| 摘要 |
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. Neon striation caused by negative resistance or non-linearity in the neon tube (typically responsive the changing voltage) is prevented by inductively tapping with few turns the primary of the output transformer. This inductively tapped power is fed back to a series connected capacitor in the oscillator voltage input circuit. Consequently, non-linearities or negative resistance is damped, prolonging tube electrode life and producing optimum neon glow. In the case of a neon lamp power supply, there results a light weight power supply having a small radio frequency inductance which strikes the neon lamp, maintains the neon lamp at minimum energy levels, adjusts the lamp to various changes in operating parameters, lessens fire danger and minimizes radio frequency interference.
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