High-reliability heating / heat dissipation automatic switching efficient power supply circuit

Abstract

According to the high-reliability heating / heat dissipation automatic switching efficient power supply circuit, the temperature of a radar equipment shell is sampled in real time through a thermistor, and when the temperature of the equipment shell is lower than a low-temperature set value, a heating circuit is started, a heating piece works, equipment is heated, and the temperature of the shell rises till the temperature reaches the low-temperature set value; if yes, the heating circuit is closed; when the temperature of the equipment shell is higher than a high-temperature set value, the heat dissipation circuit is started, the fan works, the equipment dissipates heat, the temperature of the shell is reduced, and when the temperature is reduced to the high-temperature set value, the heat dissipation circuit is closed; meanwhile, in order to ensure that the heating circuit or the heat dissipation circuit fails, a forced shutdown circuit is designed, during normal work, a power tube of the forced shutdown circuit is normally conducted, and work of the heating (or heat dissipation) circuit is not affected. Efficient switching of equipment heat dissipation and heating is achieved through one circuit, the size is small, and the circuit is efficient and reliable.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supplies, and particularly relates to a highly reliable heating / dissipating heat automatically switching and efficient power supply circuit. Background Art

[0002] In recent years, as an emerging weapon for future wars, unmanned aerial vehicles (UAVs) have been increasingly applied in radar based on unmanned platforms and have shown excellent performance in performing tasks. With the continuous expansion of the application fields of UAVs, the environments during mission execution have become increasingly complex. When operating on the ground or at low altitudes, the external environmental temperature is relatively high. Coupled with the heat generated by the radar equipment itself, the internal circuits of the radar will be in a high-temperature state, and heat dissipation measures need to be adopted to dissipate heat from the internal equipment. When the UAV is flying in the stratosphere, the external environmental temperature is very low. The extremely low environmental temperature will cause failures in the internal radar circuits, affecting the radar performance and even the service life of the radar. In order to ensure the reliable operation of the radar at low temperatures, heating measures need to be adopted to heat the internal radar equipment to avoid damage to the internal circuits of the radar caused by too low temperatures. Summary of the Invention

[0003] Therefore, the present invention provides a highly reliable heating / dissipating heat automatically switching and efficient power supply circuit, which realizes the efficient switching between equipment heat dissipation and heating through a set of circuits, has a small volume, and the circuit is highly efficient and reliable.

[0004] When the drone is flying in the stratosphere, the ambient temperature at night is very low, even dropping below -90°C. The radar equipment cannot work in such extreme environments and may even be damaged. Therefore, heating measures must be taken to heat and keep the equipment warm. When the drone is flying at low altitude during the day, the ambient temperature is relatively high, reaching above 70°C. Considering that the radar equipment itself is a high-power device and generates a large amount of heat on its own, cooling measures need to be adopted to dissipate the heat of the equipment. In the present invention, a thermistor is used to sample the temperature of the radar equipment housing in real time. When the temperature of the equipment housing itself is lower than the low-temperature set value, the heating circuit is activated, the heating element works, the equipment is heated, and the housing temperature rises until the temperature reaches the low-temperature set value, then the heating circuit is turned off. When the temperature of the equipment housing itself is higher than the high-temperature set value, the cooling circuit is activated, the fan works, the equipment dissipates heat, and the housing temperature drops. When the temperature drops to the high-temperature set value, the cooling circuit is turned off. When the temperature of the equipment housing is between the low-temperature set value and the high-temperature set value, neither the heating circuit nor the cooling circuit works, saving energy consumption. At the same time, to ensure the failure of the heating circuit or the cooling circuit, a forced shutdown circuit is designed. During normal operation, the power transistor of the forced shutdown circuit is normally conducting and does not affect the operation of the heating (or cooling) circuit. The system normally samples the temperature of the radar equipment housing and the heating (or cooling) current value. Once the temperature of the equipment housing reaches the set value, the heating (or cooling) is turned off. It is detected that the heating (or cooling) current value drops to zero, and the temperature change of the equipment housing slows down. If the heating (or cooling) circuit malfunctions and cannot be normally turned off at this time, it can be turned off through the externally added forced shutdown circuit of the system, improving the reliability of the circuit. In the present invention, MOS transistors are used as power transistors, and operational amplifiers are used in the control circuit. The internal resistance of the MOS transistor is relatively small (about a few milliohms to a dozen milliohms), and the heating (or cooling) circuit has a very high efficiency. The power transistor and the integrated circuit are both surface-mounted packages, and the circuit volume is very small, which is very convenient to install inside each equipment unit.

