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

Claim 0:
1. 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 obtain a DC voltage signal actually output by the converter and a preset output DC voltage signal, determine a voltage loop output value of the converter according to the DC voltage signal actually output and the preset output DC voltage signal, and generate a drive signal for the upper bridge switch and a 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;
the control circuit is configured to detect in real time level information of the drive signal for the upper bridge switch, and generate a trigger signal after a preset time elapsed upon detecting that the drive signal for the upper bridge switch is at a low level; the control circuit is configured to output a low-level drive signal to the lower bridge switch in response to the trigger signal to switch off the lower bridge switch, and output a high-level drive signal to the upper bridge switch after a dead time to switch on the upper bridge switch; and
the preset time is determined according to a difference between a positive peak current value and a negative peak current value on the primary side of the transformer, an instantaneous voltage value of the DC output by the converter, and an excitation inductance of the transformer.