Control modulator for power transistors - has further transformer in sec. load circuit of driver transformer providing current feedback

摘要

The control modulator (M) has a switched driver stage (3) contg. a driver transformer (DT) with a coupling winding (CWP) in its load current path providing a current feedback for the base of at least one power transistor (PT1, PT4). The coupling winding (CWP) acts as the primary winding of a further transformer with its winding (CWS) connected in parallel with the primary winding (PW) of the driver transformer (DT). Pref., the winding (CWS) of the further transformer can be short-circuited. ADVANTAGE - Optimal current and resistance transformation.