Time division multiplexing control circuit compatible with single lithium battery and AA battery and used for mobile lighting equipment

Abstract

The utility model relates to the technical field of power supply control of mobile lighting equipment, in particular to a time division multiplexing control circuit compatible with a single lithium battery and an AA battery for mobile lighting equipment, which comprises a head drive board circuit and a tail board circuit. The head drive board circuit comprises a buck-boost constant current drive sub-circuit, a single-chip microcomputer power supply sub-circuit, a gear shifting signal receiving sub-circuit and a head MCU control sub-circuit. The tail board circuit comprises a tail board time division multiplexing sub-circuit, a tail board AA battery boosting power supply sub-circuit and a tail board MCU control sub-circuit, the power supply of the head driving circuit board and the power supply of the tail key circuit board are realized through the time division multiplexing control of the metal cylinder body, and meanwhile, the signals of the tail board can be effectively transmitted to the head circuit; the gear switching function of the tail light touch key is realized; and a single AA battery and a lithium battery can be compatible, so that the cost is saved, and the battery compatibility is improved.

Description

Technical Field

[0001] This utility model relates to the field of power control technology for mobile lighting equipment, and in particular to a time-division multiplexing control circuit for mobile lighting equipment compatible with single-cell lithium batteries and AA batteries. Background Technology

[0002] Common mobile lighting devices controlled by tail buttons, such as Figure 1 As shown, the metal body is connected to the positive terminal of the battery, which supplies power to the head drive circuit. The button signal line connects the head drive board and the tail button board. When the tail button is pressed, the red wire is connected to the positive terminal of the battery. The head drive board detects that the red signal line is pulled high, thereby controlling the switching on and off of the light source or adjusting its brightness. Embedding a signal wire inside the cylindrical metal body is difficult to achieve. The usual practice is to make an inner sleeve inside the metal body to transmit the button signal, which increases costs and requires a larger diameter metal body. Therefore, we propose a time-division multiplexing control circuit for mobile lighting devices that is compatible with single-cell lithium batteries and AA batteries. Utility Model Content

[0003] The main purpose of this utility model is to provide a time-division multiplexing control circuit for mobile lighting equipment that is compatible with single-cell lithium batteries and AA batteries, including a head drive board circuit and a tail board circuit.

[0004] The head drive board circuit includes a step-up / step-down constant current drive sub-circuit, a microcontroller power supply circuit, a shift signal receiving sub-circuit, and a head MCU control sub-circuit.

[0005] The tailboard circuit includes a tailboard time-division multiplexing sub-circuit, a tailboard AA battery boost power supply circuit, and a tailboard MCU control sub-circuit.

[0006] Preferably, the buck constant current driver sub-circuit includes a boost converter chip U3, an operational amplifier U4, a MOSFET Q3, a power LED D8, an inductor L3, resistors R13 to R30, and capacitors C11 to C17. Inductor L3 is connected to pins 6 and 8 of the boost converter chip U3; resistors R16 and R17 are connected to pin 5 of the boost converter chip U3; pins 9 and 1 of the boost converter chip U3 are grounded; resistor R14 and capacitor C13 are connected in parallel and then in series with resistor R15, and connected to pin 8 of the boost converter chip U3; one end of capacitors C11 and C12, and one end of resistor R13 are all connected to pin 8 of the boost converter chip U3, and the other end is grounded; pin 4 of the operational amplifier U4 is connected to pin 2 of the boost converter chip U3; one end of the MOSFET Q3 and resistor R26 are connected in parallel and then in series with resistors R20 and R22 respectively. One end of the capacitor is connected to pin 2 of the boost converter U3, and the other end is connected in parallel with capacitor C14 and then connected to pin 4 of the boost converter U3. The other end of capacitor C14 is grounded. One end of capacitor C15 is connected to pin 5 of operational amplifier U4, and the other end is grounded. Resistors R24 and R30 are connected in series, with one end grounded and the other end connected to pin 1 of operational amplifier U4. Resistors R18 and R19 are connected in series, with one end connected to pin 4 of boost converter U3 and the other end connected to pin 2 of operational amplifier U4. Resistors R23, capacitors C16 and C17, and resistor R28 are connected in parallel and then connected to the series circuit of resistors R25, R27, and R29 and then connected to pin 3 of operational amplifier U4.

