Flyback charging circuit based on voltage doubling rectification

Abstract

The utility model relates to the technical field of capacitor energy storage, in particular to a flyback charging circuit based on voltage doubling rectification, which comprises a voltage input module, a starting circuit, a main control unit, a high-frequency transformer, a voltage doubling rectification circuit and a voltage feedback circuit. The starting circuit is electrically connected with the main control unit, the output end of the main control unit is electrically connected with the high-frequency transformer, the high-frequency transformer is electrically connected with the voltage doubling rectifying circuit, and the voltage doubling rectifying circuit is electrically connected with the main control unit through the voltage feedback circuit. A voltage doubling rectification technology is adopted, conversion from low voltage to high voltage is achieved, and multi-path voltage output can be achieved on the premise that parameters of the transformer are not changed.

Description

Technical Field

[0001] The utility model relates to the technical field of capacitor energy storage, in particular to a flyback charging circuit based on voltage doubling rectification. Background Art

[0002] In the field of high-voltage capacitor energy storage, it is necessary to convert a lower DC voltage into a higher DC voltage, and then charge the capacitor to store energy. Most existing technologies for high-voltage boosting use transformers to directly boost the voltage to the required voltage. In this way, the transformer has a large primary and secondary turns ratio, and the transformer is large in size after winding, which is not conducive to miniaturization integration. In addition, the existing boosting technology is limited by the maximum operating voltage of the control unit. The maximum input voltage is generally below 32V, and it is impossible to achieve a higher voltage power supply input. Utility Model Content

[0003] In order to solve the above problems, the utility model provides a flyback charging circuit based on voltage doubling rectification.

[0004] The specific technical solution is as follows:

[0005] A flyback charging circuit based on voltage doubling rectification comprises a voltage input module, a starting circuit, a main control unit, a high-frequency transformer, a voltage doubling rectification circuit and a voltage feedback circuit, wherein the voltage input module is electrically connected to the starting circuit and the high-frequency transformer respectively, the starting circuit is electrically connected to the main control unit, the output end of the main control unit is electrically connected to the high-frequency transformer, the high-frequency transformer is electrically connected to the voltage doubling rectification circuit, and the voltage doubling rectification circuit is electrically connected to the main control unit via the voltage feedback circuit.

[0006] The starting circuit includes a transistor, a first resistor, a second resistor, a seventh zener diode, an eighth zener diode and a double diode; the first resistor and the seventh zener diode are connected in series to ground, and their series node is connected to the transistor base, the transistor emitter is connected to the double diode input end via the second resistor, the transistor collector is electrically connected to the voltage input module, and the double diode output end is grounded via the eighth zener diode.

[0007] The high-frequency transformer comprises a primary winding, a secondary winding and an auxiliary winding. The primary winding and the auxiliary winding are electrically connected to a voltage input module, and the secondary winding is electrically connected to a voltage doubling rectifier circuit.

[0008] In a specific implementation, the auxiliary winding is connected to the voltage source pin of the main control unit via a double diode of the start-up circuit.

[0009] A MOS driving tube is also arranged between the main control unit and the high-frequency transformer.

[0010] The voltage-doubling rectifier circuit is composed of a plurality of voltage-doubling capacitors, a plurality of rectifier diodes and a plurality of inductors connected in series and in parallel.

[0011] In a specific implementation, the voltage input module input voltage range is DC16V~55V power supply.

[0012] In order to ensure the reliability of the output voltage, the voltage feedback circuit includes a voltage acquisition module and a photoelectric coupler, and the voltage acquisition module is electrically connected to the photoelectric coupler.

[0013] The beneficial effect is that the utility model is a flyback charging circuit based on voltage doubling rectification, which realizes the conversion from low voltage to high voltage by adopting voltage doubling rectification technology, and can realize multi-channel voltage output without changing the parameters of the high-frequency transformer. It has the characteristics of wide input voltage range of DC16V~DC55V, small circuit size and large output power, thereby improving the charging efficiency and the compactness of the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a system structure diagram of the flyback charging circuit of the present application;

[0015] Figure 2 To start the circuit diagram;

[0016] Figure 3 This is the voltage doubler rectifier circuit diagram. DETAILED DESCRIPTION

