Discharge lamp auxiliary power supply - has separate oscillator and independently powered regulation circuit providing high stability lamp voltage

摘要

The power supply provides a high stability light output. The supply is driven from an AC power source, the reservoir capacitor voltage being stabilised by a single transistor acting as a switch across a non-filtered DC generator via a load inductance. The reservoir capacitor is fed from this inductance and the supply oscillator via a choke and diode the capacitor loop being completed via the transistor emitter and a series CR circuit to the generator. The stabilising transistor is controlled from a regulation circuit separately powered by a rectifier and shunt capacitors. The regulation circuit operates as a function of inputs from a potentiometer across the supply and from the supply oscillator. A diode connected in the opposite conduction sense across the transistor discharges diode and inductance self capacities.