A multifunctional relay protector

Abstract

The utility model discloses a multifunctional relay protector, which comprises an MCU module, the MCU module adopts a single-chip microcomputer IC1, a power module, the power module is connected with the MCU module, is used for realizing the voltage output of stable 5.1V, provides accurate reference voltage source for the ADC sampling of the single-chip microcomputer IC1, and the protector has the functions of delay protection, overrunning protection, top tooth protection and anti-reverse connection protection. When the ignition lock key cannot be automatically reset, the starting relay is stuck and fails to work, or the starting relay is accidentally turned on during jolting, etc., the protector can timely cut off the ignition circuit to protect the starter from being damaged. In addition, many relay protectors on the market have the phenomenon of high-voltage pulse failure. The protector of the present patent not only has various functions and stable working performance, but also has strong pulse resistance.

Description

Technical Field

[0001] This utility model relates to the field of relay protector technology, specifically a multifunctional relay protector. Background Technology

[0002] The starter motor is a key component of the car's starting system, converting electrical energy into mechanical energy to start the engine. All parts before the engine starts are driven by the starter motor, requiring a large starting current, typically above 100A. This large instantaneous current generates significant heat in the starter motor, causing considerable damage and sometimes even burning it out. Therefore, the market demand for starter motor protection devices is increasing, leading to the introduction of starter relay protectors. Surveys have found that only a small percentage of failures are truly caused by the starter motor itself; therefore, with continuous technological advancements and the development of intelligent systems, the market demand for this device will continue to grow.

[0003] Relays can control the large current entering the starter motor with a small current from the switch, protecting the solenoid switch and extending the starter motor's lifespan. However, when ignition key fails to reset automatically, the starter relay malfunctions due to sticking, or unexpected conduction occurs during vibration, the ignition circuit cannot disconnect properly. This can lead to accidents such as damage to the starter motor's drive gears, overheating and burning of the starter motor coils, premature battery failure, and fire. Existing relay protection devices are limited in function and expensive; therefore, we have designed a multi-functional relay protector. Summary of the Invention

[0004] The purpose of this invention is to provide a multifunctional relay protector to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a multifunctional relay protector, comprising:

[0006] MCU module, wherein the MCU module adopts a single-chip microcomputer IC1;

[0007] The power supply module is connected to the MCU module and is used to achieve a stable 5.1V voltage output, providing an accurate reference voltage source for the ADC sampling of the microcontroller IC1.

[0008] An ADC sampling module is connected to an MCU module and uses the voltage acquired by the ADC to achieve overrun protection.

[0009] The power transistor module is connected to the MCU module and is used to control the on / off state of the starter circuit according to the high and low potential output by the microcontroller IC1.

[0010] The reverse connection protection module is connected to the MCU module and is used to absorb the reverse induced electromotive force generated by the relay switch, so as to effectively protect the relay in the event of reverse connection.

[0011] Preferably, the power supply module includes a unidirectional diode D2, one end of which is connected to a 50C terminal, and the other end of which is connected to one end of a current-limiting resistor R1. The other end of the current-limiting resistor R1 is connected to one end of a Zener diode ZD1 and connected to pin 1 of the microcontroller IC1. The other end of the Zener diode ZD1 is grounded.

[0012] Preferably, the ADC sampling module includes a voltage divider resistor R1A and a voltage divider resistor R1B. One end of the voltage divider resistor R1A and one end of the voltage divider resistor R1B are both connected to pin 8 of the microcontroller IC1. The other end of the voltage divider resistor R1A is grounded, and the other end of the voltage divider resistor R1B is connected to the 50C terminal.

[0013] Preferably, the power transistor module includes a MOSFET Q1. The source of the MOSFET Q1 is connected to the negative terminal P3 of the battery and grounded. The drain of the MOSFET Q1 is connected to the negative terminal P2 of the relay coil. The gate of the MOSFET Q1 is connected to one end of a Zener diode ZD2, the collector of transistor Q2, and one end of a resistor R7. The other end of the Zener diode ZD2 and the emitter of transistor Q2 are grounded. The other end of the resistor R7 is connected to the 50C terminal. The base of transistor Q2 is connected to one end of a resistor R9 and one end of a resistor R8. The other end of the resistor R9 is grounded. The other end of the resistor R8 is connected to pin 9 of the microcontroller IC1.

[0014] Preferably, the reverse connection protection module includes a bidirectional transient suppression diode D1, which is connected between the 50C terminal and the negative terminal P2 of the relay coil.

