Capacitive current limiting inverter

Claim 1

A high voltage AC power supply having means for limiting peak capacitive current into a load having a substantial capacitive component, comprising: a DC electrical energy source; a pulse-width modulated (PWM) inverter for converting DC electrical energy to AC electrical energy; a transformer including a pair of output terminals for connection to the load, the transformer serving to transform the AC electrical energy from the inverter to high voltage AC electrical energy to be delivered to the load and to provide isolation between the DC electrical energy source and the AC electrical energy delivered to the output terminals; means for providing to the PWM inverter a reference voltage waveform having substantially linear rise and fall times and having a substantially flat top during positive and negative peaks for synthesizing an inverter output voltage waveform having substantially the same shape as said reference voltage waveform; whereby, peak capacitive current at the transformer output terminals and thus through the switching elements of the inverter is limited during the rise and fall times by the shape of the inverter output voltage waveform to a value substantially less than a waveform with exponential rise and fall times.