Voltage conversion circuit for vehicle air conditioner

Abstract

The utility model relates to a voltage conversion circuit for a vehicle air conditioner. The voltage conversion circuit comprises an input power supply, a filter circuit, a power supply management chip, a transformer, an output circuit and an output detection feedback circuit. The filter circuit is composed of a first inductor and a first capacitor. And the power management chip realizes voltage conversion by controlling the working state of the transformer, and is connected with the three independent output circuits to respectively meet different voltage output requirements. And the output circuit comprises a plurality of voltage stabilizing modules to ensure that each output voltage is stable and reliable. In order to accurately adjust the output voltage and current, the circuit is provided with two output detection feedback circuits, the output voltage and current information is transmitted to a power management chip in real time through an optocoupler feedback mechanism, and stable output of the power supply is ensured. The voltage conversion circuit has the advantages of high efficiency, low energy consumption, strong anti-interference capability and multi-path voltage stabilization output, can stably operate in a complex electromagnetic environment, and is suitable for power supply management of high-power consumption equipment such as a vehicle air conditioner.

Description

TECHNICAL FIELD

[0001] The utility model belongs to power conversion technical field, concretely relates to a voltage conversion circuit for vehicle air conditioner. BACKGROUND

[0002] The urban rail transit vehicle air conditioner ventilation system includes an FPC20 control panel, which mainly functions to collect vehicle temperature, humidity, dust concentration and air flow speed and the like parameters, and after the information collected by the sensor is processed, the information is forwarded to the main control unit of the train information management system, the FPC20 air conditioner control panel is composed of two circuit boards, including a power board and a CPU board, and the boards are connected by pins to form the whole module, and it is found in the actual maintenance process that the FPC20 fault of the vehicle air conditioner mainly occurs in the power board part, the power board cannot normally supply power, and the whole carriage air conditioner is damaged.

[0003] The existing vehicle air conditioner voltage conversion circuit has the following problems and defects: 1. Lack of effective regulation of output voltage and current, easy to cause equipment damage or performance decline due to voltage fluctuation; 2. Complex circuit design, low efficiency, not suitable for high-power vehicle air conditioning system; 3. Lack of voltage stabilizing measures and anti-interference processing, easy to be affected by vehicle electromagnetic interference, reduce the stability and reliability of the system. UTILITY MODEL CONTENTS

[0004] The utility model aims at overcoming the defects of the prior art and provides a voltage conversion circuit for vehicle air conditioner.

[0005] The utility model can achieve the purpose by the following technical scheme:

[0006] The utility model provides a voltage conversion circuit for vehicle air conditioner, including input power, filter circuit, power management chip, transformer, output circuit, output detection feedback circuit, filter circuit includes first capacitor and common mode inductor, output detection feedback circuit includes first output detection feedback circuit, second output detection feedback circuit and error amplifier, first output detection feedback circuit includes first opto-coupler and second diode, second output detection feedback circuit includes second opto-coupler, input power is connected with first capacitor, and first capacitor is connected with the pin of common mode inductor respectively 1, 4, the pin of common mode inductor 3 is connected with the pin of transformer 1, and the pin of transformer 2 is connected with the pin of power management chip 7, and the secondary winding of transformer is connected with the input end of output circuit, and the output end of output circuit is connected with the input end of output detection feedback circuit, and the pin 3 of first opto-coupler, the pin 3 of second opto-coupler and the pin 1 of power management chip are connected.

[0007] Further, the power management chip is a TOP247YN chip.

[0008] Further, the output circuit comprises a first output circuit, a second output circuit and a third output circuit.

[0009] Further, the first output circuit comprises a rectifier diode, a first inductor, a second capacitor and a first diode connected in sequence.

[0010] Further, the second output circuit comprises a third diode and a first voltage stabilizer connected in sequence.

