminal B+, an output terminal S, a signal input terminal, and a ground terminal E. The bracket integrates a control chip U1, a driver chip U2, an electronic switch Q1, and a power supply circuit. The input terminal of the power supply circuit is electrically connected to the power supply terminal B+, and the output terminal is electrically connected to both the control chip U1 and the driver chip U2. The signal input terminal is electrically connected to the control chip U1, and the control chip U1 is electrically connected to the driver chip U2. The signal input terminal receives a starting signal and transmits it to the control chip U1. The control chip U1 generates a drive signal based on the starting signal and transmits it to the driver chip U2. The input terminal of the electronic switch Q1 is electrically connected to the power supply terminal B+, the output terminal of the electronic switch Q1 is electrically connected to the output terminal S, and the control terminal of the electronic switch Q1 is electrically connected to the driver chip U2. The driver chip U2 controls the on / off state of the electronic switch Q1 based on the drive signal.

[0007] By adopting the above technical solution, an electronic starting relay structure based on all solid-state devices was constructed with the cooperation of the bracket, control chip, driver chip, electronic switch and power supply circuit.

[0008] When using this electronic starter relay, connect the starter switch or ECU to the signal input terminal, the vehicle power supply to the power terminal, and the starter motor's solenoid switch to the output terminal. When the starter switch or ECU issues a start command, the start signal enters through the signal input terminal and is transmitted to the control chip. After receiving the start signal, the control chip sends a drive signal to the drive chip, which then drives the electronic switch to conduct, thereby connecting the power terminal to the output terminal. This connects the vehicle power supply to the starter motor's solenoid switch, at which point the starter motor's solenoid switch closes, and the starter motor operates.

[0009] In this electronic starter relay, an electronic switch replaces the electromagnetic coil and mechanical contacts in existing electromagnetic relays. Because this electronic starter relay has no moving mechanical parts, it eliminates the problems of arcing, oxidation, and adhesion caused by frequent high-current switching of mechanical contacts, thus extending the service life of the electronic starter relay. Simultaneously, its lack of mechanical structure gives it higher vibration resistance, reducing the likelihood of malfunction when the vehicle is bumpy.

[0010] Optionally, the electronic switch Q1 is a MOSFET or an IGBT.

[0011] By adopting the above technical solutions, MOSFETs or IGBTs, as power semiconductor devices, possess characteristics such as fast switching speed, low on-resistance, and no mechanical noise. Especially for high-current starting circuits, MOSFETs or IGBTs enable precise on / off control and can withstand the high surge current during startup. Therefore, using MOSFETs or IGBTs in electronic switches can reduce power loss during high-current transmission, decrease device heat generation, and improve the continuous operating capability and stability of electronic starting relays under high-current conditions.

[0012] Optionally, the power supply circuit includes a boost circuit, the input terminal of which is electrically connected to the power supply terminal B+, and the output terminal of which is electrically connected to the driver chip U2. The boost circuit is used to boost the voltage at the power supply terminal B+ and provide a driving voltage for the driver chip U2.

[0013] By adopting the above technical solution, since electronic starting relays are generally connected in series between the power supply and the load, and when electronic switches use MOSFETs or IGBTs, the control terminal voltage must be higher than the input terminal voltage for the electronic switch to conduct. To address this, a boost circuit raises the voltage at the power supply terminals, providing the driver chip with a floating drive power supply higher than the power supply voltage. With this design, the driver chip can apply a sufficient voltage difference to the control terminal of the electronic switch, ensuring that the electronic switch can enter a deep saturation conduction state, thereby reducing on-resistance and heat generation, and preventing the electronic switch from burning out due to insufficient drive voltage operating in the linear amplification region.

[0014] Optionally, the boost circuit includes a fourth transistor Q4, a first resistor R1, a seventeenth resistor R17, a second diode D2, a third diode D3, a third capacitor C3, and a sixth capacitor C6; the emitter of the fourth transistor Q4 is electrically connected to the power supply terminal B+, the base of the fourth transistor Q4 is electrically connected to the control chip U1, the collector of the fourth transistor Q4 is electrically connected to the first terminal of the seventeenth resistor R17, and the second terminal of the seventeenth resistor R17 is electrically connected to the ground terminal E; the anode of the second diode D2 is connected to the... The power supply terminal B+ is electrically connected; the cathode of the second diode D2 is electrically connected to the anode of the third diode D3; the cathode of the third diode D3 is connected to the first terminal of the first resistor R1; the second terminal of the first resistor R1 is electrically connected to the driver chip U2; one end of the third capacitor C3 is electrically connected to the cathode of the second diode D2, and the other end is electrically connected to the collector of the fourth transistor Q4; one end of the sixth capacitor C6 is electrically connected to the second terminal of the first resistor R1, and the other end is electrically connected to the second terminal of the seventeenth resistor R17.