[0007] Preferably, the microcontroller power supply circuit includes a linear buck converter U5, a diode D6, and capacitors C18, C19, and C20. After capacitors C18, C19, and C20 are connected in parallel, their two ends are respectively connected to pins 2 and 3 of the linear buck converter U5. Pin 1 of the linear buck converter U5 is grounded, and diode D6 is connected to pin 3 of the linear buck converter U5. Operational amplifier U4 connects the amplified signal to the linear buck converter U5.

[0008] Preferably, the shift signal receiving sub-circuit includes transistors Q4 and Q5, diode D7, resistors R33 to R37, and capacitor C23. Resistor R34, diode D7, and capacitor C23 are connected to pin 1 of transistor Q4, and the other ends of resistor R34 and capacitor C23 are grounded. Resistor R35 is connected to pin 6 of transistor Q4, and the other end is grounded. Resistor R36 is connected to pin 3 of transistor Q4. Pin 1 of transistor Q5 is connected to pin 3 of transistor Q4, and resistor R37 is connected between them. Resistor R33 is connected to pin 3 of transistor Q5, pin 2 of transistor Q5 is grounded, and linear buck converter U5 is connected to transistor Q5.

[0009] Preferably, the head MCU control sub-circuit includes a microcontroller U6, a resistor R31, and capacitors C21, C22, and C24. The resistor R31 and capacitor C21 are connected in series and then in parallel with capacitors C22 and C24, and are respectively connected to pins 5 and 6 of the microcontroller U6. Transistor Q5 is connected to the microcontroller U6, the microcontroller U6 is connected to the operational amplifier U4, and the microcontroller U6 is connected to the boost converter chip U3.

[0010] Preferably, the tailboard time-division multiplexing sub-circuit includes inductor L2, diodes D1, D2, D3, Zener diode D4, MOSFET Q1, linear regulator chip U1, resistors R1, R2, R3, and capacitors C1, C2, and C3. Diode D2 is connected to pin 2 of linear regulator chip U1. Resistor R2 and capacitor C3 are connected in parallel and then in series with resistor R1, and are connected to the series circuit of inductor L2 and diode D1. Diode D3, resistor R3, MOSFET Q1, Zener diode D4, and capacitor C1 are connected in parallel and also connected to the series circuit of inductor L2 and diode D1, and finally connected between pins 3 and 1 of linear regulator chip U1.

[0011] Preferably, the boost circuit for the AA battery at the tail plate includes a boost chip U2, a transistor Q2, a diode D5, an inductor L2, resistors R10, R11, and R12, and capacitors C7, C8, C9, and C10. Resistors R11 and R12 are connected in series and in parallel with capacitor C10 and connected to pin 3 of the boost chip U2. Pin 2 of the boost chip U2 is connected between resistors R11 and R12. Capacitor C9 and resistor R10 are connected in parallel and connected between transistor Q2 and boost chip U2. Resistor R7 is connected to pins 1 and 2 of transistor Q2. Resistor R6 is connected to pin 1 of transistor Q2. Capacitor C8 and diode D5 are connected in series and connected to pin 4 of boost chip U2. Capacitor C7 and inductor L2 are connected in series and connected to pins 5 and 4 of boost chip U2, respectively. MOSFET Q1 is connected to boost chip U2.

