Analysis of ignitron switching characteristics for burst mode operation of dual and off resonance high frequency power supplies

Analytical and experimental studies of a unique application of an ignitron are presented. The ignitron was controlled using an RC network which slowed the transient turn-on time from a fast sub-microsecond to a slower microsecond voltage fall-time. The ignitron was in series with a primary circuit of 8 nF (charged to several kilovolts) and 500 μH of the transformer primary. In an effort to block the power supply frequencies (tens to hundreds of kilohertz), a 2 MHz high-pass filter was used to pass only the corona signature. Results showed that the original 20 V of noise for fast fall times was successfully reduced by 40 dB using a 1 μs fall-time. This 40 dB is sufficient reduction for protecting small signal preamplifiers, so that after not more than two to five cycles, corona signal can be seen at 2 to 5 mV