[0011] Further, the third diode of the second output circuit is connected with the 7th pin of the secondary winding of the transformer, the cathode of the third diode is connected with the input end of the first voltage stabilizer, and the output end of the first voltage stabilizer of the second output circuit is connected with the 1st pin of the first optocoupler and the 1st pin of the second optocoupler.

[0012] Further, the third output circuit comprises a fourth diode and a second voltage stabilizer connected in sequence.

[0013] Further, the fourth diode of the third output circuit is connected with the 5th pin of the secondary winding of the transformer, the anode of the fourth diode is connected with the input end of the second voltage stabilizer, and the output end of the second voltage stabilizer of the third output circuit is connected with the 1st pin of the first optocoupler and the 1st pin of the second optocoupler.

[0014] Further, the 4th pin of the transformer is connected with the 4th pin of the first optocoupler and the 4th pin of the second optocoupler.

[0015] Further, the 2nd pin of the second output detection feedback circuit is connected with the input end of the error amplifier, the anode of the second diode of the first output detection feedback circuit is connected with the output end of the output circuit, and the cathode of the second diode is connected with the 2nd pin of the first optocoupler.

[0016] Compared with the prior art, the power supply management chip has the following advantages:

[0017] (1) The first output detection feedback circuit and the second output detection feedback circuit are introduced, so that the output voltage and current are fed back to the power supply management chip in real time, the accurate adjustment of the output voltage and current in the voltage conversion process is ensured, and the device damage and performance instability caused by voltage fluctuation are avoided.

[0018] (2) The power supply management chip adopts the TOP247YN chip, and the power supply management chip plays a core role in the circuit, the working state of the transformer is reasonably controlled, the conversion efficiency of the power supply is optimized, the energy loss is reduced, and the overall energy efficiency of the system is improved.

[0019] (3) The utility model discloses three independent output circuits, which are used for different voltage level output requirements respectively, to ensure that the system can meet the various working modes of the vehicle air conditioner, and through the voltage stabilizing design of the second and third output circuits, the stability of the output voltage and the load adaptability are improved.

[0020] (4) The utility model discloses multistage filter circuit and opto -coupler feedback mechanism are adopted, effectively reduce the electromagnetic interference that produces in voltage conversion process, improve the anti -interference ability of system, ensure that the reliable operation of air conditioning system under complex environment.

[0021] (5) The circuit design of the utility model through reasonable layout each module, especially in the configuration of output circuit and feedback circuit, both ensure the good cooperation between each circuit, and simplify the overall circuit structure, help to reduce the cost and optimize installation and maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the circuit structure diagram of the utility model;

[0023] Figure 2 It is the circuit schematic diagram of the utility model;

[0024] The reference sign in the drawing is: C0, first capacitor, L1, common mode inductance, T1, transformer, U1, power control chip, D4, rectifier diode, L2, first inductance, C5, second capacitor, D8, first diode, U2, first opto -coupler, U3, second opto -coupler, D7, second diode, U6, error amplifier, U4, first voltage stabilizer, U5, second voltage stabilizer, D5, third diode, D6, fourth diode. DETAILED DESCRIPTION

[0025] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model, obviously, the described embodiments are a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor should belong to the protection scope of the utility model.

[0026] The embodiment provides a voltage conversion circuit for a vehicle air conditioning system, which is designed to solve the problems of unstable output voltage, low efficiency and poor anti-interference ability in existing circuits. The circuit can provide stable voltage output, ensure the normal operation of the vehicle air conditioning system in various working environments, and improve the stability and reliability of the system.

[0027] The voltage conversion circuit described in this embodiment includes an input power supply, a filter circuit, a power management chip, a transformer, an output circuit, and an output detection feedback circuit. Each module is connected and cooperates reasonably to achieve efficient voltage conversion, stable power output, and precise current control.

