An electronic preheating relay for a diesel engine

Abstract

The present invention relates to an electronic preheating relay for a diesel engine, comprising a control box fixed on a metal plate, the control box being provided with a battery terminal, a load terminal and two input terminals, a control circuit being provided in the control box, the control circuit comprising a signal input unit, a single-chip control unit, a half-bridge control unit, a first voltage stabilizing circuit, a second voltage stabilizing circuit and an oscillation boosting unit, the single-chip control unit being further connected with a thermistor for detecting the temperature of an aluminum-based PCB board; the single-chip control unit can control the output of the load terminal by collecting input signals of the two input terminals and the temperature of the aluminum-based PCB board. The present invention can provide over-temperature, overload and short-circuit protection for the electronic preheating relay, as well as timing, uncontrolled circuit breaking and load dumping absorption functions, has the advantages of large current, small volume, light weight and low power consumption, and can ensure the reliable operation of the electronic preheating relay.

Description

Technical Field

[0001] The invention relates to a diesel engine starting control technology, in particular to an electronic preheating relay of a diesel engine. Background Art

[0002] When the diesel engine is cold started, even if the compression is sufficient, the injected fuel is not heated to the natural temperature due to the low temperature, so a preheating system must be used to improve the ignition performance. Before the engine is cold started, the starting preheating system heats the compressed air through the grid heater to improve the engine's starting performance. In a low temperature environment, the ECU issues a preheating command, the electronic preheating relay is turned on, and the grid heater circuit is connected. The grid heater is installed between the diesel engine intake pipe and the cylinder. The grid heater is powered on to heat the air in the intake manifold to improve the low-temperature starting performance of the diesel engine. After starting, the air will continue to be heated for a period of time according to the temperature of the coolant, thereby reducing the phenomenon of diesel engine deflagration and white smoke. For example, an electronic preheating relay disclosed in the publication number CN203747366U performs fault detection by adding a single-chip microcomputer and a current sensor. When the grid heater is short-circuited, it can automatically cut off the preheater power supply to ensure the normal operation of the preheating system; however, this electronic preheating relay lacks timing, overtemperature, and overload monitoring, and still cannot guarantee the reliable operation of the preheating system. Summary of the invention

[0003] The object of the present invention is to provide an electronic preheating relay for a diesel engine, so as to solve the problem that the existing electronic preheating relay lacks over-temperature and overload protection.

[0004] In order to solve the above problems, the present invention provides an electronic preheating relay for a diesel engine, comprising a control box fixed on a metal plate, the control box being provided with a battery terminal, a load terminal and two input terminals, the control box being provided with a control circuit, the control circuit comprising a signal input unit, a single-chip control unit, a half-bridge control unit, a first voltage stabilizing circuit, a second voltage stabilizing circuit and an oscillation boost unit, the signal input unit being connected to the two input terminals and the single-chip control unit, the first voltage stabilizing circuit being connected to the battery terminal and the single-chip control unit to supply power to the single-chip control unit, the second voltage stabilizing circuit being connected to the The battery terminal and the half-bridge control unit are connected to power the half-bridge control circuit; the oscillation boost unit is connected to the battery terminal and the half-bridge control unit, the half-bridge control unit is connected to a drive circuit, and the drive circuit is respectively connected to the battery terminal, the load terminal, and the half-bridge control unit to control the output of the load terminal; the single-chip control unit is also connected to a thermistor for detecting the temperature of the aluminum-based PCB board; the single-chip control unit can control the output of the load terminal by collecting the input signals of the two input terminals and the temperature of the aluminum-based PCB board to achieve overcurrent protection and short-circuit protection.

[0005] Further, the signal input unit includes a third resistor connected to the first input terminal and a second resistor connected to the second input terminal, a first resistor is arranged between the first input terminal and the second input terminal, the third resistor and the second resistor are grounded through a twenty-sixth voltage-dividing resistor and a twenty-fifth voltage-dividing resistor respectively, a wiring terminal connected to the single-chip microcomputer control unit is arranged between the third resistor and the twenty-sixth voltage-dividing resistor, and a wiring terminal connected to the single-chip microcomputer control unit is arranged between the second resistor and the twenty-fifth voltage-dividing resistor.

[0006] Furthermore, the single-chip microcomputer control unit includes a single-chip microcomputer chip connected to the first voltage stabilizing circuit and the signal input unit, one pin of the single-chip microcomputer chip is grounded through a sixteenth resistor, a temperature detection circuit is connected in parallel at both ends of the sixteenth resistor, and the temperature detection circuit includes a thirty-third resistor and the thermistor connected in series.

