Patent ID: 11955893
Assignee: SHENZHEN HUNTKEY ELECTRIC CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A switching power supply, comprising a current-mode PWM control unit and a transformer, the current-mode PWM control unit comprising a current detection terminal used for detecting a current in a primary winding of the transformer thereby controlling a power transfer, wherein
the switching power supply further comprises a DC power supply circuit and a power compensation auxiliary circuit connected in series; an input of the DC power supply circuit is connected to an auxiliary voltage output which outputs an auxiliary voltage related to an output voltage of the switching power supply; an output of the power compensation auxiliary circuit is connected to the current detection terminal;
the power compensation auxiliary circuit is used to determine an output voltage of the DC power supply circuit, when the output voltage of the switching power supply is not greater than a threshold voltage, the power compensation auxiliary circuit generates a DC voltage, thereby providing a compensation voltage to the current detection terminal; when the output voltage of the switching power supply is greater than the threshold voltage, the power compensation auxiliary circuit does not generate the DC voltage, thereby not providing the compensation voltage to the current detection terminal;
wherein said threshold voltage is within an output voltage range of the switching power supply.