Warning lamp circuit

Abstract

The utility model discloses a warning lamp circuit in the field of warning lamp circuit design, which comprises N input circuits, a power supply control circuit, a singlechip control circuit, a synchronous mode switching circuit and a switch LED (light-emitting diode) driving circuit, and N is a natural number not less than 2; the N input circuits are connected with the power supply control circuit, the power supply control circuit is further connected with the chip machine control circuit, the synchronous mode switching circuit and the switch LED drive circuit, and the single-chip microcomputer control circuit is further connected with the synchronous mode switching circuit and the switch LED drive circuit. The synchronous mode switching circuit comprises a synchronous signal output circuit, and the synchronous signal output circuit comprises a first MOS switch and a second MOS switch which are connected with each other. The problem that current leakage occurs when an existing warning lamp circuit starts synchronization is solved, the problem that current leakage occurs when the warning lamp circuit starts synchronization can be prevented, and therefore the phenomenon that a warning lamp flashes once when running in a low-brightness normally-on mode is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of warning light circuit design, in particular to a warning light circuit. Background Art

[0002] As modern road safety becomes increasingly important, the role of warning lights on vehicles is becoming more and more important. Given the limited number of lights that can be installed on a single vehicle (whether it is a motorcycle or a car), the purpose of the lights and the brightness they can output in a fixed unit are very important. Warning lights that are allowed to be installed as additional lights under the framework of relevant laws and regulations naturally require flexibility and functionality in practical applications.

[0003] In actual applications, in order to improve the warning effect, many vehicles will be equipped with multiple warning lights, and strive to achieve the effect of synchronous and same-frequency flashing or same-frequency asynchronous flashing, which can not only enhance the visual impact of the warning lights, but also to a certain extent increase the attention of other road users to the vehicle, thereby further reducing the risk of traffic accidents. However, the existing warning light circuit may have a current leakage problem when starting synchronization, resulting in the warning light flashing with the synchronization signal when running at low brightness, which not only affects the visual effect of the warning light, but also may mislead other road users and increase the risk of traffic accidents.

[0004] The above defects need to be solved urgently. Utility Model Content

[0005] In order to solve the problem that the existing warning light circuit has current leakage when starting synchronization, causing the warning light to flash along with the synchronization signal, the utility model provides a warning light circuit.

[0006] The technical solution of the utility model is as follows:

[0007] A warning light circuit includes an N-way input circuit, a power supply control circuit, a single-chip control circuit, a synchronous mode switching circuit, and a switch LED drive circuit, wherein N is a natural number not less than 2;

[0008] The N-way input circuit is connected to the power supply control circuit, and the power supply control circuit is also connected to the microcontroller control circuit, the synchronous mode switching circuit, and the switch LED drive circuit respectively, and the microcontroller control circuit is also connected to the synchronous mode switching circuit and the switch LED drive circuit respectively;

[0009] The synchronous mode switching circuit includes a synchronous signal output circuit, and the synchronous signal output circuit includes a first MOS switch and a second MOS switch, and the first MOS switch is connected to the second MOS switch.

[0010] According to the above scheme of the utility model, the synchronous mode switching circuit also includes a synchronous signal receiving circuit and a mode switching circuit. The synchronous signal output circuit is respectively connected to the power supply control circuit, the single-chip control circuit, and the synchronous signal receiving circuit. The synchronous signal receiving circuit is also connected to the single-chip control circuit, and the mode switching circuit is also connected to the single-chip control circuit.

[0011] According to the utility model of the above scheme, the D pole of the first MOS switch is connected to the synchronization signal receiving circuit, the G pole of the first MOS switch is respectively connected to one end of the first resistor R1 and one end of the second resistor R2, the S pole of the first MOS switch and the other end of the first resistor R1 are both connected to the power supply control circuit, the other end of the second resistor R2 is connected to the D pole of the second MOS switch, the S pole of the second MOS switch is grounded, the G pole of the second MOS switch is respectively connected to one end of the third resistor R3 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is grounded, and the other end of the third resistor R3 is connected to the single-chip computer control circuit.

[0012] According to the above solution of the utility model, the first MOS switch is an NMOS switch, and the second MOS switch is a PMOS switch.

