Patent ID: 8536499

Claim:
A power supply for an RF generator, the power supply comprising: a first switched mode power supply (SMPS), and a second SMPS connected in series to the first SMPS by a DC bus including a capacitor connected between outputs of the first SMPS and between inputs of the second SMPS, the outputs of the second SMPS being connected to an input of a step-up transformer, an output of the step-up transformer being connected to an input of a rectifier and an output of the rectifier being connectable to the RF generator, wherein an input of the first SMPS is connectable to a prime power input to set an operating voltage and peak current level for the RF generator and the second SMPS is arranged to feed the step-up transformer and to operate with a variable duty cycle and/or variable frequency to provide average power control of the RF generator wherein an output of the rectifier is connected to the RF generator without filtering or smoothing therebetween so that only minimal energy is stored by the power supply such that the second SMPS can be rapidly switched off.