[0005] The present invention uses a thermistor to sample the temperature of the equipment housing, sets the temperature threshold using an operational amplifier circuit, and then switches through a high-efficiency MOS transistor to achieve the heating or cooling function. At the same time, the temperature and the heating (or cooling) current are reported. When an abnormality occurs, the heating (or cooling) circuit can be quickly turned off through the forced shutdown circuit, realizing autonomous heating of the equipment at low temperatures and autonomous cooling at high temperatures. The switching process is efficient and reliable.

[0006] The highly reliable heating / cooling automatic switching high-efficiency power circuit of the present invention includes six parts: an auxiliary power source circuit, a temperature sampling circuit, an automatic heating circuit, an automatic cooling circuit, a current sampling circuit, and a forced shutdown circuit.

[0007] The auxiliary source circuit consists of capacitor C1, resistors R1, R2, R3, and precision reference N2. One end of resistor R1 is connected to the positive terminal of the input power supply (VIN, external power supply), and the other end is connected to the cathode of reference N2. The anode of N2 is connected to the negative terminal of the input power supply (i.e., the input power supply ground). One end of resistors R2 and R3 are connected together and connected to the reference terminal of N2. The other end of resistor R2 is connected to the cathode of N2, and the other end of resistor R3 is connected to the negative terminal of the input power supply. One end of capacitor C1 (if it is a polarized capacitor, it is the positive electrode of the capacitor) is connected to the cathode of N2 and is also the positive terminal of the auxiliary source output (i.e., VCC). The other end of capacitor C1 (if it is a polarized capacitor, it is the negative electrode of the capacitor) is connected to the input power supply ground. By adjusting the resistance values of R2 and R3, the output voltage of the auxiliary source can be easily adjusted.

[0008] The temperature sampling circuit consists of capacitor C2, resistors R4, R5, R6, R7, thermistor RT, and integrated circuit N1B. One end of resistor R4 is connected to the positive terminal of the auxiliary source (VCC), and the other end is connected to the inverting terminal of integrated circuit N1B. The inverting terminal of N1B is also connected to one end of resistor R5 and one end of capacitor C2. The other end of capacitor C2 is connected to the negative terminal of the input power supply. The other end of resistor R5 is connected to one end of thermistor RT, and the other end of thermistor RT is connected to the negative terminal of the input power supply. One end of resistor R6 is connected to one end of resistor R7, and the connection end of R6 and R7 is simultaneously connected to the non-inverting terminal of integrated circuit N1B. The other end of resistor R6 is connected to the ground of the input power supply, and the other end of resistor R7 is connected to the output terminal of operational amplifier N1B. Thermistor RT is a negative temperature coefficient resistor, and the lower the temperature, the greater the resistance. At a given VCC, RT corresponds to different voltage values at different temperatures. By reasonably selecting the resistance values of resistors R4, R5, R6, R7, the output voltage value of operational amplifier N1B can linearly reflect the temperature (T in the figure) of the equipment housing.

