Single-chip microcomputer wireless data transmission weighing device

Abstract

A single-chip microcomputer wireless data transmission weighing device comprises a single-chip microcomputer U1, a system power supply circuit, a data storage circuit, a force sensor data sampling circuit, an LORA wireless data transmission circuit, a system indicating lamp circuit and an on-off control circuit. The single-chip microcomputer U1 is electrically connected with the system power supply circuit, the data storage circuit, the force sensor data sampling circuit, the LORA wireless data transmission circuit, the system indicating lamp circuit and the startup and shutdown control circuit. The system power supply circuit comprises a voltage reduction chip U3, a voltage boosting chip U4, a resistor R12, a resistor R13, a resistor R14, an inductor L1 and a diode D4. A traditional wired connection mode needs a large amount of manpower and material resources in installation and maintenance, and reliability and stability of the system are improved. The transmission distance of the wireless data transmission weighing device can be used for long-distance data transmission; and the wireless transmission system reduces the requirement of physical connection, so that the maintenance difficulty and cost of the system are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of object weighing, in particular to a single chip computer wireless data transmission weighing device. Background Art

[0002] Traditional wired vehicle weighing devices rely on cables for data transmission, which not only limits the flexibility of their installation and use, but also increases the complexity and cost of maintenance, especially in environments with complex layouts or narrow spaces. Environmental factors will cause difficulties for wiring. Moreover, during the inspection and maintenance of physical lines, this not only increases labor costs, but may also lead to increased system downtime. In addition, the laying and connection of cables are not only time-consuming and labor-intensive, but also prone to unstable signal transmission due to environmental factors such as wear and aging, affecting the accuracy and real-time performance of weighing. In addition, and because the wiring of wired weighing devices is fixed, this limits their mobility and flexibility in space. Once the wiring is determined, changing the location or route may require rewiring. Therefore, wired devices are particularly inconvenient in situations that require frequent movement or remote monitoring, and cannot meet the needs of modern traffic management and logistics and transportation industries for efficient and convenient weighing.

[0003] Therefore, a single-chip wireless data transmission weighing device is needed to solve this problem. Utility Model Content

[0004] In view of the above situation, in order to overcome the defects of the prior art, the purpose of the utility model is to provide a single chip wireless data transmission weighing device, which effectively solves the above problems.

[0005] The technical solution is that the utility model includes a single-chip microcomputer U1, a system power supply circuit, a data storage circuit, a force sensor data sampling circuit, a LORA wireless data transmission circuit, a system indicator light circuit and a power on / off control circuit. The single-chip microcomputer U1 is electrically connected to the system power supply circuit, the data storage circuit, the force sensor data sampling circuit, the LORA wireless data transmission circuit, the system indicator light circuit and the power on / off control circuit respectively.

[0006] Furthermore, the system power supply circuit includes a buck chip U3, a boost chip U4, a resistor R12, a resistor R13, a resistor R14, an inductor L1, and a diode D4. One end of the resistor R12 is connected to pin 4 of the boost chip U4, pin 5 of the boost chip U4 is connected to the input voltage, the other end of the resistor R12 is connected to the input voltage, the common end of the resistor R13 and the resistor R14 is connected to pin 3 of the boost chip U4, the parallel connection point of the resistor R13 and the other end of the resistor R14 is connected to pin 1 of the buck chip U3, and the other end of the resistor R14 is connected to the negative electrode, and the two ends of the capacitor C11 are respectively connected to one end of the resistor R14 connected to the negative electrode and one end of the resistor R13 connected to the buck chip U3. , capacitor C13 is connected in parallel at both ends of capacitor C11, one end of inductor L1 is connected to the input voltage, the other end of inductor L1 is connected to the anode of diode D4, pin 1 of boost chip U4 is connected to the common end of inductor L1 and diode D4, the cathode of diode D4 is connected to the series connection point of resistor R13 and pin 1 of buck chip U3, pin 5 of buck chip is connected to the single-chip computer and data storage circuit, pin 2 of buck chip U3 is connected to the cathode, and also includes capacitor C9, capacitor C11, capacitor C12 and capacitor C13, one end of capacitor C9 and capacitor C12 are connected to pin 5 of buck chip U3, the other end of capacitor C9 and capacitor C12 are connected to pin 2 of buck chip U3 and connected to the cathode.