[0007] Furthermore, the half-bridge control unit includes a half-bridge controller connected to the single-chip microcomputer control unit, and the half-bridge controller is respectively connected to the second voltage stabilizing circuit, the oscillation boost unit, the drive circuit, and the load terminal.

[0008] Furthermore, the load terminal is also connected to a voltage detection circuit, which includes a thirty-first resistor connected to the load terminal, the thirty-first resistor is grounded through a twenty-third voltage-dividing resistor and a ninth voltage-dividing resistor, a fast voltage detection terminal connected to the single-chip control unit is provided between the twenty-third voltage-dividing resistor and the ninth voltage-dividing resistor, and an eighth capacitor is also connected in parallel at both ends of the ninth voltage-dividing resistor; the thirty-first resistor is also grounded through a thirty-tenth voltage-dividing resistor and a twenty-second voltage-dividing resistor, a slow voltage detection terminal connected to the single-chip control unit is provided between the thirty-tenth voltage-dividing resistor and the twenty-second voltage-dividing resistor, and a seventh capacitor is also connected in parallel at both ends of the twenty-second voltage-dividing resistor.

[0009] Further, the oscillation boost unit includes a fourth triode whose base is connected to the single-chip microcomputer control unit through an eleventh resistor, and a sixth triode connected to the single-chip microcomputer control unit through a tenth resistor, the emitter of the fourth triode is grounded, the emitter of the sixth triode is grounded, the collector of the fourth triode is connected to the battery terminal through a thirteenth resistor, and the collector of the fourth triode is also connected to the battery terminal through an eleventh capacitor, an eighth diode, and an eighteenth resistor connected in sequence; the collector of the sixth triode is connected to the battery terminal through a fourteenth resistor, and the collector of the sixth triode is also connected to the load terminal through a ninth capacitor, a tenth diode, a seventeenth resistor, and a second capacitor connected in sequence, and the load terminal is also connected to the collector of the sixth triode through a third voltage-stabilizing diode, an eighth resistor, a fifth diode, and a ninth capacitor connected in sequence, and the collector of the fourth triode is also connected to the load terminal through the eleventh capacitor, the ninth diode, and the second capacitor connected in sequence.

[0010] Furthermore, the driving circuit includes a first field effect transistor and a second field effect transistor connected to the battery terminal, and the first field effect transistor is connected in parallel with the second field effect transistor; the gates of the first field effect transistor and the second field effect transistor are respectively connected to the half-bridge control unit, the first field effect transistor is connected to the load terminal through two parallel fuses, and the second field effect transistor is connected to the load terminal through two parallel fuses; when the first field effect transistor or the second field effect transistor is out of control, the two fuses connected to the field effect transistor are melted to perform out-of-control circuit protection.

[0011] Furthermore, when the battery terminal voltage is higher than 40V and maintained for more than 2-20ms, the single chip control unit controls the first field effect transistor and the second field effect transistor to be turned on for 500ms to absorb the generator energy after the load dump through the grid heater.

[0012] Further, the first voltage stabilizing circuit includes a third transistor connected to the single-chip computer control unit through a thirty-fifth resistor, the emitter of the third transistor is connected to the thirty-fifth resistor, the collector of the third transistor is connected to the battery terminal through a twentieth resistor, and the base of the third transistor is connected to the battery terminal through a seventh resistor and a thirty-fourth resistor; the base of the third transistor is also connected to the thirty-fifth resistor through a first diode and a tenth capacitor, and the tenth capacitor is also connected in parallel with a twelfth capacitor.

[0013] Furthermore, the seventh resistor is connected to the battery terminal through the thirty-fourth resistor, and the seventh resistor is also grounded through the fourth voltage-dividing resistor and the twenty-fourth voltage-dividing resistor. A terminal RAO ​​connected to the microcontroller chip is provided between the fourth voltage-dividing resistor and the twenty-fourth voltage-dividing resistor to detect the voltage of the battery terminal.

[0014] Furthermore, the second voltage stabilizing circuit includes a fifth transistor connected to the half-bridge control unit through a sixth diode, the anode of the sixth diode is connected to the emitter of the fifth transistor, the collector of the fifth transistor is connected to the base through a sixth resistor, the base of the fifth transistor is grounded through a second voltage stabilizing diode, and the cathode of the sixth diode is grounded through a third capacitor.