[0015] By adopting the above technical solution, in the design of the boost circuit, the fourth transistor is used to switch and oscillate under the control of the control chip. Combined with the pull-down effect of the seventeenth resistor and the charging and discharging characteristics of the third capacitor, and guided by the unidirectional conduction of the second and third diodes, charge is continuously pumped into the sixth capacitor. This structure utilizes the charge pump principle to achieve voltage multiplication, eliminating the need for large and expensive inductor components. This provides a stable high-voltage drive source for the driver chip in a low-cost, discrete device manner, which helps to reduce the size of the circuit board and lower production costs.

[0016] The working principle of the boost circuit is as follows: The control chip U1 outputs a PWM pulse signal to control the high-frequency switching of the fourth transistor Q4. When Q4 is off (charging phase), the seventeenth resistor R17 pulls the front end of the third capacitor C3 down to ground potential. The power supply B+ charges the third capacitor C3 through the second diode D2, making its voltage reach the power supply voltage value. When Q4 is on (boost phase), the power supply B+ is applied to the front end of the third capacitor C3 through Q4, making its potential instantly rise to the power supply voltage. Since the voltage across the capacitor cannot change abruptly, the potential at the rear end of the third capacitor C3 is boosted to approximately twice the power supply voltage. At this time, the second diode D2 is off, and the high potential forces the third diode D3 to conduct, transferring the charge to the sixth capacitor C6 for storage. Through this cyclical charging and discharging process, a stable voltage doubler is established across the sixth capacitor C6, providing sufficient high-side drive voltage for the driver chip U2, thus ensuring reliable saturation conduction of the electronic switch Q1 without the need for expensive inductor components.

[0017] Optionally, the signal input terminals include a first input terminal IN1 and a second input terminal IN2, wherein the first input terminal IN1 and the second input terminal IN2 are electrically connected to different pins on the control chip U1, respectively.

[0018] By adopting the above technical solution, two independent signal acquisition channels are provided for the control chip, enabling the control chip to monitor the level changes of the first input terminal and the second input terminal respectively. In this way, the difference in the level logic combination presented by the two input terminals under different external wiring methods can be used to directly identify whether the external start signal belongs to high-side drive (positive control) or low-side drive (negative control), thus realizing automatic compatibility with different polarity control logic.

[0019] Optionally, a third resistor R3 is connected in series between the first input terminal IN1 and the second input terminal IN2.

[0020] By employing the above technical solution, the third resistor establishes a current loop between the first and second input terminals. When the external starter switch or ECU is connected with different types of drive signals, such as positive power supply triggering or ground triggering, this current loop will cause the two input terminals to exhibit different level characteristics. The principle is as follows: when the external circuit is high-side driven (positive power supply triggering), the first input terminal is connected to a high level, the second input terminal is grounded, and the current forms a loop through the third resistor, and the control chip detects that the first input terminal is at a high level; when the external circuit is low-side driven (ground triggering), the first input terminal is connected to the power supply, and the second input terminal is pulled low to ground by the external switch. At this time, the third resistor acts as a load or pull-up resistor, and the control chip detects that the second input terminal is at a low level.

[0021] It is through the bridging effect of the third resistor, combined with the control chip's judgment of the combined potentials of the two terminals, that the same circuit structure can automatically adapt to and be compatible with two completely different control logics, high-side drive and low-side drive, without the need to change the hardware circuit.

[0022] Optionally, a feedback voltage detection circuit is also included. The feedback voltage detection circuit is electrically connected to the output terminal of the electronic switch Q1 and the control chip U1, respectively. The feedback voltage detection circuit is used to collect the voltage signal of the output terminal of the electronic switch Q1 and transmit the collected voltage signal to the control chip U1. The control chip U1 is used to determine and stop or start the output of the drive signal based on the acquired voltage signal.

[0023] By adopting the above technical solution and setting up a feedback voltage detection circuit, the control chip can acquire the real-time voltage status of the output terminal. Specifically, during startup, by combining the power supply voltage and the acquired output terminal voltage to calculate the voltage difference, the load current flowing through the electronic switch can be deduced. Based on the above information, the control chip can perform overload protection and short-circuit protection to prevent device burnout.

[0024] Optionally, the feedback voltage detection circuit includes a sixteenth resistor R16 and a fourth Zener diode DW4. The first end of the sixteenth resistor R16 is electrically connected to the output terminal of the electronic switch Q1, the second end of the sixteenth resistor R16 is electrically connected to the positive terminal of the fourth Zener diode DW4 and the control chip U1, and the negative terminal of the fourth Zener diode DW4 is electrically connected to the power supply terminal B+.

[0025] By adopting the above technical solution, in the feedback voltage detection circuit, the sixteenth resistor plays a current limiting role, converting the high voltage at the output terminal of the electronic switch into a detection signal acceptable to the control chip; the fourth Zener diode plays a key clamping protection role, absorbing the inductive back electromotive force or surge voltage generated at the moment the starter motor is de-energized, preventing high voltage pulses from damaging the detection pins of the control chip, and improving the circuit's anti-interference capability and reliability.

