Push=pull power converter circuit - has transformer bridge and alternately closed switching bridge reducing voltage loading

摘要

A push-pull power converter circuit contains a transformer (Tr) whose secondary coil drives a rectifier, filter, and load. Each primary coil (W1) half is connected in a side branch of a bridge circuit with one of two alternately closed switches (S1, S2) driven by a pulse width regulator (PBR). The diagonal bridge arm contains a direct voltage source (Uo) and choke (U) connected in series between the switch junction and primary coil centre tapping. Its blocking voltage loading and switching transistor power loss are essentially reduced compared to conventional circuits. It produces a continuous output current and requires relatively small additional component cost. An additional bridge circuit is formed with its side branches each contg. a primary coil half and one of two further alternately closed switches (S1', S2') driven by (PBR). The diagonal arm contains a further choke (L2) magnetically coupled to the first choke (L1).