Title:
CIRCUIT FOR REALIZING ZVS OF FLYBACK SWITCHING POWER SUPPLY BY USING AUXILIARY WINDING
Document Type and Number:
WIPO Patent Application WO/2024/066495
Kind Code:
A1
Abstract:
A circuit for realizing a ZVS of a Flyback switching power supply by using an auxiliary winding, relating to the field of switching power supplies. On the basis of an original auxiliary winding of a transformer, a ZVS capacitor and a ZVS switch module are added, one end of the ZVS capacitor and a non-dotted end of the auxiliary winding are connected to a first node, and before a primary side power switch is turned on, a control circuit generates a ZVS control signal according to a first node voltage to turn on the ZVS switch module, so that a resonance current is formed between the auxiliary winding, the ZVS capacitor and the ZVS switch module, so as to cause the voltage of the primary side power switch to generate resonance downward. Moreover, the magnetic coupling between the auxiliary winding and the transformer realizes a reverse excitation current of a primary side winding, to extract the junction capacitance charge of the primary side power switch, so that the Vds voltage of the primary side power switch is reduced to zero, and ZVS of the primary side power switch is realized, thereby improving the working efficiency of a Flyback power supply system.
Inventors:
YING ZHENG (CN)
WANG FENG (CN)
CHEN BO (CN)
WANG FENG (CN)
CHEN BO (CN)
Application Number:
PCT/CN2023/100617
Publication Date:
April 04, 2024
Filing Date:
June 16, 2023
Export Citation:
Assignee:
BCD SHANGHAI MICRO ELECTRONICS COMPANY LTD (CN)
International Classes:
H02M3/28; H02M3/335
Foreign References:
| CN115514233A | 2022-12-23 | |||
| CN218633713U | 2023-03-14 | |||
| CN115498883A | 2022-12-20 | |||
| CN111917301A | 2020-11-10 | |||
| CN209562410U | 2019-10-29 | |||
| CN108539986A | 2018-09-14 | |||
| CN102386779A | 2012-03-21 | |||
| US20220038020A1 | 2022-02-03 |
Attorney, Agent or Firm:
UNITALEN ATTORNEYS AT LAW CO., LTD. (CN)
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