[0017] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0018] See also Figure 1 , this embodiment provides a flyback charging circuit based on voltage doubling rectification, including a voltage input module, a starting circuit, a main control unit, a high-frequency transformer, a voltage doubling rectification circuit and a voltage feedback circuit. Among them, the voltage input module is electrically connected to the starting circuit and the high-frequency transformer respectively, and the voltage input module is used to input direct current with a voltage range of 16V to 55V to provide power for the entire flyback charging circuit. The starting circuit is electrically connected to the main control unit and can provide a working voltage for the main control unit. The output end of the main control unit is electrically connected to the high-frequency transformer, and a MOS driving tube is arranged between the output end of the main control unit and the high-frequency transformer. The main control unit can output a PWM output signal to control the MOS driving tube to be turned on or off, so as to adjust the output voltage of the high-frequency transformer. The output end of the high-frequency transformer is electrically connected to the voltage doubling rectification circuit, and can amplify the voltage generated by electromagnetic induction through the voltage doubling rectification circuit to output a high voltage. Furthermore, in order to monitor the high voltage output by the voltage doubler rectifier circuit, the voltage doubler rectifier circuit is electrically connected to a voltage feedback circuit, which is connected to the input end of the main control unit and can transmit the monitored and collected high voltage signal to the main control unit.

[0019] The high-frequency transformer is a key component for realizing voltage conversion, and includes a primary winding, a secondary winding and an auxiliary winding. The primary winding and the auxiliary winding are connected to a voltage input module, and a high voltage is generated in the secondary winding through electromagnetic induction. The secondary winding is electrically connected to a voltage doubling rectifier circuit; the auxiliary winding is connected to a voltage source pin of a main control unit and can provide power to the main control unit.

[0020] In order to provide the main control unit with a startup voltage and adapt to high voltage input, such as Figure 2 As shown, the startup circuit includes a transistor Q1, a first resistor R1, a second resistor R2, a seventh voltage-stabilizing diode D7, an eighth voltage-stabilizing diode D8 and a dual diode D6. One end of the first resistor R1 is connected to a voltage input module, and the other end thereof is connected in series with the seventh voltage-stabilizing diode D7 and grounded; the voltage input module is connected to the collector of the transistor Q1, the base of the transistor Q1 is connected to the series node of R1 and D7, the emitter of the transistor Q1 is connected to the input pin of the dual diode D6 via the second resistor R2, the input pin of the dual diode D6 is also connected to the auxiliary winding via a rectifier diode, the output end of the dual diode D6 is connected to the main control unit, and is grounded through the eighth voltage-stabilizing diode D8. The startup circuit does not need to be charged by a resistor and capacitor, and can quickly provide a startup voltage to the main control unit. At the same time, the eighth voltage-stabilizing diode D8 is set to avoid the impact caused by the high input voltage, prevent the main control unit from being damaged, and can adapt to the high startup voltage input. The use of the dual diode D6 can be powered by the auxiliary winding of the high-frequency transformer after the main control unit is started.

[0021] In order to achieve multiple voltage outputs of different levels without increasing the number of transformer windings, such as Figure 3 As shown, the voltage doubler rectifier circuit is composed of a plurality of voltage doubler capacitors C1 to C4, a plurality of rectifier diodes D2 to D5 and a plurality of inductors L1 and L2 connected in series and in parallel. The voltage doubler capacitors C1 and C2, the rectifier diodes D2 and D3, and the inductor L1 form a first-stage half-wave voltage doubler rectifier circuit. In the negative half cycle of the secondary winding, that is, the 5th pin of the secondary winding is the positive pole and the 8th pin is the negative pole, the rectifier diode D2, the inductor L1 and the voltage doubler capacitor C1 are connected in series, and D2 is turned on to charge the voltage doubler capacitor C1. The voltage value of the voltage doubler capacitor C1 is The output voltage of the secondary winding; when the secondary winding is in the positive half cycle, the rectifier diode D2 is cut off, the voltage doubling capacitor C1, the rectifier diode D3, and the voltage doubling capacitor C3 are connected in series, the rectifier diode D3 is turned on, the secondary winding and the voltage doubling capacitor C1 charge the voltage doubling capacitor C3, and the voltage value of C3 is twice the output voltage of the secondary winding. Similarly, the voltage doubling capacitors C3, C4, rectifier diodes D4, D5 and inductor L2 form a second-stage half-wave voltage doubling rectifier circuit, and the first half-wave voltage doubling rectifier circuit is connected in series with the second half-wave voltage doubling rectifier circuit.