[0012] Preferably, the tailboard MCU control sub-circuit includes a microcontroller U7, a diode D9, buttons S1 and S2, a resistor R4, and capacitors C4, C5, and C6. Resistor R4 and capacitor C4 are connected in series and then in parallel with capacitors C5 and C6, and are respectively connected to pins 5 and 6 of microcontroller U7. Button S1 is connected to pin 10 of microcontroller U7. Button S2 and diode D9 are connected in series and then connected to pin 11 of microcontroller U7. The other ends of buttons S1 and S2 are grounded. MOSFET Q1 is connected to microcontroller U7.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] This invention achieves power supply to the head drive circuit board and the tail button circuit board through time-division multiplexing control of the metal cylinder body. At the same time, the signal from the tail plate can also be effectively transmitted to the head circuit to realize the gear switching function of the tail light touch button. It is also compatible with single AA batteries and lithium batteries, saving costs and increasing battery compatibility. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the step-up / step-down constant current drive sub-circuit of this utility model;

[0016] Figure 2 This utility model provides a microcontroller-based electronic circuit.

[0017] Figure 3 This is the shift signal receiving sub-circuit of this utility model;

[0018] Figure 4 This invention relates to the head MCU control sub-circuit.

[0019] Figure 5 This utility model relates to a time-division multiplexing sub-circuit for the tailboard.

[0020] Figure 6 This utility model provides an electronic circuit for boosting the voltage of an AA battery in the tail section.

[0021] Figure 7 This utility model relates to the MCU control sub-circuit of the tailboard. Detailed Implementation

[0022] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0023] Please see Figure 1-7 This embodiment provides a time-division multiplexing control circuit for mobile lighting devices that is compatible with single-cell lithium batteries and AA batteries, including a head drive board circuit and a tail board circuit;

[0024] The head drive board circuit includes a step-up / step-down constant current drive sub-circuit, a microcontroller power supply circuit, a shift signal receiving sub-circuit, and a head MCU control sub-circuit.

[0025] The tailboard circuit includes a tailboard time-division multiplexing sub-circuit, a tailboard AA battery boost power supply circuit, and a tailboard MCU control sub-circuit.

[0026] Preferably, the buck constant current driver sub-circuit includes a boost converter chip U3, an operational amplifier U4, a MOSFET Q3, a power LED D8, an inductor L3, resistors R13 to R30, and capacitors C11 to C17. Inductor L3 is connected to pins 6 and 8 of the boost converter chip U3; resistors R16 and R17 are connected to pin 5 of the boost converter chip U3; pins 9 and 1 of the boost converter chip U3 are grounded; resistor R14 and capacitor C13 are connected in parallel and then in series with resistor R15, and connected to pin 8 of the boost converter chip U3; one end of capacitors C11 and C12, and one end of resistor R13 are all connected to pin 8 of the boost converter chip U3, and the other end is grounded; pin 4 of the operational amplifier U4 is connected to pin 2 of the boost converter chip U3; one end of the MOSFET Q3 and resistor R26 are connected in parallel and then in series with resistors R20 and R22 respectively. One end of the capacitor is connected to pin 2 of the boost converter U3, and the other end is connected in parallel with capacitor C14 and then connected to pin 4 of the boost converter U3. The other end of capacitor C14 is grounded. One end of capacitor C15 is connected to pin 5 of operational amplifier U4, and the other end is grounded. Resistors R24 and R30 are connected in series, with one end grounded and the other end connected to pin 1 of operational amplifier U4. Resistors R18 and R19 are connected in series, with one end connected to pin 4 of boost converter U3 and the other end connected to pin 2 of operational amplifier U4. Resistors R23, capacitors C16 and C17, and resistor R28 are connected in parallel and then connected to the series circuit of resistors R25, R27, and R29 and then connected to pin 3 of operational amplifier U4.

[0027] Preferably, the microcontroller power supply circuit includes a linear buck converter U5, a diode D6, and capacitors C18, C19, and C20. After capacitors C18, C19, and C20 are connected in parallel, their two ends are respectively connected to pins 2 and 3 of the linear buck converter U5. Pin 1 of the linear buck converter U5 is grounded, and diode D6 is connected to pin 3 of the linear buck converter U5. Operational amplifier U4 connects the amplified signal to the linear buck converter U5.