[0026] Optionally, a power supply voltage detection circuit is also included. The power supply voltage detection circuit is electrically connected to the power supply terminal B+ and the control chip U1 respectively. The power supply voltage detection circuit is used to collect the voltage signal of the power supply terminal B+ and transmit the collected voltage signal to the control chip U1. The control chip U1 is used to determine and stop or start the output of the drive signal based on the acquired voltage signal.

[0027] By adopting the above technical solution and setting up a power supply voltage detection circuit, the control chip can collect the real-time voltage status of the power supply terminals. Specifically, before starting, if the collected power supply voltage is higher than a preset threshold, it can be determined that the engine is already running; during the starting process, if a significant rise in power supply voltage or a specific ripple is detected, it can be determined that the engine has started successfully. Based on the above information, the control chip can execute anti-drag protection logic, promptly prohibiting or stopping the drive output, thereby preventing the starter gear from impacting or being dragged at high speed, effectively protecting the mechanical components of the starting system.

[0028] Optionally, the power supply voltage detection circuit includes a twentieth resistor R20 and a tenth resistor R10. The first end of the twentieth resistor R20 is electrically connected to the power supply terminal B+, the second end of the twentieth resistor R20 is electrically connected to the first end of the tenth resistor R10 and the control chip U1, and the second end of the tenth resistor R10 is electrically connected to the ground terminal E.

[0029] By adopting the above technical solution, the power supply voltage detection circuit is designed to reduce the high voltage of the vehicle power supply to the low voltage range allowed by the control chip by utilizing the principle of resistor voltage division, thereby ensuring that the control chip can safely and accurately acquire the power supply voltage signal.

[0030] In summary, this application includes at least one of the following beneficial technical effects: 1. This application replaces the electromagnetic coil and mechanical contact structure in the existing electromagnetic relay with an all-solid-state electronic switch. On the one hand, it eliminates the problems of arc erosion, contact oxidation and adhesion that are prone to occur in mechanical contacts during frequent high-current switching, thereby extending the service life of the electronic starter relay. On the other hand, the structural characteristic of having no mechanical moving parts makes the electronic starter relay have better vibration resistance, which can effectively prevent malfunctions when the vehicle is driving on bumpy roads, thus improving the reliability of the electronic starter relay.

[0031] 2. This application constructs an intelligent state recognition and protection mechanism based on voltage characteristics by controlling the voltage signals of the power supply terminals and output terminals in real time. On the one hand, it uses the amplitude and change characteristics of the power supply voltage to identify the engine's operating status, thereby prohibiting the output of drive signals to the already running engine before starting to achieve secondary start protection; after successful start, it quickly cuts off the drive signal to prevent the starter motor from being dragged in reverse to achieve anti-drag protection and prevent damage caused by starter motor overspeed. On the other hand, it uses the voltage difference between the power supply terminals and output terminals to calculate the real-time current status of the load circuit, and realizes top tooth protection based on whether the voltage difference decreases within a specified time. When an abnormal increase in voltage difference is detected, it quickly identifies short circuit or overload faults and forcibly shuts them off, realizing short circuit and overload protection, effectively preventing wiring harness fires or device burnouts caused by circuit faults, and making up for the lack of active safety protection mechanisms in existing electromagnetic starter relays.

[0032] 3. This application provides a floating drive power supply higher than the power supply voltage to the driver chip through a boost circuit, thereby ensuring that the electronic switch can quickly enter a deep saturation conduction state at the moment of startup, thereby reducing the conduction internal resistance and switching loss of the electronic switch, effectively preventing the electronic switch from being damaged due to excessive heat generation when operating in the linear region, and improving the stability of high current transmission. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the external wiring of the electronic starter relay, ECU, power supply, and starter motor of this application.

[0034] Figure 2 This is a circuit diagram showing the connection between the electronic starter relay and the starter motor of this application.

[0035] Figure 3 This is a circuit diagram of the internal control circuit of the electronic starting relay of this application.

[0036] Figure 4 This is a schematic diagram of the control chip U1 of this application.

[0037] Figure 5 This is a schematic diagram of the driver chip U2 of this application.

[0038] In the diagram, 100 is the signal input terminal; 200 is the signal input circuit; 300 is the power supply circuit; 301 is the voltage regulator circuit; 302 is the boost circuit; 303 is the drive voltage regulator circuit; 400 is the power supply voltage detection circuit; 500 is the feedback voltage detection circuit; 600 is the vehicle power supply; and 700 is the starter motor. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1 - Appendix Figure 5 This application will be described in further detail below.

[0040] An electronic starting relay, referenced Figure 1 and Figure 2 The system includes a bracket with a power supply terminal B+, an output terminal S, a signal input terminal 100, and a ground terminal E. A circuit board is housed within the bracket, integrating a control circuit that includes a signal input circuit 200, a control chip U1, a driver chip U2, an electronic switch Q1, and a power supply circuit 300.