[0009] The automatic heating circuit consists of a triode V1, a MOS transistor Q1, resistors R8, R9, R10, R11, R12, R13, R14, R15, an integrated circuit N1A, and a heating element (Heat in the figure). The output terminal of the operational amplifier N1B is connected to one end of the resistor R8, the other end of R8 is connected to the resistor R9, the connected end of the resistors R8 and R9 is connected to the non-inverting terminal of the operational amplifier N1A and one end of the resistor R12, the other end of the resistor R12 is connected to the output terminal of the operational amplifier N1A, one end of the resistor R10 is connected to one end of the resistor R11, the connected end of the resistors R10 and R11 is connected to the inverting terminal of the operational amplifier N1A, the other end of the resistor R10 is connected to the positive terminal of the auxiliary source (i.e., VCC), the other end of the resistor R11 is connected to the ground of the input power supply, the output terminal of the operational amplifier N1A is connected to one end of the resistor R13, the other end of the resistor R13 is connected to one end of the resistor R14 and the base of the triode V1, the other end of the resistor R14 is connected to the ground of the input power supply, the emitter of the triode V1 is connected to the ground of the input power supply, the source of the triode V1 is connected to one end of the resistor R15, the other end of the resistor R15 is connected to the gate of the MOS transistor Q1, the source of the MOS transistor Q1 is connected to the positive terminal of the input power supply (i.e., VIN), the drain of the MOS transistor Q1 is connected to one end of the heating element (i.e., Heat), the other end of the heating element is connected to one end of the resistor R0. The resistors R10 and R11 set the low-temperature voltage threshold. When the sampled temperature voltage is higher than the threshold value, the operational amplifier N1A outputs a high level, the triode V1 conducts, the MOS transistor Q1 conducts, and the heating element works.

[0010] The automatic heat dissipation circuit consists of MOS transistor Q2, resistors R16, R17, R18, R19, R20, R21, R22, integrated circuit N1C, and a fan (FAN in the figure). The output terminal of operational amplifier N1B is connected to one end of resistor R20. The other end of R20 is connected to resistor R17. The connecting end of resistors R20 and R17 is connected to the inverting terminal of operational amplifier N1C. The other end of resistor R17 is connected to the ground of the power supply. One end of resistor R16 is connected to one end of resistor R18. The connecting end of resistors R16 and R18 is connected to the non-inverting terminal of operational amplifier N1C and one end of resistor R19. The other end of resistor R16 is connected to the positive terminal of the auxiliary power supply (i.e., VCC). The other end of resistor R18 is connected to the ground of the input power supply. The other end of resistor R19 is connected to the output terminal of operational amplifier N1C. The output terminal of operational amplifier N1C is connected to one end of resistor R21. The other end of resistor R21 is connected to one end of resistor R22 and the gate of MOS transistor Q2. The other end of resistor R22 is connected to the source of Q2. The source of MOS transistor Q2 is connected to one end of the connection between resistor R0 and the heating element. The drain of MOS transistor Q2 is connected to the negative terminal of the fan (FAN). The positive terminal of the fan is connected to the positive terminal of the input power supply (i.e., VIN). Resistors R16 and R18 set the high-temperature voltage threshold. When the sampled temperature voltage is lower than the threshold value, operational amplifier N1C outputs a high level, MOS transistor Q2 conducts, and the fan works.

[0011] The current sampling circuit consists of resistors R23, R24, R25, R26, sampling resistor R0, and integrated circuit N1D. One end of sampling resistor R0 is connected to the drain of MOS transistor Q3, and the other end is connected to one end of resistor R23, the source of MOS transistor Q2, and one end of the heating element. The other end of resistor R23 is connected to one end of resistor R25. The connecting end of resistors R23 and R25 is connected to the non-inverting terminal of operational amplifier N1D. The other end of resistor R25 is connected to the ground of the output power supply. The connecting end of resistors R24 and R26 is connected to the inverting terminal of operational amplifier N1D. The other end of resistor R26 is connected to the ground of the input power supply. The other end of resistor R26 is connected to the output terminal of operational amplifier N1D. Sampling resistor R0 samples the current. Operational amplifier N1D and resistors R23, R24, R25, R26 form a differential amplification circuit to amplify the voltage signal on R0 and report the current value (I in the figure) to the upper-level system in real time.

[0012] The forced shutdown circuit consists of a triode V2, a MOS transistor Q3, and resistors R27, R28, R29, and R30. The positive input power supply (VIN) is connected to one end of resistor R29. The other end of resistor R29 is connected to the collector of triode V2, the gate of MOS transistor Q3, and one end of resistor R30. The other end of resistor R30 is connected to the emitter of triode V2, the source of MOS transistor Q3, and is connected to the ground of the input power supply. The drain of MOS transistor Q3 is connected to the sampling resistor R0. One end of the connection between resistor R27 and resistor R28 is connected to the base of triode V2. The other end of resistor R28 is connected to the ground of the input power supply. The forced shutdown signal K is input from the other end of resistor R27. During normal operation, triode V2 is not conducting. The voltage division of resistors R29 and R30 ensures that MOS transistor Q2 is conducting. When the upper-level system needs to force a shutdown, a high-level signal is input from one end of resistor R27, triode V2 conducts, the gate voltage of MOS transistor Q3 is pulled down (close to zero), MOS transistor Q3 turns off, and the heating (or cooling) circuit is turned off.

