AC current detector and power supply circuit.

摘要

An full bridge Zero-Voltage-Switched DC/DC converter with the four MOSFET switches feeding the primary winding of the output transformer (T1) through a series inductance and a series DC blocking capacitance uses two MOSFET asynchronous rectifiers (Q2) in its full wave output section. Each is serially connected between the output transformer and the output shunt capacitance (C') through the primary winding (T21) of a transformer detecting its drain current. The secondary winding (T22) of the detector transformer is shunted by a pair of resistances (R1/R'1) each in series with the base-emitter junction of a bipolar transistor (Q1/Q'1), the two transistors of complementary polarity forming a totem-pole branched across an auxiliary winding (T12) of the output transformer. The totem-pole output coupled (R2) to the gate of the MOSFET switches its state upon the drain current current value crossing the adjustable (R1/R'1) low value of the detector transformer magnetising current. <IMAGE>