[0015] The present invention has the following beneficial effects: the electronic preheating relay of the present application can protect the electronic preheating relay from overtemperature, overload, short circuit, and uncontrolled circuit breaking, and also has a timing function and a load dumping absorption function. It has the advantages of large current, small size, light weight, and low power consumption, and can ensure the reliable operation of the electronic preheating relay. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of an electronic preheating relay according to an embodiment of the present invention;

[0017] Figure 2 The figure is a schematic diagram of the circuit structure of the electronic preheating relay according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0019] like Figure 1 , Figure 2In one embodiment of the electronic preheating relay of the diesel engine of the present invention, the electronic preheating relay of the diesel engine includes a control box 002 fixed on a metal plate 001 for grounding, and the control box is provided with a battery terminal B+, a load terminal OUT and two input terminals IN1, IN2. A control circuit is provided in the control box 002, and the control circuit includes a signal input unit 100, a single-chip control unit 200, a half-bridge control unit 300, a first voltage stabilizing circuit 400, a second voltage stabilizing circuit 500 and an oscillation boost unit 600. The signal input unit is connected to the two input terminals IN1, IN2 and the single-chip control unit 200, and the first voltage stabilizing circuit 400 is connected to the battery terminal B+ and the single-chip control unit 200 as a single-chip control unit. The control unit 200 is powered by the second voltage stabilizing circuit 500, which is connected to the battery terminal B+ and the half-bridge control unit 300 to power the half-bridge control circuit 300; the oscillation boost unit 600 is connected to the battery terminal B+ and the half-bridge control unit 300, and the half-bridge control unit 300 is connected to a drive circuit 700, which is respectively connected to the battery terminal B+, the load terminal OUT, and the half-bridge control unit 300 to control the output of the load terminal OUT; the single-chip microcomputer control unit 200 is also connected to a thermistor R28 for detecting the temperature of the aluminum-based PCB board; the single-chip microcomputer control unit 200 can control the output of the load terminal OUT by collecting the input signals of the two input terminals IN1 and IN2 and the temperature of the aluminum-based PCB board to achieve overcurrent protection and short-circuit protection.

[0020] In the above embodiment, the electronic preheating relay of the diesel engine also has the following technical features: preferably, the signal input unit 100 includes a third resistor R3 connected to the first input terminal IN1 and a second resistor R2 connected to the second input terminal IN2; a first resistor R1 and a thirty-sixth resistor R36 are provided between the first input terminal IN1 and the second input terminal IN2; the third resistor R3 and the second resistor R2 are grounded through the twenty-sixth voltage-dividing resistor R26 and the twenty-fifth voltage-dividing resistor R25, respectively; a terminal RC1 connected to the single-chip control unit is provided between the third resistor R3 and the twenty-sixth voltage-dividing resistor R26; a terminal RC2 connected to the single-chip control unit is provided between the second resistor R2 and the twenty-fifth voltage-dividing resistor R25. Preferably, a fifth capacitor C5 is connected in parallel to both ends of the twenty-sixth voltage-dividing resistor R26, a sixth capacitor C6 is connected in parallel to both ends of the twenty-fifth voltage-dividing resistor R25, and both the twenty-sixth voltage-dividing resistor R26 and the twenty-fifth voltage-dividing resistor R25 are grounded through the thirty-second voltage-dividing resistor R32.

[0021] In the above embodiment, preferably, the single-chip microcomputer control unit 200 includes a single-chip microcomputer chip U1 connected to the first voltage stabilizing circuit and the signal input unit, the single-chip microcomputer chip U1 has pins such as RC1, RC2, RC3, RC4, RA0, RA1, RA2, RA3, RA4, RA5, etc., the pin RA4 of the single-chip microcomputer chip U1 is grounded through a sixteenth resistor R16, and a temperature detection circuit is connected in parallel at both ends of the sixteenth resistor R16, the temperature detection circuit includes a thirty-third resistor R33 and a thermistor R28 connected in series, preferably, the sixteenth resistor R16 and the single-chip microcomputer chip U1 are also connected to another pin RC4 of the single-chip microcomputer chip U1 through a twenty-ninth resistor R29.