[0013] For the continuous and pulsed operation switching of components, a power supply mode mutual exclusion circuit and output voltage protection are designed. Through the power supply mode mutual exclusion circuit, it is ensured that only one power supply mode exists at the same time, achieving interlocking between working modes. Through output voltage protection, the safety during the high-voltage mode to low-voltage mode switching is ensured. Only when the output voltage drops to a lower voltage value can the switching action be completed. When the voltage has not dropped to a reasonable value, low-voltage operation must be prohibited. A thermistor samples the temperature of the device's heat dissipation component housing. The operational amplifier circuit sets a threshold, and then it is switched to the heating circuit or the cooling circuit through a high-efficiency MOS transistor. At the same time, the temperature and the heating (or cooling) current are reported. In case of an abnormality, the heating (or cooling) circuit can be quickly turned off through the forced shutdown circuit. It can achieve autonomous heating of the device at low temperatures, autonomous cooling at high temperatures, and can be forced to quickly switch in case of circuit abnormalities. The circuit works efficiently and reliably during the operation process.

[0014] The beneficial effects of the present invention are as follows

[0015] 1. Automatic switching between the heating and cooling working modes can be achieved

[0016] The temperature of the radar device housing is sampled in real time through a thermistor. When the temperature of the device housing itself is lower than the low-temperature set value, the heating circuit is activated, the heating element works, the device is heated, and the housing temperature rises. When the temperature reaches the low-temperature set value, the heating circuit is turned off. When the temperature of the device housing itself is higher than the high-temperature set value, the cooling circuit is activated, the fan works, the device is cooled, and the housing temperature drops. When the temperature drops to the high-temperature set value, the cooling circuit is turned off. When the temperature of the device housing is between the low-temperature set value and the high-temperature set value, neither the heating circuit nor the cooling circuit works, saving energy consumption. The device compares with the sampled temperature based on the low-temperature set value and the high-temperature set value, and autonomously switches the working mode.

[0017] 2. High power density of the device heating and cooling circuits can be achieved

[0018] In the circuit of the present invention, all control circuits use surface mount devices. Among them, the power transistor uses a MOS transistor, and the control circuit uses an operational amplifier. The internal resistance of the MOS transistor is relatively small (about a few milliohms to a dozen milliohms), the heating (or cooling) circuit has high efficiency, and both the power transistor and the integrated circuit use surface mount packages. The circuit volume is very small and it is very convenient to install inside each device unit, and the power density of the heating and cooling circuits is high.

[0019] 3. Forced shutdown circuit to ensure high reliability during the switching process

[0020] To prevent the heating circuit or the cooling circuit from failing, the circuit of the present invention designs a forced shutdown circuit. During normal operation, the MOS transistor of the forced shutdown circuit is normally conducting and does not affect the operation of the heating (or cooling) circuit. The system normally collects the temperature of the radar device housing and the heating (or cooling) current value. Once the temperature of the device housing reaches the set value, the heating (or cooling) is turned off. It is detected that the heating (or cooling) current value drops to zero, and the temperature change of the device housing slows down. If the heating (or cooling) circuit malfunctions at this time and the heating (or cooling) current value does not drop to zero (i.e., it cannot be normally turned off), it can be turned off through the external forced shutdown circuit of the system, improving the reliability of the circuit.

[0021] 4. Report the temperature and heating (or cooling) current in real time for convenient system monitoring

[0022] In the circuit of the present invention, the voltage value corresponding to the sampled temperature of the device housing and the heating (or cooling) current value are reported in real time. The device receives the temperature value and the current value, and can monitor the working condition of the circuit in real time. Description of the Drawings

[0023] Figure 1 This is the circuit diagram of the present invention.