[0028] In specific implementation, the input power supply provides a direct current power supply for the vehicle battery or electrical system, usually 24V DC. The input power supply is first processed by the filter circuit. The filter circuit includes a first capacitor and a common mode inductor, wherein one port of the first capacitor is connected to the input power supply, and the other end is connected to pin 1 and pin 4 of the common mode inductor respectively. The common mode inductor can effectively filter out high-frequency noise and voltage fluctuations in the power supply through its specific structure and design, ensuring the smoothness and stability of the power supply input. Through this filtering process, the high-frequency noise and pulses in the input power supply are greatly suppressed, thereby reducing the influence of electromagnetic interference on other parts of the circuit.

[0029] Next, the filtered power supply signal is sent to the power management chip. The power management chip (such as TOP247YN chip) is used to control the voltage conversion process, adjust the output voltage, and perform feedback adjustment. The pin 7 of the chip is connected to the pin 2 of the transformer, forming a control loop for voltage conversion. The power management chip not only adjusts the voltage, but also monitors the output current in real time to ensure that the output voltage is always within the set range, thereby preventing damage to air conditioning equipment caused by excessive voltage fluctuations.

[0030] The transformer, as the core component of voltage conversion, receives the input power supply controlled by the power management chip and converts it into high-frequency alternating voltage suitable for output. The primary winding pin 1 of the transformer is connected to the input power supply through the common mode inductor pin 3, while the secondary winding of the transformer is connected to multiple output circuits through its pins. The transformer converts and isolates the input signal to provide multiple output voltages of different levels to meet the voltage requirements of different parts of the vehicle air conditioning system.

[0031] The voltage conversion circuit of this embodiment includes three output circuits: the first output circuit, the second output circuit, and the third output circuit. Each output circuit is composed of rectifier diodes, filter inductors, capacitors, voltage stabilizers, and diodes, etc. for further rectification, filtering, and voltage stabilization of the voltage.

[0032] The first output circuit is composed of a rectifier diode, a first inductor, a second capacitor and a first diode. The rectifier diode is connected to the secondary winding pin 10 of the transformer, responsible for rectifying the alternating voltage output by the transformer into direct current voltage. The rectified current first passes through the first inductor, then through the second capacitor for smoothing filtering, and finally through the first diode to output stable direct current voltage. The first optocoupler and the second optocoupler are respectively connected to the feedback pin of the output circuit, used for real-time monitoring of the output voltage, and transmitting the feedback signal to the power management chip, so as to adjust the output voltage and ensure its stability.

[0033] The second output circuit is composed of a third diode and a first voltage regulator. The anode of the third diode is connected to the secondary winding pin 7 of the transformer, and the cathode is connected to the input end of the first voltage regulator. The voltage regulator further adjusts the voltage to a predetermined value, and the output after voltage stabilization is fed back to the power management chip through the optocoupler, used for adjusting the output voltage. The second optocoupler is used to transmit the feedback signal of the output voltage to the error amplifier, for further accurate control of the output voltage.

[0034] The third output circuit is composed of a fourth diode and a second voltage regulator. The cathode of the fourth diode is connected to the secondary winding pin 5 of the transformer, and the anode is connected to the input end of the second voltage regulator. The voltage after voltage stabilization is output and fed back to the power management chip through the optocoupler, to adjust the voltage stability.

[0035] The first optocoupler, the second optocoupler, the third optocoupler and other elements in the output circuit adjust the output voltage through feedback control. The function of the feedback loop is to dynamically adjust the output voltage according to the working state of the circuit, to ensure that it is always within the predetermined range, and will not cause voltage instability due to load changes or input power fluctuations.

[0036] The entire voltage conversion circuit is controlled in stability and accuracy by the output detection feedback circuit. The first output detection feedback circuit includes a first optocoupler and a second diode, wherein the anode of the second diode is connected to the output voltage end, and the cathode is connected to pin 2 of the first optocoupler. The feedback signal is transmitted through the optocoupler, to adjust the output voltage. When the output voltage reaches the set value, the feedback signal is transmitted to the power management chip, to adjust the working state of the chip and ensure the stability of the voltage output. The second output detection feedback circuit includes a second optocoupler, and the feedback signal is connected to the error amplifier through the pin of the second optocoupler, to further adjust the output voltage.

