Method of reducing RMS load voltage in a lamp using pulse width modulation
View Patent ↗A method of converting a line voltage to an RMS load voltage in a lamp includes modulating a load voltage with a pulse width modulation circuit that is entirely within the lamp and provides an RMS load voltage to a light emitting element of the lamp. Conduction is triggered in the pulse width modulation circuit independently of a line voltage magnitude with a time-based signal source that defines a duty cycle of the pulse width modulation circuit suitable for the RMS load voltage.
1. A method of converting a line voltage to an RMS load voltage in a lamp, the method comprising the steps of:
pulse width modulating a load voltage with a pulse width modulation circuit that is entirely within the lamp and provides an RMS load voltage to a light emitting element of the lamp;
triggering conduction in the pulse width modulation circuit independently of a line voltage magnitude with a time-based signal source that defines a duty cycle of the pulse width modulation circuit suitable for the RMS load voltage; and
clipping the line voltage in a dimmer circuit before the pulse width modulating step.
2. The method of claim 1 , wherein the time-based signal source is one of a pulse generator, a microcontroller and a clock.
3. The method of claim 1 , wherein the pulse width modulation circuit includes a transistor switch whose gate receives signals from the time-based signal source to trigger conduction of the pulse width modulation circuit.