[0041] Reference Figure 2 and Figure 3 The signal input terminal 100 is electrically connected to the input terminal of the signal input circuit 200, and the output terminal of the signal input circuit 200 is electrically connected to the control chip U1. The control chip U1 is electrically connected to the driver chip U2, the driver chip U2 is electrically connected to the control terminal of the electronic switch Q1, the input terminal of the electronic switch Q1 is electrically connected to the power supply terminal B+, and the output terminal of the electronic switch Q1 is electrically connected to the output terminal S. The input terminal of the power supply circuit 300 is electrically connected to the power supply terminal B+, and the output terminal of the power supply circuit 300 is electrically connected to both the control chip U1 and the driver chip U2.

[0042] In this embodiment, the rated operating voltage of the electronic starter relay is 12V. When using this electronic starter relay, refer to... Figure 1 Connect the starter switch or ECU to the signal input terminal 100, connect the vehicle power supply 600 to the power terminal B+, and connect the electromagnetic switch on the starter 700 to the output terminal S.

[0043] When power is applied to terminal B+, power supply circuit 300 supplies power to control chip U1 and drive chip U2, resetting them and putting them into standby mode. When the starter switch or ECU sends a start signal, the start signal enters signal input circuit 200 through signal input terminal 100. Signal input circuit 200 filters and conditions the start signal, then transmits the processed start signal to control chip U1. Upon receiving the start signal, control chip U1 transmits a drive signal to drive chip U2. After receiving the drive signal, drive chip U2 controls electronic switch Q1 to quickly saturate and conduct, thereby connecting power terminal B+ and output terminal S, energizing starter 700.

[0044] In this embodiment, when the control chip U1 is in standby mode, the static current of the circuit is less than 1.0mA.

[0045] Reference Figure 3 and Figure 4 The control chip U1 uses an 8-bit microcontroller, such as the PIC16F series or STM8S series and compatible chips. In this embodiment, the control chip U1 has a total of 14 pins, from pin 1 to pin 14 as follows: VDD pin, which is the positive power input terminal; RA5 pin, which is the drive control signal output terminal; RA4, RA3, RC3, RC4 and RC5 pins, which are reserved function terminals or programming interface terminals or reserved I / O ports; RC1 and RC2 pins, which are start signal detection input terminals; RC0 pin, which is the boost control signal output terminal; RA2 pin, which is the analog voltage detection input terminal; RA1 and RA0 pins, which are auxiliary detection terminals or debugging terminals; and VSS pin, which is the ground terminal.

[0046] Reference Figure 3 and Figure 5 The driver chip U2 uses a half-bridge driver or a high-side gate driver, such as IR2104, IRS2001, and compatible chips. In this embodiment, the driver chip U2 has a total of 8 pins, from pin 1 to pin 8: VCC pin, logic power input; HIN pin, high-side logic drive control input; LIN pin, low-side logic drive control input; COM pin, low-side loop common ground; LO pin, low-side gate drive output; VS pin, high-side floating power return; HO pin, high-side gate drive output; VB pin, high-side floating power input.

[0047] Reference Figure 3The signal input terminal 100 has two terminals, namely the first input terminal IN1 and the second input terminal IN2. The signal input circuit 200 includes a first circuit and a second circuit. The first input terminal IN1 is electrically connected to the input terminal of the first circuit, and the output terminal of the first circuit is electrically connected to the control chip U1. The second input terminal IN2 is electrically connected to the input terminal of the second circuit, and the output terminal of the second circuit is electrically connected to the control chip U1.

[0048] Specifically, refer to Figure 3 The first circuit includes an eleventh resistor R11, an eighteenth resistor R18, and an eighth capacitor C8. The first terminal of the eleventh resistor R11 is electrically connected to the first input terminal IN1, and the second terminal of the eleventh resistor R11 is electrically connected to the first terminal of the eighteenth resistor R18. The second terminal of the eighteenth resistor R18 is electrically connected to the ground terminal E. The eighth capacitor C8 is connected in parallel with the eighteenth resistor R18, and the second terminal of the eleventh resistor R11 is electrically connected to the RC1 pin of the control chip U1. The eleventh resistor R11 and the eighteenth resistor R18 form a voltage divider network to proportionally reduce the input high-level signal; the eighth capacitor C8 is used to filter out high-frequency interference in the signal.

[0049] Similarly, refer to Figure 3 The second circuit includes a twelfth resistor R12, a nineteenth resistor R19, and a ninth capacitor C9. The first end of the twelfth resistor R12 is electrically connected to the first input terminal IN1, the second end of the twelfth resistor R12 is electrically connected to the first end of the nineteenth resistor R19, the second end of the nineteenth resistor R19 is electrically connected to the ground terminal E, the ninth capacitor C9 is connected in parallel with the nineteenth resistor R19, and the second end of the twelfth resistor R12 is electrically connected to the RC2 pin of the control chip U1.

