Transistor chopped TV receiver supply - has transformer primary connected to collector and secondary feeding receivers through rectifier stages

摘要

The primary W(I) of the transformer (3) acts as a storage inductor in series with collector-emitter junction of a switching transistor (4) whose base is alternatively blocked and earthed. With the transistor (4) on, the inductance takes up energy while the damping diode (6) is off. Turning off the transistor directs the current to the primary through a capacitor (7) and a diode (6) connected to the earth. The transformer secondaries (W3, W4) are connected to rectifier stages (9) each with a diode and a capacitor. An auxiliary secondary winding (W/2 is coupled through a bypass loop which includes the driver and control unit (14).