High-voltage apparatus for skin therapy

Claim 1

An improved high voltage apparatus for skin therapy comprising: a low voltage DC power source having fixed and variable voltage outputs; a DC-to-DC converter, having (i) a converter oscillator powered by the variable voltage output of the DC power source, (ii) a converter step-up transformer, the primary winding(s) of which are fed by the oscillator, (iii) a rectifier circuit connected to the secondary winding of the converter step-up transformer, and (iv) a filter capacitor in shunt across the rectifier output; an output transformer; a second capacitor, connected in series with the output from the DC-to-DC converter and the primary winding of the output transformer; a silicon-controlled rectifier, the anode and cathode of which are connected so as to cause discharge of the second capacitor across the primary winding of the output transformer whenever the silicon-controlled rectifier is triggered into conduction by a suitable pulse between its gate and source; a second oscillator, powered by the fixed output of the DC power source; an emitter-follower amplifier, also powered by the fixed output of the DC power source, the input of which amplifier is connected to the second oscillator and the output of which is connected to the gate of the silicon-controlled rectifier, so as to trigger the rectifier once per cycle of output of the second oscillator; and a skin therapy electrode connected to the secondary winding of the output transformer.