High capacity transistor-based electric energy converter ensuring correct supply to e.g. fluorescent lamp electronic ballast

摘要

In the converter device, the rectified input voltage (+,-), eg. 50/60Hz mains supply, is applied across two parallel series-connected circuits, one including the two transistors (5A,5B), and the other, two capacitors (3A,3B). The HF output (E,F) is taken between the mid-points of each leg, e.g. via a transformer (9A,9B).A control transformer primary (6) is connected in series with the output. Its secondaries, inserted, with appropriate polarity, in series with limiting resistances (8A,8B), in the emitter (E) circuits, control the cyclic switching of the main current passing from each collector (C) to the associated base (B), the base of one transistor being connected to the collector of the other.