[0013] According to the above scheme of the utility model, the synchronization signal receiving circuit includes a tenth resistor R10, a seventh capacitor C7, a third diode D3, and a ninth resistor R9, one end of the tenth resistor R10, one end of the seventh capacitor C7, one end of the third diode D3, and one end of the ninth resistor R9 are all connected to the single-chip control circuit, the other end of the tenth resistor R10, the other end of the seventh capacitor C7, and the other end of the third diode D3 are all grounded, and the other end of the ninth resistor R9 is connected to the synchronization signal output circuit.

[0014] According to the above scheme of the utility model, the mode switching circuit includes an eighth resistor R8, a sixth capacitor C6, a second diode D2, and a seventh resistor R7, one end of the eighth resistor R8, one end of the sixth capacitor C6, one end of the second diode D2, and the seventh resistor R7 are all connected to the single-chip control circuit, and the other end of the eighth resistor R8, the other end of the sixth capacitor C6, and the other end of the second diode D2 are all grounded.

[0015] According to the above scheme of the utility model, the synchronous mode switching circuit includes a synchronous signal output circuit and a signal receiving switching circuit. The synchronous signal output circuit is respectively connected to the power supply control circuit and the signal receiving switching circuit. The signal receiving switching circuit is also connected to the single-chip microcomputer control circuit.

[0016] According to the above scheme of the utility model, the power supply control circuit includes an EMI filter circuit, an overvoltage protection circuit, and a single-chip microcomputer power supply circuit. The EMI filter circuit is respectively connected to the N-way input circuit and the overvoltage protection circuit. The overvoltage protection circuit is also respectively connected to the single-chip microcomputer power supply circuit, the synchronous mode switching circuit, and the switch LED drive circuit. The single-chip microcomputer power supply circuit is also connected to the single-chip microcomputer control circuit.

[0017] According to the utility model of the above scheme, the EMI filtering circuit includes a common-mode inductor CMC, a first pin of the common-mode inductor CMC is connected to the N-way input circuit, a fourth pin of the common-mode inductor CMC is respectively connected to one end of the eighth capacitor C8 and one end of the first inductor L1, the other end of the first inductor L1 is respectively connected to one end of the ninth capacitor C9 and the overvoltage protection circuit, and the second pin of the common-mode inductor CMC, the third pin of the common-mode inductor CMC, the other end of the eighth capacitor C8, and the other end of the ninth capacitor C9 are all grounded.

[0018] According to the utility model of the above scheme, the overvoltage protection circuit includes a fifteenth resistor R15, one end of the fifteenth resistor R15 is respectively connected to the EMI filter circuit, the S pole of the second MOS tube Q2, and the E pole of the transistor Q3, the other end of the fifteenth resistor R15 is respectively connected to one end of the sixteenth resistor R16 and one end of the twelfth diode D12, the other end of the sixteenth resistor R16 is connected to the B pole of the transistor Q3, the C pole of the transistor Q3 and the G pole of the second MOS tube Q2 are both connected to one end of the seventeenth resistor R17, the other end of the seventeenth resistor R17 and the other end of the twelfth diode D12 are both grounded, and the D pole of the second MOS tube Q2 is connected to the single-chip power supply circuit.

[0019] According to the utility model of the above scheme, the single-chip microcomputer power supply circuit includes a first capacitor C1, one end of the first capacitor C1 is respectively connected to the overvoltage protection circuit and the sixth pin of the second chip U2, the first pin of the second chip U2 is connected to one end of the second capacitor C2, and the other end of the first capacitor C1, the second pin of the second chip U2, the third pin of the second chip U2, the fifth pin of the second chip U2, the seventh pin of the second chip U2, and the other end of the second capacitor C2 are all grounded.

[0020] The utility model according to the above scheme has the following beneficial effects:

[0021] In the above-mentioned warning light circuit, the synchronization signal output circuit includes a first MOS switch and a second MOS switch. The first MOS switch is connected to the second MOS switch. The first MOS switch and the second MOS switch cooperate with each other to make the warning light in a high level state when it is started, so as to avoid matching difficulties for the synchronization signal and prevent current leakage in the warning light circuit when starting synchronization, thereby avoiding the flashing phenomenon of the warning light when it is running at low brightness. The visual effect of the warning light can be improved and the risk of traffic accidents can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is one of the circuit block diagrams of the utility model;

[0023] Figure 2 This is the second circuit block diagram of the utility model;

[0024] Figure 3 This is the circuit diagram of the N-way input circuit;

[0025] Figure 4 This is the circuit diagram of the EMI filter circuit;