[0007] Furthermore, the system power supply circuit is connected with a plug-in interface P1, and pins 1 and 2 of the plug-in interface P1 are connected to the positive and negative electrodes of the lithium battery.

[0008] Furthermore, the data storage circuit includes a data storage chip U2, wherein pin 8 of the data storage chip U2 is connected to the voltage output terminal of the step-down chip U3, and pin 5 and pin 6 of the data storage chip U2 are respectively connected to pin 32 and pin 33 of the microcontroller U1.

[0009] Furthermore, the force sensor data sampling circuit includes a data sampling chip U5 and an external interface plug-in P4, pins 15 and 16 of the data sampling chip U5 are respectively connected to pins 16 and 17 of the microcontroller, and pins 4 and 3 of the external interface plug-in P4 are respectively connected to pins 8 and 7 of the data sampling chip U5.

[0010] Furthermore, the LORA wireless data transmission circuit includes a LORA wireless communication chip U6, pin 1 and pin 2 of the LORA wireless communication chip U6 are respectively connected to pin 15 and pin 12 of the single-chip microcomputer U1, pin 3 and pin 4 of the LORA wireless communication chip U6 are respectively connected to pin 13 and pin 14 of the single-chip microcomputer U1, and pin 5 of the LORA wireless communication chip U6 is connected to pin 11 of the single-chip microcomputer U1.

[0011] Furthermore, the system indicator light circuit includes a resistor R15, a resistor R25, a resistor R27, a MOS tube Q3 and an LED diode D5, one end of the resistor R25 is connected to the pin 25 of the single-chip computer U1, one end of the resistor R15 is connected to the input voltage, the other end of the resistor R is connected to the anode of the LED diode D5, the cathode of the LED diode D5 is connected to the source of the MOS tube Q3, the other end of the resistor R25 is connected to the gate of the MOS tube Q3, one end of the resistor R27 is connected to the gate of the MOS tube Q3, the other end of the resistor R27 is connected to the drain of the MOS tube Q3 and connected to the cathode, and a parasitic diode is provided on the MOS tube Q3.

[0012] Further, the switch control circuit includes a MOS tube Q1, a MOS tube Q2, a lithium battery, a diode D2, a diode D3, a switch S1, a resistor R2, a resistor R3, a resistor R6, a resistor R8 and a resistor R9, the source of the MOS tube Q1 is connected to the first input voltage, the gate of the MOS tube Q1 is connected to the source of the MOS tube Q2, the drain of the MOS tube Q1 is connected to pin 2 of the plug-in interface P1, the two ends of the resistor R2 are respectively connected to the drain of the MOS tube Q1 and the gate of the MOS tube Q1, the gate of the MOS tube Q2 is connected to the resistor R8, the other end of the resistor R8 is connected to pin 24 of the single-chip computer U1, the drain of the MOS tube Q2 is connected to the cathode, the two ends of the resistor R9 are respectively connected to the gate and drain of the MOS tube Q2, the anode of the diode D3 is connected to the gate and The series connection point of the source of the MOS tube Q2 is connected, the anode of the diode D2 is connected to the resistor R3, the other end of the resistor R3 is connected to the second input voltage, the pin 23 of the single-chip computer U1 is connected to the series connection point of the diode D2 and the resistor R3, the cathodes of the diode D2 and the diode D3 are simultaneously connected to one end of the switch S1, the other end of the switch S1 is connected to the negative electrode, the capacitor C5 is connected in parallel to the switch S1, one end of the resistor R6 is connected to the pin 21 of the single-chip computer U1, the other end of the resistor R6 is connected to the first input voltage, the series connection point of the resistor R6 and the pin 21 of the single-chip computer U1 is connected to the negative electrode through the resistor R7, the capacitor C3 is connected to the pin 21 of the single-chip computer U1, the other end of the capacitor C3 is connected to the negative electrode, the capacitor C1 is connected to the first input voltage, and the other end of the capacitor C1 is connected to the negative electrode.

[0013] The beneficial effects of the utility model are:

[0014] 1. Convenience: Due to the use of wireless transmission technology, this device can realize remote data transmission without complicated wiring, which is widely used in mobile occasions such as driving scales and vehicle-mounted scales;

[0015] 2. Efficiency: Traditional wired connection methods require a lot of manpower and material resources for installation and maintenance, while wireless transmission systems reduce these requirements, reduce errors during installation and maintenance, and improve system reliability and stability;

[0016] 3. Long-distance transmission: The transmission distance of wireless data transmission weighing devices can carry out long-distance data transmission, which makes them very suitable for use in places where wired connections are difficult to make;

[0017] 4. Easy maintenance: The wireless transmission system reduces the need for physical connections, thereby reducing the difficulty and cost of system maintenance, and also reduces the use of wires, thereby reducing safety hazards caused by aging or damage of wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a principle block diagram of the utility model.

