High Voltage and Low Current Supply

This is the design for power supply that is a very useful source which can be effectively used in many applications like biasing of gas-discharge tubes and radiation detectors etc. This is the figure of the circuit.


In this configuration, the primary winding and the feedback winding are arranged such that a sustaining oscillation is ensured once the supply is switched on. The waveform’s duty cycle is asymmetrical, but it is not very important in this application. Please note that if the oscillations do not occur at the ‘switch-on’ time, the transformer winding terminals of the feedback or the primary winding (but not both) should be reversed. The primary oscillation amplitude is about 24V(p-p). This gets amplified with the large step-up ratio of the transformer and we get about 800V(p-p) across the secondary. A simple series voltage multiplier (known as Cockroft-Walton circuit) is used to boost up this voltage in steps to give a final DC of about 2 kV. The output voltage, however, is not very well regulated. But if there is a constant load, the final voltage can be adjusted by varying the supply voltage.