[0028] Preferably, the shift signal receiving sub-circuit includes transistors Q4 and Q5, diode D7, resistors R33 to R37, and capacitor C23. Resistor R34, diode D7, and capacitor C23 are connected to pin 1 of transistor Q4, and the other ends of resistor R34 and capacitor C23 are grounded. Resistor R35 is connected to pin 6 of transistor Q4, and the other end is grounded. Resistor R36 is connected to pin 3 of transistor Q4. Pin 1 of transistor Q5 is connected to pin 3 of transistor Q4, and resistor R37 is connected between them. Resistor R33 is connected to pin 3 of transistor Q5, pin 2 of transistor Q5 is grounded, and linear buck converter U5 is connected to transistor Q5.

[0029] Preferably, the head MCU control sub-circuit includes a microcontroller U6, a resistor R31, and capacitors C21, C22, and C24. The resistor R31 and capacitor C21 are connected in series and then in parallel with capacitors C22 and C24, and are respectively connected to pins 5 and 6 of the microcontroller U6. Transistor Q5 is connected to the microcontroller U6, the microcontroller U6 is connected to the operational amplifier U4, and the microcontroller U6 is connected to the boost converter chip U3.

[0030] Preferably, the tailboard time-division multiplexing sub-circuit includes inductor L2, diodes D1, D2, D3, Zener diode D4, MOSFET Q1, linear regulator chip U1, resistors R1, R2, R3, and capacitors C1, C2, and C3. Diode D2 is connected to pin 2 of linear regulator chip U1. Resistor R2 and capacitor C3 are connected in parallel and then in series with resistor R1, and are connected to the series circuit of inductor L2 and diode D1. Diode D3, resistor R3, MOSFET Q1, Zener diode D4, and capacitor C1 are connected in parallel and also connected to the series circuit of inductor L2 and diode D1, and finally connected between pins 3 and 1 of linear regulator chip U1.

[0031] Preferably, the boost circuit for the AA battery at the tail plate includes a boost chip U2, a transistor Q2, a diode D5, an inductor L2, resistors R10, R11, and R12, and capacitors C7, C8, C9, and C10. Resistors R11 and R12 are connected in series and in parallel with capacitor C10 and connected to pin 3 of the boost chip U2. Pin 2 of the boost chip U2 is connected between resistors R11 and R12. Capacitor C9 and resistor R10 are connected in parallel and connected between transistor Q2 and boost chip U2. Resistor R7 is connected to pins 1 and 2 of transistor Q2. Resistor R6 is connected to pin 1 of transistor Q2. Capacitor C8 and diode D5 are connected in series and connected to pin 4 of boost chip U2. Capacitor C7 and inductor L2 are connected in series and connected to pins 5 and 4 of boost chip U2, respectively. MOSFET Q1 is connected to boost chip U2.

[0032] Preferably, the tailboard MCU control sub-circuit includes a microcontroller U7, a diode D9, buttons S1 and S2, a resistor R4, and capacitors C4, C5, and C6. Resistor R4 and capacitor C4 are connected in series and then in parallel with capacitors C5 and C6, and are respectively connected to pins 5 and 6 of microcontroller U7. Button S1 is connected to pin 10 of microcontroller U7. Button S2 and diode D9 are connected in series and then connected to pin 11 of microcontroller U7. The other ends of buttons S1 and S2 are grounded. MOSFET Q1 is connected to microcontroller U7.

[0033] The positive terminal of the battery is connected to the BAT+ network of the tailplate, and the negative terminal is connected to the GND network of the head drive board. The metal body connects the AGND network of the tailplate and the VDD network of the head drive board. When the battery is inserted, the battery current flows into the tailplate from the BAT+ network, through the AGND network, through the metal body, to the VDD network of the head drive circuit, and then through the R131k resistor from the GND network to the negative terminal of the battery, forming a power supply circuit for the tailplate. The microcontroller U7 has a low power consumption of 1mA. Because its power supply circuit is connected in series with R131k, excessive current will cause the voltage of the microcontroller U7 to drop below its minimum operating voltage of 1.8V. The tailplate buttons S1 and S2 are a two-stage button. Pressing the button first activates S2 for a light press, and continuing to press the button increases the travel distance, activating both S1 and S2 for a hard press.