[0019] Figure 2 The utility model is a single chip microcomputer circuit diagram.

[0020] Figure 3 It is a power supply circuit diagram of the utility model.

[0021] Figure 4 The utility model is a data storage circuit diagram.

[0022] Figure 5 The utility model is a force sensor data sampling circuit diagram.

[0023] Figure 6 This is a LORA wireless data transmission circuit diagram of the utility model.

[0024] Figure 7 The utility model is a circuit diagram of a system indicator light.

[0025] Figure 8 The utility model is a switch control circuit diagram. DETAILED DESCRIPTION

[0026] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings.

[0027] Example:

[0028] Depend on Figures 1 to 8 It is given that the utility model includes a single-chip microcomputer U1, a system power supply circuit, a data storage circuit, a force sensor data sampling circuit, a LORA wireless data transmission circuit, a system indicator light circuit and a power on / off control circuit. The single-chip microcomputer U1 is electrically connected to the system power supply circuit, the data storage circuit, the force sensor data sampling circuit, the LORA wireless data transmission circuit, the system indicator light circuit and the power on / off control circuit respectively.

[0029] Specifically, the system power supply circuit includes a buck chip U3, a boost chip U4, a resistor R12, a resistor R13, a resistor R14, an inductor L1, and a diode D4. One end of the resistor R12 is connected to pin 4 of the boost chip U4, and pin 5 of the boost chip U4 is connected to the input voltage, which can be provided by a lithium battery. The other end of the resistor R12 is connected to the input voltage, and the common end of the resistor R13 and the resistor R14 is connected to pin 3 of the boost chip U4. The common end of the resistor R13 and the other end of the resistor R14 are connected in parallel. The connection point is connected to pin 1 of the buck chip U3, and the other end of the resistor R14 is connected to the negative electrode, so that the boost chip U4 is the input voltage of the buck chip U3, and the output of the boost chip U4 is connected to the force sensor data sampling circuit, the LORA wireless data transmission circuit, and the system indicator light circuit and powered. In addition, the resistors R13 and R14 can realize the feedback voltage divider circuit of the boost chip U4 so that the output voltage can reach 5V DC voltage. The two ends of the capacitor C11 are respectively connected to one end of the resistor R14 connected to the negative electrode and the resistor R13 is connected to one end of the buck chip U3, capacitor C13 is connected in parallel at both ends of capacitor C11, capacitor C11 and capacitor C13 can filter, so that the boost chip U4 remains stable during the discharge process, one end of the inductor L1 is connected to the input voltage, the other end of the inductor L1 is connected to the anode of the diode D4, pin 1 of the boost chip U4 is connected to the common end of the inductor L1 and the diode D4, the cathode of the diode D4 is connected to the series connection point of the resistor R13 and the pin 1 of the buck chip U3, and the pin 5 of the buck chip It is connected to the single-chip microcomputer and the data storage circuit so that the output voltage of the buck chip U3 powers the single-chip microcomputer and the data storage circuit. Pin 2 of the buck chip U3 is connected to the negative electrode. It also includes capacitor C9, capacitor C11, capacitor C12 and capacitor C13. One end of capacitor C9 and capacitor C12 are connected to pin 5 of the buck chip U3, and the other end of capacitor C9 and capacitor C12 are connected to pin 2 of the buck chip U3 and connected to the negative electrode. Capacitor C9 and capacitor C12 can perform filtering to keep the buck chip U3 stable during the discharge process.

[0030] It should be noted that the system power supply circuit is connected with a plug-in interface P1, and pins 1 and 2 of the plug-in interface P1 are connected to the positive and negative electrodes of the lithium battery, so that the lithium battery provides input voltage for the system power supply circuit.

[0031] Specifically, the data storage circuit includes a data storage chip U2, wherein pin 8 of the data storage chip U2 is connected to the voltage output end of the step-down chip U3, pin 5 and pin 6 of the data storage chip U2 are respectively connected to pin 32 and pin 33 of the single-chip computer U1, and pin 33 of the single-chip computer U1 provides the clock signal required for normal operation to pin 6 of the storage chip U2 in the data storage circuit, and the data storage chip U2 can write or read data through pin 5 according to the level change of pin 32 of the single-chip computer U1.