[0022] In the above embodiment, preferably, the half-bridge control unit 300 includes a half-bridge controller U2 connected to the single-chip microcomputer control unit 200, and the half-bridge controller U2 is respectively connected to the second voltage stabilizing circuit 500, the oscillation boost unit 600, the drive circuit 700, and the load terminal OUT.

[0023] In the above embodiment, preferably, the load terminal OUT is also connected to a voltage detection circuit 800, and the voltage detection circuit 800 includes a thirty-first resistor R31 connected to the load terminal OUT, the thirty-first resistor R31 is grounded through the twenty-third voltage-dividing resistor R23 and the ninth voltage-dividing resistor R9, a voltage fast detection terminal RA1 connected to the single-chip microcomputer control unit 200 is provided between the twenty-third voltage-dividing resistor R23 and the ninth voltage-dividing resistor R9, and an eighth capacitor C8 is also connected in parallel at both ends of the ninth voltage-dividing resistor R9; the thirty-first resistor R31 is also grounded through the thirty-third voltage-dividing resistor R30 and the twenty-second voltage-dividing resistor R22, a voltage slow detection terminal RA2 connected to the single-chip microcomputer control unit 200 is provided between the thirty-third voltage-dividing resistor R30 and the twenty-second voltage-dividing resistor R22, and a seventh capacitor C7 is also connected in parallel at both ends of the twenty-second voltage-dividing resistor R22.

[0024] In the above embodiment, preferably, the oscillation boost unit 600 includes a fourth triode Q4 whose base is connected to the single-chip microcomputer control unit 200 through an eleventh resistor R11, a sixth triode Q6 connected to the single-chip microcomputer control unit 200 through a tenth resistor R10, the emitter of the fourth triode Q4 is grounded, the emitter of the sixth triode Q6 is grounded, the collector of the fourth triode Q4 is connected to the battery terminal B+ through a thirteenth resistor R13, and the collector of the fourth triode Q4 is also connected to the battery terminal B+ through an eleventh capacitor C11, an eighth diode D8, and an eighteenth resistor R18 connected in sequence; the sixth triode Q6 is connected to the battery terminal B+ through a thirteenth resistor R13, and the collector of the fourth triode Q4 is connected to the battery terminal B+ through an eleventh capacitor C11, an eighth diode D8, and an eighteenth resistor R18 connected in sequence; The collector of the transistor Q6 is connected to the battery terminal B+ through the fourteenth resistor R14, the collector of the sixth transistor Q6 is also connected to the load terminal OUT through the ninth capacitor C9, the tenth diode D10, the seventeenth resistor R17, and the second capacitor C2 which are connected in sequence, the load terminal OUT is also connected to the collector of the sixth transistor Q6 through the third voltage zener diode D3, the eighth resistor R8, the fifth diode D5, and the ninth capacitor C9 which are connected in sequence, and the collector of the fourth transistor Q4 is also connected to the load terminal OUT through the eleventh capacitor C11, the ninth diode D9, and the second capacitor C2 which are connected in sequence.

[0025] In the above embodiment, preferably, the driving circuit 700 includes a first field effect transistor Q1 and a second field effect transistor Q2 connected to the battery terminal B+, the first field effect transistor Q1 and the second field effect transistor Q2 are connected in parallel, the gates of the first field effect transistor Q1 and the second field effect transistor Q2 are respectively connected to the half-bridge control unit 300, the first field effect transistor Q1 is connected to the load terminal OUT through two parallel fuses F1 and F2, and the second field effect transistor Q2 is connected to the load terminal OUT through two parallel fuses F3 and F4; the first field effect transistor Q1 or the second field effect transistor Q2 is connected to the load terminal OUT through the two parallel fuses F3 and F4; When tube Q2 loses control, the two fuses connected to the field effect tube melt to provide out-of-control circuit protection. Specifically, Q1 and Q2 are connected in parallel, and the current passing through fuses F1, F2 and F3, F4 is half of the rated current; during normal operation, Q1 and Q2 are connected, and fuses F1, F2; F3, F4 pass about half of the current respectively; if one field effect tube loses control, the current passing through the fuse doubles, and the heat of the out-of-control field effect tube is directly transferred to the fuse, and the fuse quickly melts; after the microcontroller detects that the field effect tube is out of control, it locks the relay and no longer outputs.