[0034] Tailboard Time-Division Multiplexing Sub-Circuit: When MOSFET Q1 is turned on, BAT+ supplies power to the head drive circuit through inductor L1. Simultaneously, inductor L1 stores energy. When MOSFET Q1 is turned off, inductor L1 generates an induced electromotive force (EMF). Pin 1 is negative, and pin 2 is positive. The positive terminal supplies power to microcontroller U7 via diode D1 and linear buck converter U1, then flows back to the negative terminal of inductor L1 through the AGND network and diode D3. Zener diode D4 is a 10V Zener diode, protecting linear buck converter U1 when the reverse EMF voltage of L1 is too high. Capacitors C1 and C2 are filter capacitors, stabilizing the power supply voltage of microcontroller U7. R1, R2, and C3 form a series voltage divider circuit used by the microcontroller's P35 port to detect the voltage when the battery is inserted.

[0035] Tailboard AA battery booster circuit: The voltage of the AA battery is lower than the operating voltage of the microcontroller U7. This circuit boosts the voltage of the AA battery to 2.4V to power the microcontroller U7. U2 is a boost chip with a minimum operating voltage of 0.85V. The enable pin EN of U2 is connected to transistor Q2. When the button is pressed lightly, the KEY network is pulled low, and transistor Q2 conducts to start the U2 boost.

[0036] Tailboard MCU control sub-circuit: Microcontroller U7 determines the button status, detects the lithium battery voltage, and outputs PWM to control the time-division multiplexing circuit to balance the power supply between the tailboard and the headboard, as well as to transmit the shift signal; the function of diode D9 is to prevent current from flowing into microcontroller U7 when the BAT+ network voltage is higher than the VCC microcontroller power supply network voltage.

[0037] The buck-boost constant current drive sub-circuit: The positive input terminal of operational amplifier U4 samples the current of LED D8 through resistor R30, compares and amplifies it with the voltage at the inverting input terminal, and feeds it back to the FB pin of boost chip U3 through its output terminal, forming a negative feedback constant current control. When VDD is lower than LED+ voltage, boost chip U3 is in boost mode and MOSFET Q3 is in shoot-through mode, forming boost constant current; when VDD is higher than LED+ voltage, boost chip U3 is in shoot-through mode and MOSFET Q3 is in the linear region, forming buck constant current. The current magnitude is controlled by the duty cycle of PWM2. When PWM2 is high impedance, it is controlled by the voltage division of resistors R29 and R28.

[0038] The microcontroller power supply circuit uses a linear step-down 2.5V converter to power microcontroller U6. The input is connected to the vout network of boost chip U3. When using an AA battery at 1.1V, the power supply voltage of VDD2 can be kept stable at 2.5V.

[0039] Shift signal receiving sub-circuit: When low brightness is activated, the LED+ voltage is 2.6V, transistor Q4-2 in Q4 conducts. Due to the voltage drop of diode D7, transistor Q4-1 in Q4 is cut off. Therefore, pin 3 of Q4 is high, driving transistor Q5 to conduct, and the DT1 network is pulled low. When the tailboard microcontroller U7 determines through the button that it needs to switch from low brightness to high brightness, it controls MOSFET Q1 to turn off for 10ms. The input power supply VDD of the buck-boost constant current drive circuit is also cut off for 10ms. Due to the presence of R34... With a 2K resistor, the voltage across LED+ drops rapidly, while the voltage across capacitor C23 drops more slowly than that across LED+. When the voltage across LED+ is lower than the voltage across capacitor C23, transistor Q4-1 in Q4 turns on, while transistor Q4-2 turns off. Therefore, pin 3 of Q4 is at a low level, transistor Q5 is off, and the DT1 network is pulled up to a high level by resistor R33. The microcontroller U6 determines that this signal has entered the high brightness mode.