[0024] The meanings of the reference numerals are as follows: Box 1 is the auxiliary power supply circuit, Box 2 is the temperature sampling circuit, Box 3 is the automatic heating circuit, Box 4 is the automatic cooling circuit, Box 5 is the current sampling circuit, and Box 6 is the forced shutdown circuit.

[0025] The capacitor C1, resistors R1, R2, R3, and the integrated circuit N2 form the auxiliary power supply circuit; the capacitor C2, resistors R4, R5, R6, R7, the thermistor RT, and the integrated circuit N1B form the temperature sampling circuit; the triode V1, MOS transistor Q1, resistors R8, R9, R10, R11, R12, R13, R14, R15, the integrated circuit N1A, and the heating element Heat form the automatic heating circuit; the MOS transistor Q2, resistors R16, R17, R18, R19, R20, R21, R22, the integrated circuit N1C, and the fan FAN form the automatic cooling circuit; the resistors R23, R24, R25, R26, the sampling resistor R0, and the integrated circuit N1D form the current sampling circuit; the triode V2, MOS transistor Q3, and resistors R27, R28, R29, R30 form the forced shutdown circuit. Detailed implementation manners

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0027] As Figure 1 shown, the external power supply VIN is 28V. In the auxiliary power supply circuit, N2 is a 431 voltage reference. The integrated circuit GFW431BFZ (manufactured by Zhenhua Fengguang Semiconductor Co., Ltd.) is selected. The resistor R2 is selected as RMK1608 - 20kΩ, R3 is selected as RMK1608 - 5.1kΩ, the resistor R1 is selected as RMK6332 - 750Ω, the capacitor C1 is selected as GCT41G - 0603 - X7S - 10V - 4.7uF - K, and the auxiliary power supply output voltage VCC is 12V, with a load - carrying capacity of about 20mA.

[0028] The operational amplifiers N1A - N1D in the temperature sampling circuit, automatic heating circuit, automatic cooling circuit and current sampling circuit are all four - way operational amplifiers. The integrated circuit GF124ASLZ (Tianshui Tianguang Semiconductor Co., Ltd.) is selected. The thermistor RT is selected as GSWF16C (QJMF514C01 - 3950)-10kΩ (manufactured by Chengdu Hongming Electronics Co., Ltd.). The thermistor RT is directly installed at the temperature measuring point of the machine shell. R4 is RMK1608 - 33kΩ, R5 is RMK1608 - 820Ω, R6 is RMK1608 - 20kΩ, R7 is RMK1608 - 1kΩ. The thermistor RT is a negative temperature coefficient thermistor, the lower the temperature, the larger the resistance. At - 40°C, the corresponding resistance is about 210kΩ, and at + 70°C, the corresponding resistance is about 2kΩ. The high - temperature heat dissipation point is set at 70°C. At this time, the output voltage value of the operational amplifier N1B (T in the figure) is 1V. The low - temperature heating point is set at - 40°C. At this time, the output voltage value of the operational amplifier N1B (T in the figure) is 10.9V. The output voltage value of the operational amplifier is linearly related to the temperature.

[0029] In the automatic heating circuit, R8 is selected as RMK1608 - 13.7kΩ, R11 is selected as RMK1608 - 13kΩ, R9 and R10 are selected as RMK1608 - 15kΩ, R13 and R15 are selected as RMK1608 - 10kΩ, R14 is selected as RMK1608 - 1kΩ. The triode V1 is selected as BCX41S (manufactured by China Zhenhua Group Yongguang Electronics Co., Ltd.), Q1 is selected as PMOS tube JSD805C (58th Institute of China Electronics Technology Corporation). R12 is selected as RMK1608 - 510kΩ. R12 adds a hysteresis voltage (about 0.3V) to the operational amplifier. The comparison reference level set at the inverting terminal of the operational amplifier N1A is 5.6V. When the voltage at the non - inverting terminal of N1A is higher than the reference value at the inverting terminal, it flips. The voltage at the non - inverting terminal of the operational amplifier N1A is determined by the output voltage of the operational amplifier N1B and the voltage division of the resistors R8 and R9. At the low - temperature heating set point of - 40°C, the voltage at the inverting terminal of N1A is slightly greater than 5.6V. At this time, the operational amplifier N1A flips, changing from low level to high level. The triode V1 conducts, and the PMOS tube Q1 conducts, and the heating element starts to work. The lower the temperature, the higher the output voltage value of the operational amplifier N1B. The operational amplifier N1B maintains a high voltage (greater than 10.9V), and the heating circuit continues to work. After the heating circuit works, the temperature rises. When the voltage at the non - inverting terminal of the operational amplifier N1B drops below 5.3V (hysteresis voltage about 0.3V), the output of the operational amplifier N1B flips again from high level to low level, and the heating circuit stops working. The heating circuit works automatically according to the set low - temperature voltage threshold.