[0022] When the rectifier diode is turned on according to the current direction of the secondary winding of the high-frequency transformer, it charges and stores energy for the voltage-doubling capacitor; when the current direction of the secondary winding is cut off, the secondary winding and the stored energy stored in the voltage-doubling capacitor are superimposed and amplified, and a high voltage output is achieved through a plurality of voltage-doubling capacitors connected in series. At the same time, the multiplier rectifier circuit is provided with a plurality of inductors, which can buffer when the current changes, and can store energy when the MOS drive tube is turned on, and release energy to output current to the load when the MOS drive rod is turned off, thereby improving the output capacity of the voltage-doubling rectifier circuit.

[0023] In order to ensure the reliability of the output voltage, the voltage feedback circuit includes a voltage acquisition module and a photoelectric coupler. The voltage acquisition module is electrically connected to the photoelectric coupler. The voltage acquisition module can sample the voltage at the output end of the voltage doubler rectifier circuit, and isolate the collected voltage signal through the photoelectric coupler and feed it back to the main control unit. The main control unit adjusts the duty cycle of the PWM output signal according to the feedback signal of the voltage feedback circuit, thereby monitoring the output voltage in real time and ensuring the stability of the output voltage.

[0024] After the power supply of the flyback charging circuit is turned on, the input voltage of the voltage input module provides the starting voltage to the main control unit through the starting circuit. After the control unit is powered on, it outputs a PWM output signal to control the conduction and cutoff of the MOS driving tube. When the MOS driving tube is turned on, the electric energy input by the voltage input module is stored in the high-frequency transformer. When the MOS tube is turned off, the electric energy stored in the high-frequency transformer is released through the secondary winding and input into the voltage doubler rectifier circuit. After the voltage doubler rectifier, a high voltage is generated to supply power to the load.

Claims

1. A flyback charging circuit based on voltage doubling rectification, characterized in that: It includes a voltage input module, a starting circuit, a main control unit, a high-frequency transformer, a voltage doubler rectifier circuit and a voltage feedback circuit. The voltage input module is electrically connected to the starting circuit and the high-frequency transformer respectively, the starting circuit is electrically connected to the main control unit, the output end of the main control unit is electrically connected to the high-frequency transformer, the high-frequency transformer is electrically connected to the voltage doubler rectifier circuit, and the voltage doubler rectifier circuit is electrically connected to the main control unit via the voltage feedback circuit.

2. The flyback charging circuit according to claim 1, characterized in that: The starting circuit includes a transistor, a first resistor, a second resistor, a seventh zener diode, an eighth zener diode and a double diode; the first resistor and the seventh zener diode are connected in series to ground, and their series node is connected to the transistor base, the transistor emitter is connected to the double diode input end via the second resistor, the transistor collector is electrically connected to the voltage input module, and the double diode output end is grounded via the eighth zener diode.

3. The flyback charging circuit according to claim 2, characterized in that: The high-frequency transformer comprises a primary winding, a secondary winding and an auxiliary winding. The primary winding and the auxiliary winding are electrically connected to a voltage input module, and the secondary winding is electrically connected to a voltage doubling rectifier circuit.

4. The flyback charging circuit according to claim 3, characterized in that: The auxiliary winding is connected to the voltage source pin of the main control unit via the double diodes of the starting circuit.

5. The flyback charging circuit according to claim 1, characterized in that: A MOS driving tube is also arranged between the main control unit and the high-frequency transformer.

6. The flyback charging circuit according to claim 1, characterized in that: The voltage-doubling rectifier circuit is composed of a plurality of voltage-doubling capacitors, a plurality of rectifier diodes and a plurality of inductors connected in series and in parallel.

7. The flyback charging circuit according to claim 1, characterized in that: The voltage input module input voltage range is DC16V~55V power supply.

8. The flyback charging circuit according to claim 1, characterized in that: The voltage feedback circuit comprises a voltage acquisition module and a photoelectric coupler, and the voltage acquisition module is electrically connected to the photoelectric coupler.

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