[0040] Head MCU control sub-circuit: The U6 microcontroller determines the need to switch from low brightness to high brightness via port P34, adjusts the PWM on port P15 to increase the duty cycle, and enables the buck-boost constant current drive circuit to reach the high brightness level current; the U6 microcontroller can detect the voltage of the VDD network via port P35, and when the voltage decreases, it can control the PWM duty cycle to reduce the current of LED D8.

[0041] In general, when the tailgate is pressed lightly, the microcontroller U7 determines that port P24 is low and outputs PWM through port P15. The PWM frequency is 100kHz and the duty cycle is 10%, driving MOSFET Q1. When MOSFET Q1 is on, pin 2 of inductor L1 is connected to the AGND network, which powers the head drive board via the metal body. This activates the buck-boost constant current drive circuit, with the current determined by the voltage divider between resistors R29 and R28, resulting in a low-brightness setting. When the tailgate is pressed hard, the microcontroller U7 determines that port P23 is low and controls Q1 through port P15. After the MOSFET is turned off for 10ms, the PWM duty cycle is increased to 90%. At the same time, the head shift signal receiving circuit receives the shift signal. The U6 microcontroller determines through the P34 port that it needs to switch from the low brightness level to the high brightness level, and adjusts the PWM duty cycle of the P15 port to 45% to increase the drive current of the buck-boost constant current drive circuit. When in the low brightness level or the high brightness level, pressing the button again triggers a light press or a hard press. The microcontroller U7 controls the MOSFET Q1 to turn off, VDD has no power supply, and LED D8 turns off.

