Patent ID: 11870354
Assignee: MERAKI INTEGRATED CIRCUIT (SHENZHEN) TECHNOLOGY, LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 8:
9. A control method for an asymmetric half-bridge flyback circuit-based converter, wherein the converter is configured to convert an alternating current (AC) input at an AC input end into a direct current (DC) within a preset voltage value range, the converter comprising: a full-bridge rectifier circuit, a half-bridge circuit, a resonant circuit, a transformer, a load output circuit, and a control circuit; wherein
the full-bridge rectifier circuit is configured to perform full-bridge rectification on the AC input at the AC input end to obtain a unidirectional pulsating DC and output the unidirectional pulsating DC to the half-bridge circuit;
the half-bridge circuit comprises an upper bridge switch and a lower bridge switch, and the half-bridge circuit is configured to convert alternately, by switching on the upper bridge switch and the lower bridge switch alternately, the unidirectional pulsating DC into an AC having a voltage amplitude changing with a waveform of an AC voltage input at the AC input end and outputting the AC to a primary side of the transformer;
the resonant circuit is configured to perform auxiliary communication on the primary side of the transformer;
the transformer is configured to convert the AC on the primary side of the transformer into an AC having a preset voltage value on a secondary side;
the load output circuit is configured to convert the AC having the preset voltage value on the secondary side of the transformer into a DC and output the DC;
the control circuit is configured to generate a drive signal for the upper bridge switch and a drive signal for the lower bridge switch of the half-bridge circuit, and outputs the drive signals to the upper bridge switch and the lower bridge switch to control the upper bridge switch and the lower bridge switch to be switched on alternately;
wherein the control method comprises:
obtaining a DC voltage signal actually output by the converter and a preset output DC voltage signal;
determining a voltage loop output value of the converter according to the DC voltage signal actually output and the preset output DC voltage signal;
generating the drive signal for the upper bridge switch and the drive signal for the lower bridge switch of the half-bridge circuit according to the voltage loop output value of the converter, an instantaneous voltage value of the AC input at the AC input end, an instantaneous current value of a current signal on the primary side of the transformer, to make the current signal on the primary side of the transformer change according to a regularity of the AC voltage signal input at the AC input end, wherein the upper bridge switch and the lower bridge switch are configured to be switched on alternately;
detecting in real time level information of the drive signal for the upper bridge switch; and
generating a trigger signal after a preset time elapsed upon detecting that the drive signal of the upper bridge switch is at a low level, outputting a low-level drive signal to the lower bridge switch in response to the trigger signal to switch off the lower bridge switch, and outputting a high-level drive signal to the upper bridge switch to switch on the upper bridge switch.