[0026] Figure 5 is a circuit diagram of an overvoltage protection circuit;

[0027] Figure 6 Circuit diagram of the power supply circuit for the microcontroller;

[0028] Figure 7 A circuit diagram of a synchronous signal output circuit;

[0029] Figure 8 A circuit diagram of a synchronization signal receiving circuit;

[0030] Fig. 9 is a circuit diagram of a mode switching circuit;

[0031] Fig.10 This is the circuit diagram of the microcontroller control circuit. DETAILED DESCRIPTION

[0032] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] like Figure 1 , Figure 2As shown, the utility model provides a warning light circuit, including N-way input circuit, power supply control circuit, single-chip control circuit, synchronous mode switching circuit, switch LED drive circuit, wherein N is a natural number not less than 2; the N-way input circuit is connected to the power supply control circuit, the power supply control circuit is also respectively connected to the microcontroller control circuit, the synchronous mode switching circuit, and the switch LED drive circuit, and the single-chip control circuit is also respectively connected to the synchronous mode switching circuit and the switch LED drive circuit.

[0034] like Figure 1 , Figure 3 As shown, in this embodiment, N is selected as 2, that is, the warning light circuit includes two input circuits, and the two input circuits are connected to the single-chip control circuit, so that the warning light supports two color configurations. Of course, in other embodiments, the control of warning lights of other numbers of colors can also be realized, for example, the control of warning lights of three colors, the control of warning lights of four colors, and in actual design, the number of input circuits can be designed according to actual needs, as long as the housing of the warning light can accommodate so many components and the selected single-chip supports so many color inputs.

[0035] like Figure 1 , Figure 3 As shown, in this embodiment, the input circuit includes a fourth diode D4, a fifth diode D5, a sixth diode D6, an eleventh resistor R11, a tenth capacitor C10, a seventh diode D7, and a twelfth resistor R12, wherein the fifth diode D5 is a TVS diode, which can instantly convert its own high-resistance characteristics into low-resistance characteristics, thereby effectively absorbing and suppressing the instantaneous overvoltage or surge pulse voltage that may occur in the circuit. In addition, the fourth diode D4 and the sixth diode D6 are Schottky diodes, and the sixth diode D6 is to play a role in reverse connection protection. In addition to reverse connection protection, the fourth diode D4 will also prevent the current from other roads from causing misjudgment to the branch where the sixth diode D6 is located, wherein the circuit after the fourth diode D4 is the power supply back end. In addition, the eleventh resistor R11, the tenth capacitor C10, the seventh diode D7, and the twelfth resistor R12 are combined into a Zener diode buck circuit, which is used to reduce the input voltage to a range that can be input to the single-chip computer IO, and is used to sense the power supply of the corresponding color, so that the power supply of each road will eventually be summarized at POWER_RAIL through the Schottky diode.

[0036] like Figure 2As shown, in this embodiment, the power supply control circuit includes an EMI filter circuit, an overvoltage protection circuit, and a single-chip power supply circuit. The EMI filter circuit is connected to the N-way input circuit and the overvoltage protection circuit respectively. The overvoltage protection circuit is also connected to the single-chip power supply circuit, the synchronous mode switching circuit, and the switch LED drive circuit respectively. The single-chip power supply circuit is also connected to the single-chip control circuit. Of course, in actual design, the power supply control circuit can be designed according to actual needs.

[0037] like Figure 2 , Figure 4 , Fig.10 As shown, in this embodiment, the EMI filter circuit includes a common mode inductor CMC, a first pin of the common mode inductor CMC is connected to the N-way input circuit, a fourth pin of the common mode inductor CMC is respectively connected to one end of the eighth capacitor C8 and one end of the first inductor L1, the other end of the first inductor L1 is respectively connected to one end of the ninth capacitor C9 and the overvoltage protection circuit, and the second pin of the common mode inductor CMC, the third pin of the common mode inductor CMC, the other end of the eighth capacitor C8, and the other end of the ninth capacitor C9 are all grounded. If a switch LED driver is used and there are EMC requirements, a filter circuit needs to be added to the back end of the power supply, and the back end power supply will go out from FILTERED_POWER_RAIL.