[0030] In the automatic heat dissipation circuit, R16 and R17 are selected as RMK1608 - 12kΩ, R18, R20 and R21 are selected as RMK1608 - 1kΩ, R22 is selected as RMK1608 - 10kΩ, R19 is selected as RMK1608 - 910kΩ. R19 adds a hysteresis voltage (about 0.1V) to the operational amplifier. Q2 is selected as the NMOS transistor LN06N010J (manufactured by Xi'an Longfei Electric Technology Co., Ltd.). The reference level at the non-inverting terminal of the operational amplifier N1C is 0.9V. When the voltage at the inverting terminal of the operational amplifier N1C is lower than the reference value at the non-inverting terminal, it flips. The voltage at the inverting terminal of the operational amplifier N1C is determined by the output voltage of N1B and the voltage division of resistors R17 and R20. The high-temperature heat dissipation set point of +70°C corresponds to a voltage of 0.92V at the inverting terminal of N1C. At this time, the operational amplifier N1C flips from low level to high level, Q2 conducts, and the fan starts to work (the fan supply voltage is 28V). The higher the temperature, the lower the output voltage value of the operational amplifier N1B. When the output voltage of the operational amplifier N1B is relatively low (lower than 1V), the heat dissipation circuit continues to work. After the fan starts working, the temperature drops, the voltage at the non-inverting terminal of the operational amplifier N1B rises, and the voltage at the inverting terminal of the operational amplifier N1C rises. When it reaches 1V (hysteresis voltage about 0.1V), the output of the operational amplifier N1C flips again from high level to low level, and the heat dissipation circuit stops working. The heat dissipation circuit works automatically according to the set high-temperature voltage threshold.

[0031] In the current sampling circuit, R0 is the sampling resistor selected as JMA25A3FR002T (manufactured by Nanjing Sate Technology Development Co., Ltd.), with a resistance value of 2mΩ. R23 and R24 are selected as RMK1608 - 1kΩ, and R25 and R26 are selected as RMK1608 - 100kΩ. The operational amplifier N1D and resistors R23, R24, R24 and R26 form a differential amplifier circuit with an amplification factor of 101 times. When 10A passes through R0, the sampled current value is 2.02V. The output current sampling value is proportional to the voltage across R0. In this example, when the current is not greater than 10A, the sampling value is less than 2V. The superior system can accurately calculate the real-time working current value of the heating or heat dissipation circuit through the sampling value.

[0032] In the forced shutdown circuit, resistors R29 and R30 are selected as RMK2012 - 10kΩ, resistor R27 is selected as RMK1608 - 2.7kΩ, resistor R28 is selected as RMK1608 - 1kΩ, V2 is selected as BCX41S (manufactured by China Zhenhua Group Yongguang Electronics Co., Ltd.), and Q3 is selected as the NMOS transistor LN06N010J (manufactured by Xi'an Longfei Electric Technology Co., Ltd.).

[0033] During normal operation, the forced shutdown level is low, the triode V2 is not conducting, and the NMOS transistor Q3 is turned on by the voltage division of R29 and R30, and the heating or cooling circuit operates normally. When the forced shutdown level is high (about 5V), V2 conducts, and at this time the voltage at the G pole of the NMOS is pulled to near ground level, and the NMOS transistor Q3 is short-circuited, and the heating or cooling circuit is turned off. When the thermistor detects the low temperature set temperature (-40 °C), the heating circuit automatically operates; when the thermistor detects the high temperature set temperature (-70 °C), the cooling circuit automatically operates; at the same time, the current value during operation is reported in real time; when the superior system determines that the heating or cooling operation is abnormal, the heating or cooling circuit can be turned off through the forced shutdown circuit.