[0026] In the above embodiment, preferably, when the voltage of the battery terminal B+ is higher than 40V and the duration is longer than 2-20ms, the single-chip control unit controls the first field effect tube and the second field effect tube to be turned on for 500ms, so as to absorb the energy of the generator after the load dump through the grid heater. Specifically, the principle of load dump pulse absorption is that when the single-chip detects that the voltage of the battery terminal "B+" is higher than 40V and the duration is longer than 2-20mS, Q1 / Q2 is controlled to be turned on for 500mS, so as to absorb the energy of the generator after the load dump through the grid heater; 2-20mS is selected because the time of other interference pulses except the load dump is much shorter than 2mS, and the time that the electronic preheating relay can withstand in the disconnected state is longer than 10-30mS.

[0027] In the above embodiment, preferably, the first voltage stabilizing circuit 400 includes a third triode Q3 connected to the single-chip control unit 200 through a thirty-fifth resistor R35, the emitter of the third triode Q3 is connected to the thirty-fifth resistor R35, the collector of the third triode Q3 is connected to the battery terminal B+ through the twentieth resistor R20, and the base of the third triode Q3 is connected to the battery terminal B+ through the seventh resistor R7 and the thirty-fourth resistor R34; the base of the third triode Q3 is also connected to the thirty-fifth resistor R35 through the first diode D1 and the tenth capacitor C10, and the tenth capacitor C10 is also connected in parallel with the twelfth capacitor C12. Preferably, the seventh resistor R7 is connected to the battery terminal B+ through the thirty-fourth resistor R34, and the seventh resistor R7 is also grounded through the fourth voltage-dividing resistor R4 and the twenty-fourth voltage-dividing resistor R24, and a terminal RAO ​​connected to the single-chip chip U1 is provided between the fourth voltage-dividing resistor R4 and the twenty-fourth voltage-dividing resistor R24 ​​to detect the voltage of the battery terminal B+.

[0028] In the above embodiment, preferably, the second voltage stabilizing circuit 600 includes a fifth transistor Q5 connected to the half-bridge control unit 300 through a sixth diode D6, the anode of the sixth diode D6 is connected to the emitter of the fifth transistor Q5, the collector of the fifth transistor Q5 is connected to the base through a sixth resistor R6, the base of the fifth transistor Q5 is grounded through the second voltage stabilizing diode D2, and the cathode of the sixth diode D6 is grounded through the third capacitor C3.