[0050] Reference Figure 3 The signal input circuit 200 also includes a third resistor R3, one end of which is electrically connected to the first input terminal IN1 and the other end is electrically connected to the second input terminal IN2.

[0051] With the design of the signal input circuit 200 and the first input terminal IN1 and the second input terminal IN2, this embodiment can be compatible with the starting control logic of various vehicle models. A current loop is formed between the first input terminal IN1 and the second input terminal IN2 through the third resistor R3, making the relay suitable not only for vehicles with high-side drive (starting signal is the positive power supply) but also for vehicles with low-side drive (starting signal is the ground signal). Simultaneously, the control chip U1, combined with dual-channel signal detection via the RC1 and RC2 pins, can employ differential signal judgment or dual verification logic to effectively filter out common-mode interference generated by wiring harness induction, prevent malfunction of the electronic starter relay, and improve the accuracy of signal recognition.

[0052] Reference Figure 3 The power supply circuit 300 includes a voltage regulator circuit 301, which includes a fifth transistor Q5, a second Zener diode DW2, a third Zener diode DW3, a second capacitor C2, a fourth capacitor C4, a ninth resistor R9, and a fourteenth resistor R14.

[0053] The fifth transistor, Q5, is a PNP type. The cathode of the third Zener diode, DW3, is electrically connected to the power supply terminal B+, and the anode of the third Zener diode, DW3, is connected to the emitter of the fifth transistor, Q5. The collector of the fifth transistor, Q5, is electrically connected to one end of the fourteenth resistor, R14, and the other end of the fourteenth resistor, R14, is electrically connected to ground, E. The cathode of the second Zener diode, DW2, is electrically connected to the cathode of the third Zener diode, DW3. The anode of the second Zener diode, DW2, is electrically connected to one end of the ninth resistor, R9, and the other end of the ninth resistor, R9, is electrically connected to ground, E. Simultaneously, the anode of the second Zener diode, DW2, is also electrically connected to the base of the fifth transistor, Q5.

[0054] The second capacitor C2, the fourth capacitor C4, and the third Zener diode DW3 are connected in parallel across the power supply pins of the control chip U1. Specifically, the cathode of the third Zener diode DW3, one end of the second capacitor C2, and one end of the fourth capacitor C4 are all electrically connected to the VDD pin of the control chip U1; the anode of the third Zener diode DW3, the other end of the second capacitor C2, and the other end of the fourth capacitor C4 are all electrically connected to the VSS pin of the control chip U1.

[0055] Reference Figure 3 The power supply circuit 300 also includes a boost circuit 302 and a drive voltage regulator circuit 303. The input terminal of the boost circuit 302 is electrically connected to the power supply terminal B+, the output terminal of the boost circuit 302 is electrically connected to the input terminal of the drive voltage regulator circuit 303, and the output terminal of the drive voltage regulator circuit 303 is electrically connected to the VB pin and VCC pin of the drive chip U2.

[0056] Reference Figure 3 The boost circuit 302 includes a fourth transistor Q4, a first resistor R1, a second resistor R2, a seventeenth resistor R17, a second diode D2, a third diode D3, a third capacitor C3, and a sixth capacitor C6.

[0057] The fourth transistor, Q4, is a PNP transistor. The first terminal of the second resistor R2 is electrically connected to the RC3 pin of the control chip U1, and the second terminal of the second resistor R2 is electrically connected to the base of the fourth transistor Q4. The first terminal of the seventeenth resistor R17 is electrically connected to the collector of the fourth transistor Q4, and the second terminal of the seventeenth resistor R17 is electrically connected to the ground terminal E. The emitter of the fourth transistor Q4 is electrically connected to the power supply terminal B+. The anode of the second diode D2 is electrically connected to the power supply terminal B+, and the cathode of the second diode D2 is electrically connected to the anode of the third diode D3. The cathode of the third diode D3 is connected to the first terminal of the first resistor R1, and the second terminal of the first resistor R1 is electrically connected to the input terminal of the drive voltage regulator circuit 303. One end of the third capacitor C3 is electrically connected to the cathode of the second diode D2, and the other end is electrically connected to the collector of the fourth transistor Q4. One end of the sixth capacitor C6 is electrically connected to the second terminal of the first resistor R1, and the other end is electrically connected to the second terminal of the seventeenth resistor R17.

[0058] The design of the boost circuit 302 forms a charge pump voltage multiplier circuit. When the control chip U1 controls the RC3 pin to output a pulse signal (PWM), when the RC3 pin outputs a low level, Q4 is turned on. The current output by the vehicle power supply 600 flows from the emitter to the collector of Q4, pulling the potential of the lower plate of C3 up to the power supply voltage. Since the voltage across the capacitor cannot change abruptly, the potential of the upper plate of C3 is instantaneously raised to approximately twice the power supply voltage. At this time, charge is injected into C6 through D3 and R1, providing high-voltage power to the driver chip U2. When the RC3 pin outputs a high level, Q4 is turned off, and the collector is pulled low to ground by R17. At this time, the vehicle power supply 600 charges C3 through D2. This cycle continues, providing the driver chip U1 with a drive voltage higher than the power supply voltage, thus ensuring that the driver chip U1 can drive the electronic switch Q1.