[0032] Specifically, the force sensor data sampling circuit includes a data sampling chip U5 and an external interface plug-in P4. Pins 15 and 16 of the data sampling chip U5 are respectively connected to pins 16 and 17 of the single-chip microcomputer. Pin 16 of the single-chip microcomputer U1 provides the clock signal required for normal operation for pin 15 of the data sampling chip U5. Pin 16 of the data sampling chip U5 outputs the detected force sensor signal, and the signal realizes data reading through pin 17 of the single-chip microcomputer U1. Pins 4 and 3 of the external interface plug-in P4 are respectively connected to pins 8 and 7 of the data sampling chip U5.

[0033] Specifically, the LORA wireless data transmission circuit includes a LORA wireless communication chip U6, pin 1 and pin 2 of the LORA wireless communication chip U6 are respectively connected to pin 15 and pin 12 of the single-chip microcomputer U1, and the level state of the pin is configured to change the working mode of the LORA wireless data transmission module through the LORA wireless communication chip, and pin 3 and pin 4 of the LORA wireless communication chip U6 are respectively connected to pin 13 and pin 14 of the single-chip microcomputer U1, so that the single-chip microcomputer U1 completes the data reception of the internal LORA wireless data transmission module and the external data sending work, and the 5th pin of the LORA wireless communication chip U6 is connected to the 11th pin of the single-chip microcomputer U1 for data communication.

[0034] In addition, the system indicator light circuit includes a resistor R15, a resistor R25, a resistor R27, a MOS tube Q3 and an LED diode D5, one end of the resistor R25 is connected to the pin 25 of the single-chip computer U1 for the control function interface, one end of the resistor R15 is connected to the input voltage, the other end of the resistor R is connected to the anode of the LED diode D5, the cathode of the LED diode D5 is connected to the source of the MOS tube Q3, the other end of the resistor R25 is connected to the gate of the MOS tube Q3, one end of the resistor R27 is connected to the gate of the MOS tube Q3, the other end of the resistor R27 is connected to the drain of the MOS tube Q3 and connected to the cathode, and a parasitic diode is provided on the MOS tube Q3.

[0035] It should be noted that the switch control circuit includes a MOS tube Q1, a MOS tube Q2, a lithium battery, a diode D2, a diode D3, a switch S1, a resistor R2, a resistor R3, a resistor R6, a resistor R8 and a resistor R9, the source of the MOS tube Q1 is connected to the first input voltage, the gate of the MOS tube Q1 is connected to the source of the MOS tube Q2, the drain of the MOS tube Q1 is connected to the pin 2 of the plug-in interface P1, and the two ends of the resistor R2 are respectively connected to the drain of the MOS tube Q1 and the gate of the MOS tube Q1. The gate of the MOS tube Q2 is connected to the resistor R8. Both the MOS tube Q1 and the MOS tube Q2 are provided with parasitic diodes. The other end of the resistor R8 is connected to the pin 24 of the single-chip computer U1. The I / O mode of the single-chip computer pin is push-pull output, which is used to output high and low levels to control the conduction of the NMOS tube. The drain of the MOS tube Q2 is connected to the cathode. The two ends of the resistor R9 are respectively connected to the gate and drain of the MOS tube Q2. The anode of the diode D3 is connected in series with the gate of the MOS tube Q1 and the source of the MOS tube Q2. The anode of the diode D2 is connected to the resistor R3, and the other end of the resistor R3 is connected to the second input voltage. The pin 23 of the single-chip computer U1 is connected to the series connection point of the diode D2 and the resistor R3, wherein the I / O mode of the single-chip computer pin 23 is a floating input, which is used to detect the time when the touch switch button is pressed. The cathodes of the diodes D2 and D3 are simultaneously connected to one end of the switch S1, and the other end of the switch S1 is connected to the negative electrode. The capacitor C5 is connected in parallel to the switch S1 for filtering. One end of the resistor R6 It is connected to pin 21 of the microcontroller U1, where the I / O mode of the microcontroller pin is analog input, which is used to detect the voltage of the lithium battery. The other end of the resistor R6 is connected to the first input voltage, and the series connection point of the resistor R6 and the pin 21 of the microcontroller U1 is connected to the negative electrode through the resistor R7. The pin 21 of the microcontroller U1 is connected to a capacitor C3, and the other end of the capacitor C3 is connected to the negative electrode. The first input voltage is connected to a capacitor C1, and the other end of the capacitor C1 is connected to the negative electrode. The function of the capacitor C1 and the capacitor C3 is filtering.

