Patent ID: 8106613
Filing Date: 2012-01-31
Classification: H02M

Abstract:
1. A drive circuit for a motor having a plurality of phases, the drive circuit comprising: an input for a DC signal; a plurality of phase outputs, the circuit being arranged to provide at each of the phase outputs, in use, current to one phase of the motor; a plurality of converters, with a single converter associated with each phase output, each converter being arranged to take as an input a DC signal and output a signal having an AC component with a higher voltage magnitude than that of the DC signal input to the converter, each converter including a pair of switches; and a control device arranged to, in use, apply control signals to the switches of each of the converters, the control device being arranged to switch the switches in use at a certain frequency, and to vary the duty ratio of such switches in order to generate the AC component.