Power supply with pulse modulated control circuit - has voltage rectified via self inductor during switching phase of transistor

摘要

The mains connected supply system has a switching transistor and a control and regulating circuit which has a pulse width modulating stage which reacts to the ratio between the desired and actual value. It also contains an overload protection circuit which limits the switching transistor when a predetermined energy storage current is reached. This achievement is a voltage supply for a t.v. receiver. A voltage is rectified (27) via the self-induction of the power supply during the transmission phase of the switching transistor (6). This is used to generate the supply voltage for the remote control circuit (6). The circuit contains a resistance matrix in the pulse width modulation stage which produces a negative current to reduce the voltage of the remote control circuit.