[0042] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A time-multiplexed control circuit for mobile lighting device compatible single lithium and AA batteries, characterized by, The head driving plate circuit and the tail plate circuit are included; The head driving plate circuit includes a step-up constant current driving sub-circuit, a single-chip microcomputer power supply sub-circuit, a gear shifting signal receiving sub-circuit and a head MCU control sub-circuit; The tail plate circuit includes a tail plate time division multiplexing sub-circuit, a tail plate AA battery step-up power supply sub-circuit and a tail plate MCU control sub-circuit; The step-up constant current driving sub-circuit includes a step-up chip U3, an operational amplifier U4, a MOS tube Q3, a power LED D8, an inductor L3, resistors R13 to R30 and capacitors C11 to C17; the inductor L3 is connected to the 6th pin and the 8th pin of the step-up chip U3, the resistors R16 and R17 are connected to the 5th pin of the step-up chip U3, the 9th pin and the 1st pin of the step-up chip U3 are grounded, the resistor R14 and the capacitor C13 are connected in parallel and then connected in series with the resistor R15 and connected to the 8th pin of the step-up chip U3, the capacitor C11, the capacitor C12 and one end of the resistor R13 are all connected to the 8th pin of the step-up chip U3 and the other ends are grounded, the 4th pin of the operational amplifier U4 is connected to the 2nd pin of the step-up chip U3, the MOS tube Q3 and the resistor R26 are connected in parallel and then one end of the MOS tube Q3 and the resistor R20 are connected in series and one end of the MOS tube Q3 and the resistor R22 are connected in series and connected to the 2nd pin of the step-up chip U3, the other end of the MOS tube Q3 and the resistor R26 is connected in parallel with the capacitor C14 and connected to the 4th pin of the step-up chip U3, the other end of the capacitor C14 is grounded, one end of the capacitor C15 is connected to the 5th pin of the operational amplifier U4 and the other end is grounded, the resistor R24 and the resistor R30 are connected in series and one end is grounded and the other end is connected to the 1st pin of the operational amplifier U4, the resistor R18 and the resistor R19 are connected in series and one end is connected to the 4th pin of the step-up chip U3 and the other end is connected to the 2nd pin of the operational amplifier U4, the resistor R23, the capacitor C16, the capacitor C17 and the resistor R28 are connected in parallel and then connected to the resistor R25, the resistor R27 and the resistor R29 which are connected in series and connected to the 3rd pin of the operational amplifier U4; The single-chip microcomputer power supply sub-circuit includes a linear step-down chip U5, a diode D6 and capacitors C18, C19 and C20; the capacitors C18, C19 and C20 are connected in parallel and then connected to the 2nd pin and the 3rd pin of the linear step-down chip U5, the 1st pin of the linear step-down chip U5 is grounded, the diode D6 is connected to the 3rd pin of the linear step-down chip U5, and the operational amplifier U4 is connected to the linear step-down chip U5; The gear shifting signal receiving sub-circuit includes triodes Q4 and Q5, a diode D7, resistors R33 to R37 and a capacitor C23; the resistor R34, the diode D7 and the capacitor C23 are connected to the 1st pin of the triode Q4, the other end of the resistor R34 and the capacitor C23 is grounded, the resistor R35 is connected to the 6th pin of the triode Q4 and the other end is grounded, the resistor R36 is connected to the 3rd pin of the triode Q4, the 1st pin of the triode Q5 is connected to the 3rd pin of the triode Q4 and the resistor R37 is connected between the 1st pin of the triode Q5 and the 3rd pin of the triode Q4, the resistor R33 is connected to the 3rd pin of the triode Q5, the 2nd pin of the triode Q5 is grounded, and the linear step-down chip U5 is connected to the triode Q5. The head MCU control sub-circuit comprises a single-chip microcomputer U6, a resistor R31, capacitors C21, C22 and C24, the resistor R31 and the capacitor C21 are connected in series and are connected in parallel with the capacitors C22 and C24 and are connected to the pins 5 and 6 of the single-chip microcomputer U6 respectively, a triode Q5 is connected to the single-chip microcomputer U6, the single-chip microcomputer U6 is connected to an operational amplifier U4, and the single-chip microcomputer U6 is connected to a boost chip U3. The tail plate time division multiplexing sub-circuit comprises an inductor L2, diodes D1, D2 and D3, a voltage stabilizing tube D4, a MOS tube Q1, a linear voltage stabilizing chip U1, resistors R1, R2 and R3, and capacitors C1, C2 and C3, the diode D2 is connected to the pin 2 of the linear voltage stabilizing chip U1, the resistor R2 and the capacitor C3 are connected in parallel and are connected in series with the resistor R1 and are connected to the series loop of the inductor L2 and the diode D1, the diode D3, the resistor R3, the MOS tube Q1, the voltage stabilizing tube D4 and the capacitor C1 are connected in parallel and are also connected to the series loop of the inductor L2 and the diode D1, and are finally connected between the pins 3 and 1 of the linear voltage stabilizing chip U1. The tail plate AA battery boost power supply sub-circuit comprises a boost chip U2, a triode Q2, a diode D5, an inductor L2, resistors R10, R11 and R12, and capacitors C7, C8, C9 and C10, the resistors R11 and R12 are connected in series and are connected in parallel with the capacitor C10 and are connected to the pin 3 of the boost chip U2, the pin 2 of the boost chip U2 is connected between the resistors R11 and R12, the capacitor C9 and the resistor R10 are connected in parallel and are connected between the triode Q2 and the boost chip U2, the resistor R7 is connected to the pins 1 and 2 of the triode Q2, the resistor R6 is connected to the pin 1 of the triode Q2, the capacitor C8 and the diode D5 are connected in series and are connected to the pin 4 of the boost chip U2, the capacitor C7 and the inductor L2 are connected in series and are connected to the pins 5 and 4 of the boost chip U2 respectively, and the MOS tube Q1 is connected to the boost chip U2. The tail plate MCU control sub-circuit comprises a single-chip microcomputer U7, a diode D9, keys S1 and S2, a resistor R4, and capacitors C4, C5 and C6, the resistor R4 and the capacitor C4 are connected in series and are connected in parallel with the capacitors C5 and C6 and are connected to the pins 5 and 6 of the single-chip microcomputer U7 respectively, the key S1 is connected to the pin 10 of the single-chip microcomputer U7, the key S2 and the diode D9 are connected in series and are connected to the pin 11 of the single-chip microcomputer U7, the other ends of the keys S1 and S2 are grounded, and the MOS tube Q1 is connected to the single-chip microcomputer U7.

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