The inverter includes a low voltage microcontroller referenced to ground potential and a waveform generator coupled to the microcontroller through a serial data link including optical isolation devices. The waveform generator floats at the negative bus potential of the DC source for the inverter. The...http://www.google.ca/patents/US4994950?utm_source=gb-gplus-sharePatent US4994950 - Waveform generator for inverter control
