A Transistorless Micromechanical High Voltage Generator Using a Dc-powered Self-oscillating Relay

This paper describes a DC powered high voltage generator that neither uses transistors nor requires a clock signal for its operation. The system, that operates on the principle of an induction coil voltage converter, is assembled using a self-oscillating mechanical relay and a wire wound inductance. Two versions of this high voltage generator have been implemented. The first version, assembled to have a footprint of less than 4 mm x 4 mm, uses an inductor and generates peak voltages > 200 V from a 4 V DC supply. An alternate version uses a transformer that provides electrical isolation and has been used to generate peak voltages > 500 V with a peak voltage gain > 300. The self oscillating relay is fabricated using low temperature UV-LIGA process, that can be appended to a CMOS process. Experimental results used to characterize system performance show that the self oscillating relay consumes not more than 15 % of input power. Circuit simulations closely track observed experimental trends.