[0038] like Figure 2 , Figure 5 , Fig.10 As shown, in this embodiment, the overvoltage protection circuit includes a fifteenth resistor R15, one end of the fifteenth resistor R15 is respectively connected to the EMI filter circuit, the S pole of the second MOS tube Q2, and the E pole of the transistor Q3, the other end of the fifteenth resistor R15 is respectively connected to one end of the sixteenth resistor R16 and one end of the twelfth diode D12, the other end of the sixteenth resistor R16 is connected to the B pole of the transistor Q3, the C pole of the transistor Q3 and the G pole of the second MOS tube Q2 are both connected to one end of the seventeenth resistor R17, the other end of the seventeenth resistor R17 and the other end of the twelfth diode D12 are both grounded, and the D pole of the second MOS tube Q2 is connected to the single-chip power supply circuit. The overvoltage protection circuit can prevent the warning light from being damaged due to excessive current, can improve the overall stability of the circuit, and improve the warning effect, and reduce power waste. The utility model does not need to use multiple groups of overvoltage protection circuits to protect each circuit separately, and only uses a total overvoltage protection circuit to protect the entire single-chip control logic and the back end of the switch LED drive circuit.

[0039] like Figure 2 , Figure 6 , Fig.10As shown, in this embodiment, the single-chip microcomputer power supply circuit includes a first capacitor C1, one end of the first capacitor C1 is respectively connected to the overvoltage protection circuit and the sixth pin of the second chip U2, the first pin of the second chip U2 is connected to one end of the second capacitor C2, and the other end of the first capacitor C1, the second pin of the second chip U2, the third pin of the second chip U2, the fifth pin of the second chip U2, the seventh pin of the second chip U2, and the other end of the second capacitor C2 are all grounded.

[0040] like Figure 2 As shown, in this embodiment, the synchronous mode switching circuit also includes a synchronous signal output circuit, a synchronous signal receiving circuit, and a mode switching circuit. The synchronous signal output circuit is respectively connected to the power supply control circuit, the single-chip control circuit, and the synchronous signal receiving circuit. The synchronous signal receiving circuit is also connected to the single-chip control circuit, and the mode switching circuit is also connected to the single-chip control circuit.

[0041] like Figure 2 , Figure 7 , Fig.10 As shown, in this embodiment, the synchronization signal output circuit includes a first MOS switch Q1, the D pole of the first MOS switch Q1 is connected to the synchronization signal receiving circuit, the G pole of the first MOS switch Q1 is respectively connected to one end of the first resistor R1 and one end of the second resistor R2, the S pole of the first MOS switch Q1 and the other end of the first resistor R1 are both connected to the power supply control circuit, the other end of the second resistor R2 is connected to the D pole of the second MOS switch Q8, the S pole of the second MOS switch Q8 is grounded, the G pole of the second MOS switch Q8 is respectively connected to one end of the third resistor R3 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is grounded, and the other end of the third resistor R3 is connected to the single-chip control circuit. The synchronization signal output circuit uses fewer components and reduces the complexity of the circuit.

[0042] like Figure 2 , Figure 8 , Fig.10As shown, in this embodiment, the first MOS switch Q1 is an NMOS switch, and the second MOS switch Q8 is a PMOS switch. When the NMOS switch is not turned on by SYNC_OUT, it is in a closed state. At this time, the current passes from the third resistor R3 to the G pole of the PMOS switch, so that the PMOS switch is in a closed state, and then SYNC_SIGNAL will not have any output. When the NMOS switch is turned on, the current flows to the ground through the NMOS switch to lower the voltage of the entire line. The first resistor R1 is to control the current so that it will not be too large to damage the NMOS switch. When the line is grounded to 0V, the PMOS switch will be turned on, and the current will be output through SYNC_SIGNAL. Compared with the existing method of only setting an NMOS switch, the utility model can output a signal without the signal voltage being received by the synchronization signal, and the third resistor R3 of the circuit forms a voltage divider resistor circuit to lower the voltage. In addition, since the NMOS switch cannot control the high level of the output signal when it is not turned on, and the microcontroller has not completed the initialization to control the signal, the warning light will be in a high level state for the first 40ms before it is started. The utility model cooperates with the first MOS switch Q1 and the second MOS switch Q8 to make the warning light in a high level state when it is started, thereby avoiding matching difficulties for the synchronization signal and preventing current leakage in the warning light circuit when starting the synchronization, thereby avoiding the flashing phenomenon of the warning light when it is running at low brightness, which can improve the visual effect of the warning light and reduce the risk of traffic accidents.