[0059] In this embodiment, the boost circuit 302 can operate normally within a power supply voltage range of 4.5V to 20.0V; the boost circuit 302 outputs the boosted high voltage to the driver chip U2 at a voltage value of 8.0V to 20.0V (ensuring that the high-side electronic switch Q1 can be driven to saturate and conduct).

[0060] Reference Figure 3 The driving voltage regulator circuit 303 includes a fifth resistor R5, a first Zener diode DW1, a second transistor Q2, and a fifth capacitor C5.

[0061] The second transistor Q2 is an NPN transistor. The collector of Q2 is electrically connected to the second terminal of the first resistor R1, and the emitter of Q2 is electrically connected to the VB and VCC pins of the driver chip U2. The first terminal of the fifth resistor R5 is electrically connected to the collector of Q2, and the second terminal of R5 is electrically connected to the base of Q2. The cathode of the first Zener diode DW1 is electrically connected to the base of Q2, and the anode of DW1 is electrically connected to the COM pin of the driver chip U2. The COM pin of the driver chip U2 is electrically connected to ground E, and ground E is grounded. The first terminal of the fifth capacitor C5 is electrically connected to the emitter of Q2, and the second terminal of C5 is electrically connected to the COM pin of the driver chip U2.

[0062] When the voltage output from the boost circuit 302 is applied to the collector of the second transistor Q2, current flows through R5 into the base of Q2, causing DW1 to reverse-biased and clamping the base voltage of Q2 to a preset reference voltage value (e.g., 16V to 20V, which must be higher than the sum of the voltage at the power supply terminal B+ and the threshold voltage of the electronic switch Q1). Utilizing the emitter follower characteristic of the NPN transistor, the emitter output voltage of Q2 is always slightly lower than the base voltage (approximately 0.7V lower), thus providing a stable DC voltage to the driver chip U2. C5 is used to filter out ripple in the output voltage. This circuit effectively prevents damage to the driver chip U2 due to excessively high or fluctuating output voltage from the boost circuit 302, ensuring stable operation of the driver chip U2 within a safe operating voltage range.

[0063] Reference Figure 3 The RA5 pin of the control chip U1 is electrically connected to the HIN pin of the driver chip U2.

[0064] In this embodiment, refer to Figure 3 A drive logic circuit is provided between the control chip U1 and the drive chip U2. The drive logic circuit includes the third MOS transistor Q3, the sixth resistor R6, the fourth resistor R4, and the fifteenth resistor R15.

[0065] The third MOSFET, Q3, is a P-channel enhancement-mode power MOSFET. The source of Q3 is electrically connected to the power supply terminal B+, and the drain is electrically connected to the first terminal of the fifteenth resistor R15. The second terminal of the fifteenth resistor R15 is electrically connected to ground E. The RA5 pin of the control chip U1 is electrically connected to the gate of the third MOSFET Q3. The first terminal of the sixth resistor R6 is electrically connected to the source of the third MOSFET Q3, and the second terminal of the sixth resistor R6 is electrically connected to the gate of the third MOSFET Q3. The HIN pin of the driver chip U2 is electrically connected to the first terminal of the fourth resistor R4, and the second terminal of the fourth resistor R4 is electrically connected to the drain of the third MOSFET Q3.

[0066] When the RA5 pin of the control chip U1 outputs a low level, Q3 is turned on, and the power supply voltage is applied to the HIN pin of the driver chip U2 through Q3 and R4, making its input high. When the RA5 pin outputs a high level, R6 pulls the gate of Q3 up to the source potential, Q3 is turned off, and R15 pulls the HIN pin down to ground, making the HIN pin input low. This allows the control chip U1 to effectively control the input level of the driver chip U2 using a low-voltage logic signal, realizing the level conversion from the logic level of the control chip U1 to the power supply voltage level, thereby ensuring that the driver chip U2 can reliably recognize the drive command.

[0067] Reference Figure 3 The electronic switch Q1 uses an N-channel enhancement-mode power MOSFET (MOS transistor) or an insulated-gate bipolar transistor (IGBT).

[0068] The input terminal of electronic switch Q1, i.e., the drain of the MOSFET or the collector of the IGBT, is electrically connected to the power supply terminal B+. The output terminal of electronic switch Q1, i.e., the source of the MOSFET or the emitter of the IGBT, is electrically connected to the output terminal S. The control terminal of electronic switch Q1, i.e., the gate of the MOSFET or the IGBT, is electrically connected to the HO pin of the driver chip U2. To prevent back electromotive force from damaging the circuit, a first diode D1 is connected in series between the output terminal S and the ground terminal E. The cathode of the first diode D1 is electrically connected to the output terminal S, and the anode is electrically connected to the ground terminal E.