[0029] The working principle and working process of the electronic preheating relay of the diesel engine in the above embodiment are as follows: the first input terminal IN1 is connected to the resistor R3, and then grounded through R26, the other end of R3 is connected to the pin RC1 of the single-chip chip U1, the second input terminal IN2 is connected to the resistor R2, and then grounded through R25, the other end of R2 is connected to the pin RC2 of the single-chip chip U1, the single-chip chip U1 compares the voltages of the pins RC1 and RC2, if the voltage difference is less than 0.5-6V, the pin RA5 of the single-chip chip U1 outputs a high voltage, the pin HO of the half-bridge controller U2 outputs a high voltage, the field effect tubes Q1 and Q2 are turned on, and the load terminal OUT outputs a high voltage; in the electronic preheating relay, R20, R7, R35, D1, C12, C10, Q3 form a first voltage stabilizing circuit to provide power for the single-chip chip U1; R6, D2, D6, C3, Q5 form a second voltage stabilizing circuit to provide power for the half-bridge controller U2 Provide power; R8, R10, R11, R13, R14, R17, R18, D3, D5, D8, D9, D10, C9, C11, Q4, Q6 form an oscillating boost circuit; R4, R24 are connected in series to the pin RA0 of the microcontroller chip U1 to detect the voltage of the battery terminal B+; R23, R9 are connected in series to the pin RA1 of the microcontroller chip U1 to quickly detect the voltage of the load terminal OUT; R30, R2 2 series voltage divider connected to pin RA2 of microcontroller chip U1 to detect the voltage of load terminal OUT slowly; resistors R16, R29 and thermistor R28 connected to pin RA4 of microcontroller chip U1 to detect the temperature of aluminum-based PCB board; half-bridge controller U2 provides conduction voltage for gates of field effect tubes Q1 and Q2, field effect tubes Q1, Q2 and fuses F1, F2, F3, F4 are connected in series, when Q1 or Q2 is directly connected, F1, F2, F3, F4 are disconnected. Pin RC0 of microcontroller chip U1 is connected to resistor R12, R12 is connected to light-emitting diode D11, indicating the state of electronic preheating relay. The single-chip microcomputer chip U1 calculates the voltage between pin RA0 and pin RA1, which is the voltage difference between field effect tubes Q1, Q2 and fuses F1, F2, F3, and F4. According to the characteristics of field effect tubes and fuses, the current is related to the voltage. Through temperature correction, the current passing through Q1 and Q2 can be calculated, so that overcurrent and short circuit protection can be performed; the timed shutdown is realized inside the single-chip microcomputer chip U1. Its working process is as follows: in the non-working state, the first input terminal IN1 or the second input terminal IN2 is at a high level, and the other end is suspended. The voltage difference detected by pins RC1 and RC2 of the single-chip microcomputer chip U1 is less than 0.5--6V, and pin RA5 outputs a low level.When working, the first input terminal IN1 or the second input terminal IN2 is at a high level, and the other end is at a low level. The voltage difference detected by the pins RC1 and RC2 of the single-chip microcomputer chip U1 is greater than 0.5--6V, and the pin RA3 outputs a high level. The oscillation boost circuit starts to work, and the pin RA5 outputs a high level pulse of 4--100μS. The pin HO of the half-bridge controller U2 outputs a high level, and the field effect tubes Q1 and Q2 are turned on. The pin RA0 of the single-chip microcomputer chip U1 detects the battery connection. If the voltage of terminal B+ is lower than 1--10V, it is judged that a short circuit has occurred; if the voltage is lower than 1--10V, pin RA5 outputs a high level, and field effect tubes Q1 and Q2 are turned on. Pins RA0 and RA1 detect the voltage of battery terminal B+ and load terminal OUT respectively. If the voltage difference is higher than 0.5V, pin RA5 outputs a low level, and field effect tubes Q1 and Q2 are turned off; if it is lower than 0.5V, pin RA5 outputs a high level, and field effect tubes Q1 and Q2 are turned on. During the conduction period of field effect tubes Q1 and Q2, the temperature is calculated by the resistance value of thermistor R28. When the temperature is higher than 90--110℃, pin RA5 outputs a low level, and field effect tubes Q1 and Q2 are turned off. If the above shutdown conditions do not appear, the timing starts from the output of a high level from pin RA5. When the time reaches 150S, pin RA5 outputs a low level, and field effect tubes Q1 and Q2 are turned off. The electronic preheating relay can protect against over-temperature, overload, short-circuit, and out-of-control circuit breaking. It also has timing and load dumping absorption functions. It has the advantages of large current (300A), small size, light weight, and low power consumption, which can ensure the reliable operation of the electronic preheating relay.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electronic preheating relay for a diesel engine, comprising a control box fixed on a metal plate, the control box being provided with a battery terminal, a load terminal and two input terminals, and a control circuit being provided in the control box, characterized in that: The control circuit includes a signal input unit, a single-chip control unit, a half-bridge control unit, a first voltage stabilizing circuit, a second voltage stabilizing circuit and an oscillating boost unit, wherein the signal input unit is connected to the two input terminals and the single-chip control unit, the first voltage stabilizing circuit is connected to the battery terminal and the single-chip control unit to power the single-chip control unit, and the second voltage stabilizing circuit is connected to the battery terminal and the half-bridge control unit to power the half-bridge control unit; the oscillating boost unit is connected to the battery terminal and the half-bridge control unit, and the half-bridge control unit is connected to a driving circuit, which is respectively connected to the battery terminal, the load terminal and the half-bridge control unit to control the output of the load terminal; the single-chip control unit is also connected to a thermistor for detecting the temperature of the aluminum-based PCB board; the single-chip control unit can control the output of the load terminal by collecting the input signals of the two input terminals and the temperature of the aluminum-based PCB board; The driving circuit comprises a first field effect transistor and a second field effect transistor connected to the battery terminal, the first field effect transistor and the second field effect transistor are connected in parallel; the gates of the first field effect transistor and the second field effect transistor are respectively connected to the half-bridge control unit, the first field effect transistor is connected to the load terminal through two parallel fuses, and the second field effect transistor is connected to the load terminal through two parallel fuses; when the first field effect transistor or the second field effect transistor is out of control, the two fuses connected to the field effect transistor are melted to perform out-of-control circuit protection; The single-chip microcomputer control unit includes a single-chip microcomputer chip connected to the first voltage stabilizing circuit and the signal input unit, one pin of the single-chip microcomputer chip is grounded through a sixteenth resistor, a temperature detection circuit is connected in parallel at both ends of the sixteenth resistor, and the temperature detection circuit includes a thirty-third resistor and the thermistor connected in series.