[0037] An error amplifier receives and amplifies the feedback signal. The amplified feedback signal, in collaboration with other circuits and the power management chip, further regulates the voltage output, ensuring it remains within a stable operating range. Pins 3 of the first and second optocouplers are connected to pin 1 of the power management chip. Through the working principle of the optocouplers, the voltage feedback signal is effectively transmitted to the power management chip, thereby regulating the voltage output and achieving precise control.

[0038] The working principle of this embodiment:

[0039] like Figure 1 As shown, this circuit mainly includes an input power supply, a filter circuit, a power management chip, a transformer, an output circuit, and an output detection feedback circuit connected in sequence. The specific structure of each circuit is as follows: Figure 2 As shown, the input power supply is DC 110V. The input power supply is connected to the first capacitor C0. The first capacitor C0 is connected to pins 1 and 4 of the common mode inductor L1. The DC power supply signal filtered by the common mode inductor is output to the transformer through pin 3 of the common mode inductor L1. The transformer outputs filtered DC 5.1V 2.5A, DC 15V 0.3A and DC -15V 0.3A through pins 10, 7 and 5 of the secondary winding, respectively. Specifically, pin 10 of the transformer is connected to the first output circuit, which includes a rectifier diode D4, a first inductor L2, a second capacitor C5, and a first diode D8 connected in sequence. The input terminal of the rectifier diode D4 is connected to pin 10 of the transformer's secondary winding. The cathode of the first diode D8 is connected to pin 1 of the first optocoupler and pin 1 of the second optocoupler, respectively. Through rectification by the rectifier diode D4 and filtering by the first inductor L2, the second capacitor C5, and the first diode D8, a DC 5.1V 2.5A filter is output. Pin 7 of the transformer is connected to the third diode D5 of the second output circuit, and then connected to the first voltage regulator U4. Through the output terminal of the first voltage regulator U4, a DC 15V 0.3A filter is output. Pin 10 of the transformer is connected to the fourth diode D6 of the third output circuit, and then connected to the second voltage regulator U5. Through the output terminal of the second voltage regulator U5, a DC -15V 0.3A filter is output. Then, the output terminals of the first, second, and third output circuits are connected to pin 1 of the first optocoupler U2 and the second optocoupler U3, respectively. The optocouplers play a crucial role in signal isolation and feedback control, feeding the output signal back to pin 1 of the power control chip. Pin 2 of the transformer is connected to pin 7 of the power control chip (TOP247YN). The signal received at pin 7 is transmitted to pin 4 through the MOSFET. Pin 4 is connected to pin 2 of the common-mode inductor, forming a loop. The power control chip adjusts the duty cycle in real time based on the output signal received at pin 1, thereby regulating the voltage between pins 1 and 2 of the transformer and thus adjusting the output voltage and current.

[0040] During the regulation process of the power supply control chip, all signal transmission and feedback control are achieved through precise pin connections. The input power is a DC 110V voltage, which is connected with a common mode inductor L1 through a first capacitor C0. The 1 and 4 pins of L1 form a filter circuit with C0, removing high-frequency noise and electromagnetic interference in the input power supply to ensure the stability of the DC power signal output to the transformer. The 3 pin of the common mode inductor L1 outputs the filtered power signal to the primary winding of the transformer.

[0041] After receiving the filtered DC power signal, the transformer converts the voltage into multiple different output voltages according to its design. The secondary winding of the transformer outputs three different voltages through the 10 pin, 7 pin, and 5 pin, respectively. The 10 pin is connected to the first output circuit, outputting DC 5.1V 2.5A; the 7 pin is connected to the second output circuit, outputting DC 15V 0.3A; and the 5 pin is connected to the third output circuit, outputting DC -15V 0.3A. Each output circuit ensures the stability of the output voltage through rectification, filtering, and voltage stabilizing elements. For example, the first output circuit is composed of rectifier diode D4, first inductor L2, second capacitor C5, and first diode D8, etc., to rectify and filter the voltage signal output by the transformer 10 pin, providing a stable DC 5.1V 2.5A voltage. The second output circuit stabilizes the signal output by the 7 pin through the third diode D5 and the first voltage stabilizer U4, providing a DC 15V 0.3A output; the third output circuit stabilizes the signal output by the 5 pin through the fourth diode D6 and the second voltage stabilizer U5, obtaining a DC -15V 0.3A output.