[0069] In this embodiment, the on-resistance of electronic switch Q1 is less than 1.0mΩ, and the saturation voltage drop under a 200A load is less than 0.3V. The rated operating current of electronic switch Q1 is 400A, and the continuous current is 400A.

[0070] Reference Figure 3 The control circuit also includes a power supply voltage detection circuit 400. The power supply voltage detection circuit 400 includes a twentieth resistor R20, a tenth resistor R10, and a seventh capacitor C7. The first end of the twentieth resistor R20 is electrically connected to the power supply terminal B+, the second end of the twentieth resistor R20 is electrically connected to the first end of the tenth resistor R10, the second end of the tenth resistor R10 is electrically connected to the ground terminal E, and the seventh capacitor C7 is connected in parallel with the twentieth resistor R20. The RA0 pin of the control chip U1 is electrically connected to the second end of the twentieth resistor R20.

[0071] Reference Figure 3The control circuit also includes a feedback voltage detection circuit 500. The feedback voltage detection circuit 500 includes a sixteenth resistor R16 and a fourth Zener diode DW4. The cathode of the fourth Zener diode DW4 is connected to the power supply terminal B+, the anode of the fourth Zener diode DW4 is electrically connected to the first terminal of the sixteenth resistor R16, and the second terminal of the sixteenth resistor R16 is electrically connected to the output terminal of the electronic switch Q1. The RA2 pin of the control chip U1 is electrically connected to the anode of the fourth Zener diode DW4.

[0072] The implementation principle of this application embodiment is as follows: When the driver places the start switch in the start position, a start signal is applied to the first input terminal IN1 and the second input terminal IN2. After being processed by the signal input circuit 200, the start signal is sent to the control chip U1. After receiving the start signal, the control chip U1 first verifies the validity of the signal using a software debouncing algorithm. That is, the control chip U1 determines whether the duration of the valid level exceeds a preset stabilization time threshold, which is preferably 20ms-50ms, to confirm it as a genuine start request.

[0073] After confirming the request is valid, the control chip U1 performs the following security verification checks: Undervoltage protection: Control chip U1 detects the voltage at power terminal B+. If the voltage is lower than the minimum operating threshold, it indicates that the vehicle power supply 600 is severely depleted or the power supply is abnormal. To prevent the electronic switch Q1 from exploding due to insufficient drive voltage entering the linear region, control chip U1 disables starting. In this embodiment, the minimum operating threshold is preferably 7.5V.

[0074] Secondary start protection: Control chip U1 reads the voltage value of the power supply terminal B+ through its RA0 pin. If control chip U1 detects that the power supply voltage is higher than the preset start threshold, it determines that the engine is already running. At this time, control chip U1 prohibits the output of start command to prevent the starter motor 700 gear from forcibly engaging when the engine is rotating at high speed. The start threshold, i.e., the secondary start lockout voltage, is preferably 13.8V.

[0075] Anti-drag protection: Control chip U1 monitors power supply voltage changes at high frequency via the RA0 pin. When the engine starts successfully and the generator begins to work, causing the system voltage to rise or a specific waveform to appear, control chip U1 immediately cuts off the output signal to prevent the starter motor 700 from being dragged by the engine. In this embodiment, the drag protection delay is 2.0s to 4.0s.

[0076] Overload and Short Circuit Protection: Control chip U1 compares the voltage difference between pins RA0 and RA2 (the difference between the voltage at power supply terminal B+ and the voltage at output terminal S), using the internal resistance of electronic switch Q1 when it is turned on as a sampling resistor. According to Ohm's law, this voltage difference between pins RA0 and RA2 directly reflects the magnitude of the current flowing through electronic switch Q1. This allows for real-time monitoring of the current flowing through electronic switch Q1. If control chip U1 detects an abnormally large increase in the voltage difference, the corresponding current flowing through electronic switch Q1 will exceed the overload current threshold, indicating an overload or short circuit. In this embodiment, the overload current threshold is 450A, and control chip U1 immediately forces the output to shut down. During the operation of starter 700, control chip U1 continuously monitors and protects the operating status.

[0077] Overload protection: Overload protection is achieved based on whether the current flowing through electronic switch Q1 decreases within a specified time. In this embodiment, the overload current threshold is 450A, and the time threshold is 400ms. Timeout protection: The timer inside control chip U1 accumulates the single start-up time. If control chip U1 detects that the continuous working time exceeds the preset safety threshold and the starter has not started successfully, control chip U1 will forcibly cut off the output and enter a locked state to prevent the starter 700 from overheating and burning out due to prolonged operation. Specifically, the preferred safety threshold is 26s.

[0078] Restart delay: If it is necessary to restart immediately after the start is terminated, the shutdown and restart delay set in the control chip U1 is 0.5s±0.25s.

