Abstract: The present invention relates to apparatus used in power control, such as apparatus for controlling the power level in an AC electrical circuit. Such an apparatus is referred to as an AC power converter. In one form, the present invention particularly relates to a power converter suitable for use in lighting dimmer control although other applications of the present invention are not to be excluded from the scope of the present application. A number of aspects of the power converter are disclosed.

Abstract: A power converter is disclosed. In one embodiment, the power converter includes an input for receiving a supply power; a switching device for controlling of power delivered to an output load; a controller for controlling the operation of the switching device; a first and second sensing circuit for providing first and second signals indicative of voltage and current inputs, respectively, to the converter; and a detector to detect a difference in polarity between the first and second signals; wherein the switching device is operable to switch between a first and second state, the first state being ‘on’ and the second state being ‘off’, and wherein the controller causing the switching device to be in the first state responsive to a detected difference in polarity between the signals to thereby dissipate a residual energy in the power converter.