Corona discharge detecting device

A corona discharge detecting device comprising:

• a horizontal deflection pulse generating circuit;
• a high voltage output circuit coupled to said pulse generating circuit for generating output pulses having frequency components in the same frequency range as said corona discharge;
• a flyback transformer including a primary coil coupled to said high voltage output circuit, a high voltage coil and a third coil;
• a tuned coupling circuit tuned to a frequency between 4.2 MHz and 50 MHz, said tuned coupling circuit including a magnetic core having an opening therein, a conductor connecting the high voltage and third coils of said flyback transformer passing through said opening, and a detecting coil wound on said core;
• a tuned amplifier coupled to the detecting coil of said flyback transformer, said tuned amplifier being tuned to the same frequency as said coupling circuit;
• and
• an oscilloscope having its input connected to the output of said tuned amplifier, corona pulses occurring in said flyback transformer being displayed on said oscilloscope as unsynchronized pulses.