[0034] The present invention is not limited to the above specific embodiments, and the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention shall be included in the protection scope of the present invention.

Claims

1. A highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit, characterized in that: It includes an auxiliary power source circuit, a temperature sampling circuit, an automatic heating circuit, an automatic cooling circuit, a current sampling circuit, and a forced shutdown circuit; The auxiliary power source circuit provides power output for each circuit; The temperature sampling circuit samples the device temperature through a thermistor; The automatic heating circuit automatically turns on the heating element for heating when the sampled temperature voltage is higher than the threshold value; The automatic cooling circuit automatically turns on the fan for cooling when the sampled temperature voltage is lower than the threshold value; The current sampling circuit collects the current value in the circuit and reports it to the upper-level system in real time; The forced shutdown circuit shuts down the automatic heating or automatic cooling circuit when the upper-level system needs to perform a forced shutdown.

2. The highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 1, wherein: The auxiliary power source circuit consists of capacitor C1, resistors R1, R2, R3, and reference N2. One end of resistor R1 is connected to the positive terminal of the input power supply VIN, and the other end is connected to the cathode of reference N2. The anode of N2 is connected to the negative terminal of the input power supply. One end of resistors R2 and R3 are connected together and connected to the reference terminal of reference N2. The other end of resistor R2 is connected to the cathode of reference N2, and the other end of resistor R3 is connected to the negative terminal of the input power supply. One end of capacitor C1 is connected to the cathode of reference N2 and serves as the positive terminal of the auxiliary power source output at the same time. The other end of capacitor C1 is connected to the input power supply ground. By adjusting the resistance values of resistors R2 and R3, the magnitude of the auxiliary power source output voltage can be adjusted.

3. The highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 2, wherein: The temperature sampling circuit consists of capacitor C2, resistors R4, R5, R6, R7, thermistor RT, and operational amplifier N1B. One end of resistor R4 is connected to the positive terminal of the auxiliary power source, and the other end is connected to the inverting terminal of operational amplifier N1B. The inverting terminal of operational amplifier N1B is also connected to one end of resistor R5 and one end of capacitor C2. The other end of capacitor C2 is connected to the negative terminal of the input power supply. The other end of resistor R5 is connected to one end of thermistor RT, and the other end of thermistor RT is connected to the negative terminal of the input power supply. One end of resistor R6 is connected to one end of resistor R7, and the connection end of resistors R6 and R7 is simultaneously connected to the non-inverting terminal of integrated circuit N1B. The other end of resistor R6 is connected to the ground of the input power supply, and the other end of resistor R7 is connected to the output terminal of operational amplifier N1B.

4. A highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 3, wherein: The thermistor RT is a negative temperature coefficient resistor, and the lower the temperature, the greater the resistance.

5. The high-reliability heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 3, characterized in that: The automatic heating circuit consists of a triode V1, a MOS transistor Q1, resistors R8, R9, R10, R11, R12, R13, R14, R15, an operational amplifier N1A, and a heating element. The output terminal of the operational amplifier N1B is connected to one end of the resistor R8. The other end of R8 is connected to the resistor R9. The connected end of the resistors R8 and R9 is connected to the non-inverting terminal of the operational amplifier N1A and one end of the resistor R12. The other end of the resistor R12 is connected to the output terminal of the operational amplifier N1A. One end of the resistor R10 is connected to one end of the resistor R11. The connected end of the resistors R10 and R11 is connected to the inverting terminal of the operational amplifier N1A. The other end of the resistor R10 is connected to the positive terminal of the auxiliary source. The other end of the resistor R11 is connected to the ground of the input power supply. The output terminal of the operational amplifier N1A is connected to one end of the resistor R13. The other end of the resistor R13 is connected to one end of the resistor R14 and the base of the triode V1. The other end of the resistor R14 is connected to the ground of the input power supply. The emitter of the triode V1 is connected to the ground of the input power supply. The source of the triode V1 is connected to one end of the resistor R15. The other end of the resistor R15 is connected to the gate of the MOS transistor Q1. The source of the MOS transistor Q1 is connected to the positive terminal of the input power supply. The drain of the MOS transistor Q1 is connected to one end of the heating element. The other end of the heating element is connected to the current sampling circuit. The resistors R10 and R11 set the low-temperature voltage threshold. When the sampled temperature voltage is higher than the threshold value, the operational amplifier N1A outputs a high level, the triode V1 conducts, the MOS transistor Q1 conducts, and the heating element works.

