Abstract: A tuned circuit radio frequency power supply is disclosed. A conventional voltage doubler drives a power oscillator having a variable output frequency and variable amplitude input. The power oscillator output is connected to a tuned RLC circuit incorporating a load; a voltmeter coupled to the circuit measures overall phase of the RLC circuit and inputs to a phase comparator within the oscillator. Tuning of the RLC circuit is done by frequency comparison with circuit lead requiring increased oscillator frequency and circuit lag requiring decreased oscillator frequency. A switched resistance network preset for tube length, width and color of neon is placed in series with the oscillator input voltage. This resistance network outputs to an integrating amplifier, through an opto-isolator to control the amplitude of the oscillator input. The amplitude of the oscillator input thus controlled the output voltage of the RLC circuit to maintain optimum voltage for tube length, width and color of neon.

Abstract: A tuned circuit radio frequency power supply is disclosed. A conventional voltage doubler drives a power oscillator having a variable output frequency and variable duty cycle. The power oscillator output is connected to a tuned RLC circuit incorporating a load. A voltmeter coupled to the circuit measures overall phase of the RLC circuit and inputs to a phase comparator within the oscillator. Tuning of the RLC circuit is done by frequency comparison with circuit lead requiring increased oscillator frequency and circuit lag requiring decreased oscillator frequency. An ammeter is placed in series with the neon circuit and controls the oscillator duty cycle to maintain constant current despite changes in load. Consequently, power is adjusted from the oscillator, preferably by varying trigger level on a ramp voltage generator.