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

Claim 1:
2. The switching power supply of claim 1, wherein the transformer further comprises a first auxiliary winding having a first auxiliary voltage output for generating a first auxiliary voltage related to the output voltage, and a second auxiliary winding having a second auxiliary voltage output for generating a second auxiliary voltage related to the output voltage; the first auxiliary voltage is less than the second auxiliary voltage;
the power compensation auxiliary circuit comprises a switch, a comparator and a voltage generation circuit,
the DC power supply circuit comprises a first DC power supply circuit, a second DC power supply circuit, and a third DC power supply circuit; an input of the first DC power supply circuit is connected to the first auxiliary voltage output or to the second auxiliary voltage output; an output of the first DC power supply circuit, the switch, the voltage generation circuit and the current detection terminal are connected in series; an input of the third DC power supply circuit is connected to the first auxiliary voltage output and an output of the third DC power supply circuit is connected to a first input of the comparator; an input of the second DC power supply circuit is connected to the second auxiliary voltage output and an output of the second DC power supply circuit is connected to a second input of the comparator;
the comparator is used to compare an output voltage of the third DC power supply circuit with an output voltage of the second DC power supply circuit; when the output voltage of the switching power supply is not greater than the threshold voltage, the comparator outputs a control signal to control the switch to be on, and the voltage generation circuit generates an output voltage, thus providing the compensation voltage to the current detection terminal; when the output voltage of the switching power supply is greater than the threshold voltage, the comparator outputs a control signal to control the switch to be off, and the voltage generation circuit does not generate the DC voltage, thus not providing the compensation voltage to the current detection terminal.