Patent ID: 8031500

Claim:
A bridgeless active power factor corrector (APFC) with a logic control comprising: a first connecting node, a second connecting node, an output voltage terminal, a reference voltage terminal, a boost inductor, and an output filtering capacitor, wherein the boost inductor is positioned between an external AC voltage source and the two connecting nodes, the output filtering capacitor is connected between the output and the reference voltage terminal; a first boost diode and a second boost diode, wherein anodes of the first and second diode are respectively connected to the first and the second connecting node and cathodes are commonly connected to the output voltage terminal; a first boost transistor module and a second boost transistor module, both comprising a first and a second input terminal as well as a first and a second output terminal, wherein the first output terminals are respectively connected to the first and the second connecting node, the second output terminals are commonly connected to the reference voltage terminal; a high frequency switch controller connected to the second input terminals of the first and the second boost transistor module; a first low frequency switch driver and a second low frequency switch driver respectively connected to the first input terminals of the first and the second boost transistor module; and a first and a second input voltage polarity detector, both connected to the external AC voltage source, for respectively detecting the positive and the negative half period during an alternating period as well as respectively controlling the first and the second low frequency switch driver, in conjunction with the high frequency switch controller to respectively drive the first boost transistor module and the second boost transistor module with a logic control.