[0079] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. An electronic starting relay, characterized in that, include: The bracket is provided with a power supply terminal B+, an output terminal S, a signal input terminal (100) and a ground terminal E; the bracket integrates a control chip U1, a driver chip U2, an electronic switch Q1 and a power supply circuit (300). The input terminal of the power supply circuit (300) is electrically connected to the power supply terminal B+, and the output terminal of the power supply circuit (300) is electrically connected to the control chip U1 and the driver chip U2. The signal input terminal (100) is electrically connected to the control chip U1, and the control chip U1 is electrically connected to the drive chip U2. The signal input terminal (100) is used to receive a start signal and transmit it to the control chip U1. The control chip U1 is used to generate a drive signal according to the start signal and transmit it to the drive chip U2. The input terminal of the electronic switch Q1 is electrically connected to the power supply terminal B+, the output terminal of the electronic switch Q1 is electrically connected to the output terminal S, and the control terminal of the electronic switch Q1 is electrically connected to the driver chip U2. The driver chip U2 is used to control the electronic switch Q1 to turn on and off according to the drive signal.

2. The electronic starting relay according to claim 1, characterized in that, The electronic switch Q1 uses a MOSFET or an IGBT.

3. An electronic starting relay according to claim 2, characterized in that, The power supply circuit (300) includes a boost circuit (302). The input terminal of the boost circuit (302) is electrically connected to the power supply terminal B+, and the output terminal of the boost circuit (302) is electrically connected to the driver chip U2. The boost circuit (302) is used to boost the voltage of the power supply terminal B+ and provide a driving voltage for the driver chip U2.

4. An electronic starting relay according to claim 3, characterized in that, The boost circuit (302) includes a fourth transistor Q4, a first resistor R1, a seventeenth resistor R17, a second diode D2, a third diode D3, a third capacitor C3, and a sixth capacitor C6. The emitter of the fourth transistor Q4 is electrically connected to the power supply terminal B+, the base of the fourth transistor Q4 is electrically connected to the control chip U1, the collector of the fourth transistor Q4 is electrically connected to the first end of the seventeenth resistor R17, and the second end of the seventeenth resistor R17 is electrically connected to the ground terminal E. The positive terminal of the second diode D2 is electrically connected to the power supply terminal B+, the negative terminal of the second diode D2 is electrically connected to the positive terminal of the third diode D3, the negative terminal of the third diode D3 is connected to the first end of the first resistor R1, and the second end of the first resistor R1 is electrically connected to the driver chip U2. One end of the third capacitor C3 is electrically connected to the negative terminal of the second diode D2, and the other end is electrically connected to the collector of the fourth transistor Q4; one end of the sixth capacitor C6 is electrically connected to the second terminal of the first resistor R1, and the other end is electrically connected to the second terminal of the seventeenth resistor R17.

5. An electronic starting relay according to claim 1, characterized in that, The signal input terminal (100) includes a first input terminal IN1 and a second input terminal IN2, and the first input terminal IN1 and the second input terminal IN2 are electrically connected to different pins on the control chip U1, respectively.

6. An electronic starting relay according to claim 5, characterized in that, A third resistor R3 is connected in series between the first input terminal IN1 and the second input terminal IN2.

7. An electronic starting relay according to claim 1, characterized in that, It also includes a feedback voltage detection circuit (500), which is electrically connected to the output terminal of the electronic switch Q1 and the control chip U1 respectively. The feedback voltage detection circuit (500) is used to collect the voltage signal of the output terminal of the electronic switch Q1 and transmit the collected voltage signal to the control chip U1. The control chip U1 is used to determine and stop or start the output of the drive signal based on the acquired voltage signal.

8. An electronic starting relay according to claim 7, characterized in that, The feedback voltage detection circuit (500) includes a sixteenth resistor R16 and a fourth Zener diode DW4. The first end of the sixteenth resistor R16 is electrically connected to the output terminal of the electronic switch Q1. The second end of the sixteenth resistor R16 is electrically connected to the positive terminal of the fourth Zener diode DW4 and the control chip U1. The negative terminal of the fourth Zener diode DW4 is electrically connected to the power supply terminal B+.

9. An electronic starting relay according to claim 1, characterized in that, It also includes a power supply voltage detection circuit (400), which is electrically connected to the power supply terminal B+ and the control chip U1 respectively. The power supply voltage detection circuit (400) is used to collect the voltage signal of the power supply terminal B+ and transmit the collected voltage signal to the control chip U1. The control chip U1 is used to determine and stop or start the output of the drive signal based on the acquired voltage signal.

10. An electronic starting relay according to claim 9, characterized in that, The power supply voltage detection circuit (400) includes a twentieth resistor R20 and a tenth resistor R10. The first end of the twentieth resistor R20 is electrically connected to the power supply terminal B+. The second end of the twentieth resistor R20 is electrically connected to the first end of the tenth resistor R10 and the control chip U1. The second end of the tenth resistor R10 is electrically connected to the ground terminal E.

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