[0042] To ensure the stability of the output voltage, the power supply control chip needs to receive the feedback signal of the output voltage. The output end of each output circuit is connected to the 1 pin of the power supply control chip through the 1 pin of the optocoupler U2 and U3, respectively. The optocoupler here plays the role of signal isolation and feedback, transmitting the output voltage information to the power supply control chip while avoiding interference from high voltage parts to low voltage control parts. The optocoupler converts the information of each output voltage into an electrical signal and feeds it back to the power management chip, allowing the chip to obtain real-time output voltage change data.

[0043] After receiving the feedback signal from the optocoupler, the power management chip (such as TOP247YN) compares the feedback signal with the reference voltage using the built-in error amplifier. The output signal of the error amplifier adjusts the internal PWM controller, which controls the switching state of the MOSFET to adjust the voltage conversion process. The MOSFET controls the current on the primary side of the transformer. When the MOSFET is on, the current passes through the primary winding of the transformer, and the transformer converts the input voltage to the output voltage of the secondary winding; when the MOSFET is off, the current stops, and the output voltage is adjusted.

[0044] The PWM controller dynamically adjusts the duty cycle of the MOSFET, i.e. the ratio of on-time to off-time, based on the feedback signal, ensuring that the output voltage remains stable. When the output voltage is too high, the power management chip reduces the on-time of the MOSFET to lower the output voltage; when the output voltage is too low, it increases the on-time to increase the output voltage. The 7-pin of the power management chip is connected to the 2-pin of the transformer, used to receive voltage signals from the primary side of the transformer. Through these signals, the power management chip can monitor the input voltage in real time and adjust the working state of the MOSFET according to the feedback.

[0045] When the feedback signal reaches the 1-pin of the power management chip, the chip controls the switching of the MOSFET through the 4-pin. The 4-pin is connected to the 2-pin of the common-mode inductor L1, forming a closed loop that allows the power management chip to adjust the duty cycle of the PWM controller based on the feedback signal, thereby adjusting the operating frequency of the transformer and controlling the output voltage. The entire process is controlled by precise feedback control and dynamic adjustment, ensuring that each output voltage is stable within the required range, meeting the system's power requirements.

[0046] Through this feedback control mechanism, the power management chip can accurately adjust the switching state of the MOSFET based on real-time feedback signals, control the working state of the transformer, and thus ensure the stability and adaptability of the output voltage. This allows the power control circuit to adapt to changes in load and provide stable voltage output in high-power devices such as vehicle air conditioners.

[0047] Furthermore, the first output detection feedback circuit of the utility model is provided with the second diode D7, be used for preventing overvoltage or reverse current in feedback circuit. The connection of the optocoupler and the diode D7 is to protect the feedback loop and avoid damage to the power management chip and other low-voltage control parts caused by high voltage or reverse current.

[0048] The purpose of setting two optocouplers is to achieve efficient signal isolation and feedback control. One optocoupler is connected to the diode D7, providing overvoltage or reverse current protection to ensure the stability and safety of the feedback loop; the other optocoupler is connected to the error amplifier, providing accurate feedback signals to help the power management chip make dynamic adjustments. Through the cooperation of the two optocouplers, the power supply circuit can monitor the output voltage in real time and ensure stable and reliable operation of the power supply.

[0049] And through the redundant setting of two optocouplers, even if one optocoupler is damaged, it will not affect the use of the entire circuit.