[0015] Preferably, a resistor R11 and a capacitor C3 are connected to pin 4 of the microcontroller IC1, and a capacitor C1 and a capacitor C2 are connected between pins 1 and 14 of the microcontroller IC1.

[0016] Compared with existing technologies, the advantages of this invention are: the protector has time-delay protection, overrun protection, tooth-on-tip protection, and reverse connection protection functions. When faults such as the ignition key failing to reset automatically, the starter relay sticking and malfunctioning, or accidental conduction during vibration occur, the protector can promptly cut off the ignition circuit, protecting the starter motor from damage. Furthermore, many relay protectors on the market suffer from high-voltage pulse failure; this patented protector not only has diverse functions and stable performance but also strong anti-pulse capability. The protector controls the relay's on / off state via an MCU, and its functions can be implemented by modifying the program according to user needs, saving development costs and shortening the development cycle. It has wider applicability and a significant competitive advantage in a market that pursues high quality and fast pace. Attached Figure Description

[0017] Figure 1 This is a circuit block diagram of the present invention;

[0018] Figure 2 This is the circuit schematic diagram of this utility model;

[0019] Figure 3 This is the external wiring diagram of this utility model. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0021] Please see Figure 1-3 This utility model provides a technical solution: a multifunctional relay protector, including an MCU module, wherein the MCU module adopts a single-chip microcomputer IC1;

[0022] The power supply module is connected to the MCU module and is used to achieve a stable 5.1V voltage output, providing an accurate reference voltage source for the ADC sampling of the microcontroller IC1.

[0023] The ADC sampling module is connected to the MCU module and uses the voltage acquired by the ADC to achieve the overrun protection function.

[0024] The power transistor module is connected to the MCU module and is used to control the on / off state of the starter circuit based on the high and low potential output by the microcontroller IC1.

[0025] The reverse connection protection module is connected to the MCU module and is used to absorb the reverse induced electromotive force generated by the relay switch, effectively protecting the relay in the event of reverse connection.

[0026] The power module consists of a unidirectional diode D2, a current-limiting resistor R1, and a Zener diode ZD1. Diode D2 has a negative temperature coefficient, while Zener diode ZD1 has a positive temperature coefficient. By adding the diode for temperature compensation, a stable regulated output can be ensured over a wide temperature range, guaranteeing the stability of the microcontroller's power supply. The current-limiting resistor R1 controls the input current, protecting the microcontroller and the Zener diode for normal operation. The Zener diode ZD1 provides good consistency and stability in its voltage regulation, and when combined with the diode, it can achieve a stable 5.1V voltage output over a wide temperature range, providing an accurate reference voltage source for the microcontroller's ADC sampling. This power module offers strong voltage output stability and, compared to traditional voltage regulator chips, is cheaper, more adjustable, and more versatile.

[0027] The ADC sampling module consists of voltage divider resistors R1A and R1B. The microcontroller IC1 is an 8-bit controller with 8 ADC acquisition channels and 3 timers. The ADC sampling module uses ADC channel 6. The microcontroller IC1 implements overrun protection by acquiring the voltage at the 50C terminal of the ADC.

[0028] The specific implementation is as follows: The voltage at terminal 50C is divided by resistors R1B and R1A, resulting in a voltage value at pin 8 of microcontroller IC1. The ADC of microcontroller IC1 samples this voltage, performs analog-to-digital conversion, and obtains the voltage at terminal 50C. If microcontroller IC1 detects that the voltage at terminal 50C is greater than U1 for 30ms consecutively, it controls pin 9 to output a low potential. At this time, transistor Q2 is turned off, the relay's power transistor Q1 is turned on, the relay contacts close, and the starter motor begins to start the engine. During the starter motor startup process, microcontroller IC1 continues to monitor the voltage at terminal 50C. If it remains stable at U2 for 300ms consecutively, the overrun protection function of the relay protector is triggered. Pin 9 of microcontroller IC1 outputs a high potential, the relay protector's power transistor Q1 is turned off, the relay stops working, and the contacts open. Conversely, if pin 9 of microcontroller IC1 continues to output a low potential, the relay contacts remain closed, and the starter motor continues to drive the engine. When the microcontroller IC1 detects that the relay has been energized for a specified time T, the delay protection function of the relay protector will activate. Pin 9 of the microcontroller IC1 will output a high potential, the power transistor Q1 of the relay protector will turn off, the relay will stop working, the contacts will disconnect, and the starter will stop working.