[0036] In this embodiment, the single-chip computer U1 can adopt the STM32G030C8T6 chip, the data storage chip U2 can adopt the FM24C32 data storage chip, the step-down chip U3 can adopt the XC6219B332MR chip, the boost chip U4 can adopt the MT3608 chip, the data sampling chip U5 can adopt the ADS1230 analog-to-digital conversion chip, and the LORA wireless communication chip U6 can adopt the LLCC68 radio frequency chip.

[0037] The beneficial effects of the utility model are:

[0038] 1. Convenience: Due to the use of wireless transmission technology, this device can realize remote data transmission without complicated wiring, which is widely used in mobile occasions such as driving scales and vehicle-mounted scales;

[0039] 2. Efficiency: Traditional wired connection methods require a lot of manpower and material resources for installation and maintenance, while wireless transmission systems reduce these requirements, reduce errors during installation and maintenance, and improve system reliability and stability;

[0040] 3. Long-distance transmission: The transmission distance of wireless data transmission weighing devices can carry out long-distance data transmission, which makes them very suitable for use in places where wired connections are difficult to make;

[0041] 4. Easy maintenance: The wireless transmission system reduces the need for physical connections, thereby reducing the difficulty and cost of system maintenance, and also reduces the use of wires, thereby reducing safety hazards caused by aging or damage of wires.

[0042] In summary, the single-chip wireless data transmission weighing device has significant advantages in convenience, efficiency, long-distance transmission, intelligent control, versatility, device maintenance, and safety. It is an important tool for weighing devices in modern industry and daily life.

[0043] The above-mentioned specific implementation modes / embodiments are specific implementation modes of the utility model, which are used to illustrate the concept of the utility model, are explanatory and exemplary, and should not be interpreted as limiting the implementation modes of the utility model and the scope of the utility model. In addition to the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims and the specification of this application. These technical solutions include technical solutions that make any obvious replacements and modifications to the embodiments described herein, which are within the scope of protection of the utility model. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The utility model is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A single chip computer wireless data transmission weighing device, characterized in that: It includes a single-chip microcomputer U1, a system power supply circuit, a data storage circuit, a force sensor data sampling circuit, a LORA wireless data transmission circuit, a system indicator light circuit and a power on / off control circuit. The single-chip microcomputer U1 is electrically connected to the system power supply circuit, the data storage circuit, the force sensor data sampling circuit, the LORA wireless data transmission circuit, the system indicator light circuit and the power on / off control circuit respectively.

2. A single chip microcomputer wireless data transmission weighing device according to claim 1, characterized in that: The system power supply circuit includes a buck chip U3, a boost chip U4, a resistor R12, a resistor R13, a resistor R14, an inductor L1, and a diode D4. One end of the resistor R12 is connected to pin 4 of the boost chip U4, pin 5 of the boost chip U4 is connected to the input voltage, the other end of the resistor R12 is connected to the input voltage, the common end of the resistor R13 and the resistor R14 is connected to pin 3 of the boost chip U4, the parallel connection point of the resistor R13 and the other end of the resistor R14 is connected to pin 1 of the buck chip U3, and the other end of the resistor R14 is connected to the negative electrode, and the two ends of the capacitor C11 are respectively connected to one end of the resistor R14 connected to the negative electrode and one end of the resistor R13 connected to the buck chip U3. Capacitor C13 is connected in parallel at both ends of capacitor C11, one end of inductor L1 is connected to the input voltage, the other end of inductor L1 is connected to the anode of diode D4, pin 1 of boost chip U4 is connected to the common end of inductor L1 and diode D4, the cathode of diode D4 is connected to the series connection point of resistor R13 and pin 1 of buck chip U3, pin 5 of buck chip is connected to the single-chip computer and data storage circuit, pin 2 of buck chip U3 is connected to the cathode, capacitor C9, capacitor C11, capacitor C12 and capacitor C13 are also included, one end of capacitor C9 and capacitor C12 are connected to pin 5 of buck chip U3, the other end of capacitor C9 and capacitor C12 are connected to pin 2 of buck chip U3 and connected to the cathode.

