Fixed frequency converter switching at zero voltage.

摘要

A converter is operated with a main switch in series circuit with primary winding of the isolation transformer and an auxiliary switch for charging a reset capacitor also in circuit with the primary winding. The main switch and auxiliary switch are operated through control logic so that neither switch is ON at the same time. A predetermined dead time is provided between turning OFF the auxiliary switch and turning ON the main switch to allow the output capacitance of the main switch to discharge to zero. The power is transferred to the output during the ON and OFF time of the main switch. The power can be transferred to the output also during only the off time. In the case when the power is transferred from the primary to the secondary during both ON and OFF time, an inductor or a saturable reactor is series circuit with the secondary or a selectively controlled rectifier is used. <IMAGE>