Electronic circuit to provide a starting voltage for another circuit - uses power supply to charge up capacitor, then thyristor fires to allow second capacitor to charge up

摘要

The patent describes an electronic circuit to give a starting voltage to a control circuit for a network (1), whose output (6) is connected to a cyclic switch (7) and which is supplied from the circuit (8) after the start of a cycle. The circuit has two parallel capacitors (11, 15) on either side of a thyristor (14). The first capacitor is charged up from the current source (9) to a threshold, after which the thyristor fires to allow the second capacitor to charge up. It is this second voltage which is the required starting voltage. After the cyclic switch has begun its cycle, the thyristor switches off. ADVANTAGE- Avoids overheating of components.