3. A single chip microcomputer wireless data transmission weighing device according to claim 2, characterized in that: The system power supply circuit is connected with a plug-in interface P1, and pins 1 and 2 of the plug-in interface P1 are connected to the positive and negative electrodes of the lithium battery.

4. A single chip microcomputer wireless data transmission weighing device according to claim 1, characterized in that: The data storage circuit includes a data storage chip U2, wherein pin 8 of the data storage chip U2 is connected to the voltage output terminal of the step-down chip U3, and pins 5 and 6 of the data storage chip U2 are respectively connected to pins 32 and 33 of the microcontroller U1.

5. The single chip computer wireless data transmission weighing device according to claim 1, characterized in that: The force sensor data sampling circuit includes a data sampling chip U5 and an external interface plug-in P4. Pins 15 and 16 of the data sampling chip U5 are respectively connected to pins 16 and 17 of the single-chip microcomputer, and pins 4 and 3 of the external interface plug-in P4 are respectively connected to pins 8 and 7 of the data sampling chip U5.

6. A single chip microcomputer wireless data transmission weighing device according to claim 1, characterized in that: The LORA wireless data transmission circuit includes a LORA wireless communication chip U6, pin 1 and pin 2 of the LORA wireless communication chip U6 are respectively connected to pin 15 and pin 12 of the single-chip microcomputer U1, pin 3 and pin 4 of the LORA wireless communication chip U6 are respectively connected to pin 13 and pin 14 of the single-chip microcomputer U1, and pin 5 of the LORA wireless communication chip U6 is connected to pin 11 of the single-chip microcomputer U1.

7. A single chip computer wireless data transmission weighing device according to claim 1, characterized in that: The system indicator light circuit includes a resistor R15, a resistor R25, a resistor R27, a MOS tube Q3 and an LED diode D5. One end of the resistor R25 is connected to the pin 25 of the single-chip computer U1, one end of the resistor R15 is connected to the input voltage, the other end of the resistor R is connected to the anode of the LED diode D5, the cathode of the LED diode D5 is connected to the source of the MOS tube Q3, the other end of the resistor R25 is connected to the gate of the MOS tube Q3, one end of the resistor R27 is connected to the gate of the MOS tube Q3, the other end of the resistor R27 is connected to the drain of the MOS tube Q3 and connected to the cathode, and a parasitic diode is provided on the MOS tube Q3.

8. The single chip computer wireless data transmission weighing device according to claim 3 is characterized in that: The switch control circuit includes a MOS tube Q1, a MOS tube Q2, a lithium battery, a diode D2, a diode D3, a switch S1, a resistor R2, a resistor R3, a resistor R6, a resistor R8 and a resistor R9. The source of the MOS tube Q1 is connected to the first input voltage, the gate of the MOS tube Q1 is connected to the source of the MOS tube Q2, the drain of the MOS tube Q1 is connected to the pin 2 of the plug-in interface P1, the two ends of the resistor R2 are respectively connected to the drain of the MOS tube Q1 and the gate of the MOS tube Q1, the gate of the MOS tube Q2 is connected to the resistor R8, the other end of the resistor R8 is connected to the pin 24 of the single-chip computer U1, the drain of the MOS tube Q2 is connected to the cathode, the two ends of the resistor R9 are respectively connected to the gate and drain of the MOS tube Q2, the anode of the diode D3 is connected to the gate and the gate of the MOS tube Q1, and the gate of the MOS tube Q2 is connected to the resistor R8. The series connection point of the source of the S tube Q2 is connected, the anode of the diode D2 is connected to the resistor R3, the other end of the resistor R3 is connected to the second input voltage, the pin 23 of the single-chip computer U1 is connected to the series connection point of the diode D2 and the resistor R3, the cathodes of the diode D2 and the diode D3 are simultaneously connected to one end of the switch S1, the other end of the switch S1 is connected to the negative electrode, the capacitor C5 is connected in parallel to the switch S1, one end of the resistor R6 is connected to the pin 21 of the single-chip computer U1, the other end of the resistor R6 is connected to the first input voltage, the series connection point of the resistor R6 and the pin 21 of the single-chip computer U1 is connected to the negative electrode through the resistor R7, the pin 21 of the single-chip computer U1 is connected to the capacitor C3, the other end of the capacitor C3 is connected to the negative electrode, the first input voltage is connected to the capacitor C1, and the other end of the capacitor C1 is connected to the negative electrode.

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