[0043] like Figure 2 , Fig. 9 , Fig.10 As shown, in this embodiment, the synchronization signal receiving circuit includes a tenth resistor R10, a seventh capacitor C7, a third diode D3, and a ninth resistor R9, one end of the tenth resistor R10, one end of the seventh capacitor C7, one end of the third diode D3, and one end of the ninth resistor R9 are all connected to the single-chip control circuit, the other end of the tenth resistor R10, the other end of the seventh capacitor C7, and the other end of the third diode D3 are all grounded, and the other end of the ninth resistor R9 is connected to the synchronization signal output circuit. The ninth resistor R9, the third diode D3, the seventh capacitor C7, and the tenth resistor R10 are combined into a Zener diode buck circuit.

[0044] In this embodiment, the mode switching circuit includes an eighth resistor R8, a sixth capacitor C6, a second diode D2, and a seventh resistor R7. One end of the eighth resistor R8, one end of the sixth capacitor C6, one end of the second diode D2, and the seventh resistor R7 are all connected to the single-chip control circuit, and the other end of the eighth resistor R8, the other end of the sixth capacitor C6, and the other end of the second diode D2 are all grounded.

[0045] In an optional embodiment, the synchronous mode switching circuit includes a synchronous signal output circuit and a signal receiving switching circuit. The synchronous signal output circuit is respectively connected to the power supply control circuit and the signal receiving switching circuit. The signal receiving switching circuit is also connected to the single-chip microcomputer control circuit to realize the integration of synchronous signal reception and mode switching. The single-chip microcomputer determines whether to enter the flashing mode switching mode through the PAT_SWT_DET pin.

[0046] In an optional embodiment, the traditional warning light driving two-color lamp beads requires four sets of linear power supply principle LED driving circuits to drive, which occupies a large space on the circuit board. The switch LED driving circuit of this embodiment includes an LED driving chip, which controls the switch of the LED chip through the EN pin, and controls all lamp beads through one LED driving chip. Under the same configuration of driving two-color lamp beads, the switch LED driving circuit of this embodiment only needs to use two sets. Compared with the traditional linear LED driving circuit, the switch LED driving circuit of this embodiment leaves more space on the same unit area of ​​the circuit board, greatly improving the high heating problem caused by the previous linear LED drive, so that it can also maintain 30% lower heating in a 12V power supply environment, and 50% lower in a 24V environment. At the same time, it also supports PWM and voltage dimming functions, so that the LED driver outputs more power and makes the lamp beads brighter than before. In addition, in order to improve the EMI problem caused by the switch LED driving circuit, the extra space can choose to add a set of EMI filter circuits to make it meet the standards for vehicle-grade police lights. Of course, in actual design, the LED driving circuit can be designed according to actual needs.

[0047] In an optional embodiment, by placing an NMOS switch under the LED lamp bead string, the microcontroller can independently drive multiple groups of parallel lamp bead strings under a single LED driver chip, and by adjusting the parameters of the overvoltage protection circuit, it can adapt to higher voltage input.

[0048] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the claims attached to the utility model.

[0049] The above is an exemplary description of the utility model patent in conjunction with the accompanying drawings. It is obvious that the implementation of the utility model patent is not limited to the above-mentioned method. As long as various improvements are made by adopting the method concept and technical solution of the utility model patent, or the concept and technical solution of the utility model patent are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.

Claims

1. A warning light circuit, characterized in that: It includes N-way input circuit, power supply control circuit, single chip control circuit, synchronous mode switching circuit, switch LED driving circuit, wherein N is a natural number not less than 2; The N-way input circuit is connected to the power supply control circuit, and the power supply control circuit is also connected to the microcontroller control circuit, the synchronous mode switching circuit, and the switch LED drive circuit respectively, and the microcontroller control circuit is also connected to the synchronous mode switching circuit and the switch LED drive circuit respectively; The synchronous mode switching circuit includes a synchronous signal output circuit, and the synchronous signal output circuit includes a first MOS switch and a second MOS switch, and the first MOS switch is connected to the second MOS switch.

2. The warning light circuit according to claim 1, characterized in that: The synchronous mode switching circuit also includes a synchronous signal receiving circuit and a mode switching circuit. The synchronous signal output circuit is respectively connected to the power supply control circuit, the single-chip control circuit, and the synchronous signal receiving circuit. The synchronous signal receiving circuit is also connected to the single-chip control circuit. The mode switching circuit is also connected to the single-chip control circuit.