2. The electronic preheating relay according to claim 1, characterized in that: The signal input unit includes a third resistor connected to the first input terminal and a second resistor connected to the second input terminal, a first resistor is arranged between the first input terminal and the second input terminal, the third resistor and the second resistor are grounded through a twenty-sixth voltage-dividing resistor and a twenty-fifth voltage-dividing resistor respectively, a wiring terminal connected to the single-chip control unit is arranged between the third resistor and the twenty-sixth voltage-dividing resistor, and a wiring terminal connected to the single-chip control unit is arranged between the second resistor and the twenty-fifth voltage-dividing resistor.

3. The electronic preheating relay according to claim 1, characterized in that: The half-bridge control unit comprises a half-bridge controller connected to the single-chip control unit, and the half-bridge controller is respectively connected to the second voltage stabilizing circuit, the oscillation boost unit, the drive circuit, and the load terminal.

4. The electronic preheating relay according to claim 1, characterized in that: The load terminal is also connected to a voltage detection circuit, which includes a thirty-first resistor connected to the load terminal, the thirty-first resistor is grounded through a twenty-third voltage-dividing resistor and a ninth voltage-dividing resistor, a fast voltage detection terminal connected to the single-chip control unit is provided between the twenty-third voltage-dividing resistor and the ninth voltage-dividing resistor, and an eighth capacitor is also connected in parallel at both ends of the ninth voltage-dividing resistor; the thirty-first resistor is also grounded through a thirty-tenth voltage-dividing resistor and a twenty-second voltage-dividing resistor, a slow voltage detection terminal connected to the single-chip control unit is provided between the thirty-tenth voltage-dividing resistor and the twenty-second voltage-dividing resistor, and a seventh capacitor is also connected in parallel at both ends of the twenty-second voltage-dividing resistor.

5. The electronic preheating relay according to claim 1, characterized in that: The oscillation boost unit includes a fourth triode whose base is connected to the single-chip control unit through an eleventh resistor, and a sixth triode connected to the single-chip control unit through a tenth resistor. The emitter of the fourth triode is grounded, the emitter of the sixth triode is grounded, the collector of the fourth triode is connected to the battery terminal through a thirteenth resistor, and the collector of the fourth triode is also connected to the battery terminal through an eleventh capacitor, an eighth diode, and an eighteenth resistor connected in sequence; the collector of the sixth triode is connected to the battery terminal through a fourteenth resistor, and the collector of the sixth triode is also connected to the load terminal through a ninth capacitor, a tenth diode, a seventeenth resistor, and a second capacitor connected in sequence, and the load terminal is also connected to the collector of the sixth triode through a third voltage-stabilizing diode, an eighth resistor, a fifth diode, and a ninth capacitor connected in sequence, and the collector of the fourth triode is also connected to the load terminal through an eleventh capacitor, a ninth diode, and a second capacitor connected in sequence.

6. The electronic preheating relay according to claim 1, characterized in that: The first voltage stabilizing circuit includes a third transistor connected to the single-chip computer control unit through a thirty-fifth resistor, the emitter of the third transistor is connected to the thirty-fifth resistor, the collector of the third transistor is connected to the battery terminal through a twentieth resistor, and the base of the third transistor is connected to the battery terminal through a seventh resistor and a thirty-fourth resistor; the base of the third transistor is also connected to the thirty-fifth resistor through a first diode and a tenth capacitor, and the tenth capacitor is also connected in parallel with a twelfth capacitor.

7. The electronic preheating relay according to claim 6, characterized in that: The seventh resistor is connected to the battery terminal through the thirty-fourth resistor, and the seventh resistor is also grounded through the fourth voltage-dividing resistor and the twenty-fourth voltage-dividing resistor. A terminal RAO ​​connected to the microcontroller chip is provided between the fourth voltage-dividing resistor and the twenty-fourth voltage-dividing resistor to detect the voltage of the battery terminal.

8. The electronic preheating relay according to claim 1, characterized in that: The second voltage stabilizing circuit includes a fifth transistor connected to the half-bridge control unit through a sixth diode, the anode of the sixth diode is connected to the emitter of the fifth transistor, the collector of the fifth transistor is connected to the base through a sixth resistor, the base of the fifth transistor is grounded through a second voltage stabilizing diode, and the cathode of the sixth diode is grounded through a third capacitor.

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