6. The highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 5, wherein: The automatic cooling circuit consists of a MOS transistor Q2, resistors R16, R17, R18, R19, R20, R21, R22, an operational amplifier N1C, and a fan. The output terminal of the operational amplifier N1B is connected to one end of the resistor R20. The other end of R20 is connected to the resistor R17. The connected end of the resistors R20 and R17 is connected to the inverting terminal of the operational amplifier N1C. The other end of the resistor R17 is connected to the ground of the input power supply. One end of the resistor R16 is connected to one end of the resistor R18. The connected end of the resistors R16 and R18 is connected to the non-inverting terminal of the operational amplifier N1C and one end of the resistor R19. The other end of the resistor R16 is connected to the positive terminal of the auxiliary source. The other end of the resistor R18 is connected to the ground of the input power supply. The other end of the resistor R19 is connected to the output terminal of the operational amplifier N1C. The output terminal of the operational amplifier N1C is connected to one end of the resistor R21. The other end of the resistor R21 is connected to one end of the resistor R22 and the gate of the MOS transistor Q2. The other end of the resistor R22 is connected to the source of Q2. The source of the MOS transistor Q2 is connected to the current sampling circuit. The drain of the MOS transistor Q2 is connected to the negative terminal of the fan. The positive terminal of the fan is connected to the positive terminal of the input power supply. The resistors R16 and R18 set the high-temperature voltage threshold. When the sampled temperature voltage is lower than the threshold value, the operational amplifier N1C outputs a high level, the MOS transistor Q2 conducts, and the fan works.

7. The highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 6, characterized in that: The current sampling circuit consists of resistors R23, R24, R25, R26, sampling resistor R0, and operational amplifier N1D. One end of the sampling resistor R0 is connected to the forced shutdown circuit, and the other end is connected to one end of resistor R23, the source of MOS transistor Q2, and one end of the heating element. The other end of resistor R23 is connected to one end of resistor R25. The connection point of resistor R23 and R25 is connected to the non-inverting input terminal of operational amplifier N1D. The other end of resistor R25 is connected to the ground of the output power supply. The connection point of resistor R24 and R26 is connected to the inverting input terminal of operational amplifier N1D. The other end of resistor R26 is connected to the ground of the input power supply. The other end of resistor R26 is connected to the output terminal of operational amplifier N1D. The sampling resistor R0 samples the current, and the operational amplifier N1D and resistors R23, R24, R25, R26 form a differential amplifier circuit to amplify the voltage signal on R0 and report the current value to the upper-level system in real time.

8. The highly reliable heating / dissipating heat automatic switching high-efficiency power supply circuit according to claim 6, wherein: The forced shutdown circuit consists of transistor V2, MOS transistor Q3, and resistors R27, R28, R29, R30. The positive terminal of the input power supply is connected to one end of resistor R29. The other end of resistor R29 is connected to the collector of transistor V2, the gate of MOS transistor Q3, and one end of resistor R30. The other end of resistor R30 is connected to the emitter of transistor V2, the source of MOS transistor Q3, and is connected to the ground of the input power supply. The drain of MOS transistor Q3 is connected to the sampling resistor R0. The connection point of resistor R27 and R28 is connected to the base of transistor V2. The other end of resistor R28 is connected to the ground of the input power supply. The forced shutdown signal is input from the other end of resistor R27. During normal operation, transistor V2 is not conducting, and the voltage division of resistors R29 and R30 ensures that MOS transistor Q2 is conducting. When the upper-level system needs to force a shutdown, a high-level signal is input from one end of resistor R27, transistor V2 conducts, the gate voltage of MOS transistor Q3 is pulled low, MOS transistor Q3 turns off, and the automatic heating or cooling circuit is turned off.

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