3. The warning light circuit according to claim 2, characterized in that: The D pole of the first MOS switch is connected to the synchronization signal receiving circuit, the G pole of the first MOS switch is respectively connected to one end of the first resistor R1 and one end of the second resistor R2, the S pole of the first MOS switch and the other end of the first resistor R1 are both connected to the power supply control circuit, the other end of the second resistor R2 is connected to the D pole of the second MOS switch, the S pole of the second MOS switch is grounded, the G pole of the second MOS switch is respectively connected to one end of the third resistor R3 and one end of the sixth resistor R6, the other end of the sixth resistor R6 is grounded, and the other end of the third resistor R3 is connected to the single-chip computer control circuit.

4. The warning light circuit according to claim 2, characterized in that: The first MOS switch is an NMOS switch, and the second MOS switch is a PMOS switch.

5. The warning light circuit according to claim 2, characterized in that: The synchronization signal receiving circuit includes a tenth resistor R10, a seventh capacitor C7, a third diode D3, and a ninth resistor R9. One end of the tenth resistor R10, one end of the seventh capacitor C7, one end of the third diode D3, and one end of the ninth resistor R9 are all connected to the single-chip control circuit, the other end of the tenth resistor R10, the other end of the seventh capacitor C7, and the other end of the third diode D3 are all grounded, and the other end of the ninth resistor R9 is connected to the synchronization signal output circuit.

6. The warning light circuit according to claim 2, characterized in that: The mode switching circuit includes an eighth resistor R8, a sixth capacitor C6, a second diode D2, and a seventh resistor R7. One end of the eighth resistor R8, one end of the sixth capacitor C6, one end of the second diode D2, and the seventh resistor R7 are all connected to the single-chip control circuit, and the other end of the eighth resistor R8, the other end of the sixth capacitor C6, and the other end of the second diode D2 are all grounded.

7. The warning light circuit according to claim 1, characterized in that: The power supply control circuit includes an EMI filter circuit, an overvoltage protection circuit, and a single-chip microcomputer power supply circuit. The EMI filter circuit is respectively connected to the N-way input circuit and the overvoltage protection circuit. The overvoltage protection circuit is also respectively connected to the single-chip microcomputer power supply circuit, the synchronous mode switching circuit, and the switch LED drive circuit. The single-chip microcomputer power supply circuit is also connected to the single-chip microcomputer control circuit.

8. The warning light circuit according to claim 7, characterized in that: The EMI filtering circuit includes a common-mode inductor CMC, a first pin of the common-mode inductor CMC is connected to the N-channel input circuit, a fourth pin of the common-mode inductor CMC is respectively connected to one end of the eighth capacitor C8 and one end of the first inductor L1, the other end of the first inductor L1 is respectively connected to one end of the ninth capacitor C9 and the overvoltage protection circuit, and a second pin of the common-mode inductor CMC, a third pin of the common-mode inductor CMC, the other end of the eighth capacitor C8, and the other end of the ninth capacitor C9 are all grounded.

9. The warning light circuit according to claim 7, characterized in that: The overvoltage protection circuit includes a fifteenth resistor R15, one end of the fifteenth resistor R15 is respectively connected to the EMI filter circuit, the S pole of the second MOS tube Q2, and the E pole of the transistor Q3, the other end of the fifteenth resistor R15 is respectively connected to one end of a sixteenth resistor R16 and one end of a twelfth diode D12, the other end of the sixteenth resistor R16 is connected to the B pole of the transistor Q3, the C pole of the transistor Q3 and the G pole of the second MOS tube Q2 are both connected to one end of a seventeenth resistor R17, the other end of the seventeenth resistor R17 and the other end of the twelfth diode D12 are both grounded, and the D pole of the second MOS tube Q2 is connected to the single-chip power supply circuit.

10. The warning light circuit according to claim 7, characterized in that: The single-chip microcomputer power supply circuit includes a first capacitor C1, one end of the first capacitor C1 is respectively connected to the overvoltage protection circuit and the sixth pin of the second chip U2, the first pin of the second chip U2 is connected to one end of the second capacitor C2, the other end of the first capacitor C1, the second pin of the second chip U2, the third pin of the second chip U2, the fifth pin of the second chip U2, the seventh pin of the second chip U2, and the other end of the second capacitor C2 are all grounded.

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