[0029] The power transistor module consists of voltage divider resistors R8 and R9, transistor Q2, current-limiting resistor R7, Zener diode ZD2, and N-channel MOSFET Q1. When the starter motor completes startup or under abnormal conditions, the microcontroller's PIN9 outputs a high potential. Through the voltage divider resistors R8 and R9, Q2 conducts, preventing Q1 from turning on. This disconnects the starter motor's starting circuit, stopping the starter motor from working. During normal startup, the microcontroller's PIN9 outputs a low potential. Q2 does not conduct, but Q1 conducts, allowing the starter motor to operate normally. The power transistor Q1 in the power module has a withstand voltage of 200V, providing strong high-voltage resistance. Since the starter motor internally consists of a coil, which is an inductive component, a momentary high voltage occurs during starter motor switching. The selection of this power transistor fully considers the high-voltage pulse situation, enabling normal operation under momentary high voltage conditions and improving the reliability of the relay protector.

[0030] The reverse connection protection module consists of a bidirectional transient suppression diode D1. Sometimes, when installing relays, users mistakenly connect the relay's 50C terminal to the negative power supply and the negative terminal to the positive power supply. In such cases, relays without reverse connection protection will burn out, and in some cases, even the starter motor may be damaged. This invention addresses this problem by designing a reverse connection protection module that uses a bidirectional transient suppression diode instead of a conventional return current diode. It not only absorbs the reverse induced electromotive force generated during relay switching but also improves the reliability of the relay protector. Furthermore, in reverse connection situations, the bidirectional transient suppression diode D1 effectively protects the relay.

[0031] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A multifunctional relay protector, characterized in that, include: MCU module, wherein the MCU module adopts a single-chip microcomputer IC1; The power supply module is connected to the MCU module and is used to achieve a stable 5.1V voltage output, providing an accurate reference voltage source for the ADC sampling of the microcontroller IC1. An ADC sampling module is connected to an MCU module and uses the voltage acquired by the ADC to achieve overrun protection. The power transistor module is connected to the MCU module and is used to control the on / off state of the starter circuit according to the high and low potential output by the microcontroller IC1. The reverse connection protection module is connected to the MCU module and is used to absorb the reverse induced electromotive force generated by the relay switch, so as to effectively protect the relay in the event of reverse connection.

2. The multifunctional relay protector according to claim 1, characterized in that: The power module includes a unidirectional diode D2, one end of which is connected to a 50C terminal, and the other end of which is connected to one end of a current-limiting resistor R1. The other end of the current-limiting resistor R1 is connected to one end of a Zener diode ZD1 and connected to pin 1 of the microcontroller IC1. The other end of the Zener diode ZD1 is grounded.

3. A multifunctional relay protector according to claim 2, characterized in that: The ADC sampling module includes voltage divider resistors R1A and R1B. One end of voltage divider resistor R1A and one end of voltage divider resistor R1B are both connected to pin 8 of microcontroller IC1. The other end of voltage divider resistor R1A is grounded, and the other end of voltage divider resistor R1B is connected to terminal 50C.

4. A multifunctional relay protector according to claim 2, characterized in that: The power transistor module includes a MOSFET Q1. The source of the MOSFET Q1 is connected to the negative terminal P3 of the battery and grounded. The drain of the MOSFET Q1 is connected to the negative terminal P2 of the relay coil. The gate of the MOSFET Q1 is connected to one end of a Zener diode ZD2, the collector of transistor Q2, and one end of a resistor R7. The other end of the Zener diode ZD2 and the emitter of transistor Q2 are grounded. The other end of the resistor R7 is connected to the 50C terminal. The base of transistor Q2 is connected to one end of a resistor R9 and one end of a resistor R8. The other end of the resistor R9 is grounded. The other end of the resistor R8 is connected to pin 9 of the microcontroller IC1.

5. A multifunctional relay protector according to claim 4, characterized in that: The reverse connection protection module includes a bidirectional transient suppression diode D1, which is connected between the 50C terminal and the negative terminal P2 of the relay coil.

6. A multifunctional relay protector according to claim 1, characterized in that: The microcontroller IC1 has a resistor R11 and a capacitor C3 connected to pin 4, and a capacitor C1 and a capacitor C2 connected between pins 1 and 14 of the microcontroller IC1.

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