Patent ID: 7196480

Claim:
A method of operating a power controller that converts a line voltage to an RMS load voltage and that has a phase-control clipping circuit that clips a load voltage to define a conduction angle that sets the RMS load voltage, the circuit including a time-based signal source that sends signals to trigger conduction in the circuit independently of line voltage magnitude and a transistor switch whose gate receives the signals from the time-based signal source, the method comprising the steps of: when starting the power controller, increasing the conduction angle of the phase-control clipping circuit, the conduction angle increasing in plural steps from a first value to a steady state value; and during subsequent operation of the power controller, sending the signals from the time-based signal source with the steady state value of the conduction angle at constant time intervals to the gate of the transistor switch to cause the power controller to provide the RMS load voltage independently of line voltage magnitude.