Patent ID: 7595613

Claim:
An AC to AC power controller having an output for connection to a load, the controller comprising: a power regulator circuit comprising: first, second, third and fourth independently controllable switches, wherein the first switch is connected to the second switch, the second switch is connected to the third switch, and the third switch is connected to the fourth switch; and an inductor connected to at least one of the switches; a polarity detector in parallel with an input voltage to the power regulator; a duty cycle modulator; and a logic control circuit comprising a first output connected to the first switch, a second output connected to the second switch, a third output connected to the third switch and a fourth output connected to the fourth switch, wherein the logic control circuit is connected to receive as input at least one output of the polarity detector and at least one output of the duty cycle modulator, and wherein the logic control circuit is configured to control the first, second, third and fourth switches such that there is always an electrically conducting path through the switches and such that at least one switch is conducting.