Electrosurgical apparatus having RF pulse profile controller

A pulsed RF cut waveform profile for electrosurgery, in which each pulse is formed of a composite of different pulse portions. The pulse includes a controllable treatment portion whose duration can be truncated as necessary to ensure that the average power delivered by the pulse as a whole does not exceed a predetermined value. A limit for the average power delivered by the composite pulse (i.e. total energy delivered over the duration of the ON and OFF portions divided by the pulse duration) may be selectable by the operator. The ON portion may have multiple sub-portions, which have different purposes. Each pulse may be automatically controlled for pulse width in this manner, so that the RF signal effectively responds intelligently to conditions at the probe tip during treatment.