Method of operating a lamp containing a fixed phase power controller
View Patent ↗A method of operating a lamp that has a power controller connected between a terminal and a light emitting element that converts the line voltage to an RMS load voltage. An input to an analog control block is provided in the controller that is independent of a change in magnitude of the line voltage. A trigger signal from the analog control block is provided at a first frequency by charging and discharging a capacitor in the analog control block that receives the input. An initial condition of the analog control block is resetted periodically. A sync signal synchronizes the trigger signal with a waveform of the line voltage. A load voltage is clipped based on the synchronized trigger signal to define the RMS load voltage.
1. A method of operating a lamp that has a terminal for a line voltage, a light emitting element, and a power controller connected between the terminal and the light emitting element that converts the line voltage to an RMS load voltage, the method comprising the steps of:
providing an input to an analog control block in the controller that is independent of a change in magnitude of the line voltage;
providing a trigger signal from the analog control block at a frequency by charging and discharging a capacitor in the analog control block that receives the input;
resetting periodically an initial condition of the analog control block;
providing a sync signal that synchronizes the trigger signal with a waveform of the line voltage; and
clipping a load voltage by triggering a switch off and on based on the synchronized trigger signal to define the RMS load voltage.
2. The method of claim 1 , wherein the input is from a DC source.
3. The method of claim 1 , wherein the sync signal is provided to the analog control block.
4. The method of claim 1 , wherein the sync signal is provided to a reset circuit that performs the resetting step.