[0050] The embodiment ensures the high efficiency, stability and anti-interference ability of the voltage conversion circuit by using the light coupling feedback technology, the error amplifier and the voltage stabilizer in combination. The circuit can monitor and adjust the output voltage in real time, avoids the influence of voltage fluctuation on the vehicle air conditioning system, especially in the high-power vehicle air conditioning system, and provides reliable power supply guarantee. Meanwhile, the circuit structure is simple, the component selection is reasonable, the power conversion efficiency can be effectively improved, and the energy loss can be reduced, and it is a kind of efficient, stable and reliable voltage conversion solution.

[0051] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any skilled person in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A voltage conversion circuit for vehicle air conditioning, characterized in that, The circuit includes an input power supply, a filter circuit, a power management chip, a transformer, an output circuit, and an output detection feedback circuit. The filter circuit includes a first capacitor and a common-mode inductor. The output detection feedback circuit includes a first output detection feedback circuit, a second output detection feedback circuit, and an error amplifier. The first output detection feedback circuit includes a first optocoupler and a second diode. The second output detection feedback circuit includes a second optocoupler. The input power supply is connected to the first capacitor. The first capacitor is connected to pins 1 and 4 of the common-mode inductor. Pin 3 of the common-mode inductor is connected to pin 1 of the transformer. Pin 2 of the transformer is connected to pin 7 of the power management chip. The secondary winding of the transformer is connected to the input terminal of the output circuit. The output terminal of the output circuit is connected to the input terminal of the output detection feedback circuit. Pins 3 of the first optocoupler and pin 3 of the second optocoupler are connected to pin 1 of the power management chip.

2. The voltage conversion circuit for a vehicle air conditioner according to claim 1, characterized in that, The power management chip is the TOP247YN chip.

3. The voltage conversion circuit for a vehicle air conditioner according to claim 1, characterized in that, The output circuit includes a first output circuit, a second output circuit, and a third output circuit.

4. A voltage conversion circuit for a vehicle air conditioner according to claim 3, characterized in that, The first output circuit includes a rectifier diode, a first inductor, a second capacitor, and a first diode connected in sequence. The input terminal of the rectifier diode is connected to pin 10 of the secondary winding of the transformer, and the cathode of the first diode is connected to pin 1 of the first optocoupler and pin 1 of the second optocoupler.

5. A voltage conversion circuit for a vehicle air conditioner according to claim 3, characterized in that, The second output circuit includes a third diode and a first voltage regulator connected in sequence.

6. A voltage conversion circuit for a vehicle air conditioner according to claim 5, characterized in that, The anode of the third diode in the second output circuit is connected to pin 7 of the transformer secondary winding, and the cathode of the third diode is connected to the input terminal of the first voltage regulator. The output terminal of the first voltage regulator in the second output circuit is connected to pin 1 of the first optocoupler and pin 1 of the second optocoupler, respectively.

7. A voltage conversion circuit for a vehicle air conditioner according to claim 3, characterized in that, The third output circuit includes a fourth diode and a second voltage regulator connected in sequence.

8. A voltage conversion circuit for a vehicle air conditioner according to claim 7, characterized in that, The cathode of the fourth diode in the third output circuit is connected to pin 5 of the transformer secondary winding, and the anode of the fourth diode is connected to the input terminal of the second voltage regulator. The output terminal of the second voltage regulator in the third output circuit is connected to pin 1 of the first optocoupler and pin 1 of the second optocoupler, respectively.

9. A voltage conversion circuit for a vehicle air conditioner according to claim 1, characterized in that, The transformer's four pins are connected to the first optocoupler's four pins and the second optocoupler's four pins, respectively.

10. A voltage conversion circuit for a vehicle air conditioner according to claim 1, characterized in that, The second optocoupler pin 2 of the second output detection feedback circuit is connected to the input terminal of the error amplifier. The anode of the second diode of the first output detection feedback circuit is connected to the output terminal of the output circuit, and the cathode of the second diode is connected to pin 2 of the first optocoupler.

Images