Power Factor Control For An LED Bulb Driver Circuit
AssigneeSwitch Bulb Company, Inc.
InventorsStanley CANTER, John D. Grainger
Life of this patent
Estimating the term…
Abstract
A light-emitting diode (LED) bulb has a shell and a base attached to the shell. An LED is within the shell. A driver circuit provides current to the LED. The driver circuit has a power factor control circuit that includes a tracking circuit configured to produce a tracking signal indicative of the voltage of the supply line. The power factor control circuit also includes a switch-mode power supply (SMPS) controller having an input pin and an output pin. The tracking circuit is connected to the input pin. Based on the signal at the input pin, the SMPS controller is configured to change a duty cycle of an output signal on the output pin.
Claims17
A light-emitting diode (LED) bulb comprising:
- a shell;
- an LED contained within the shell;
- a driver circuit for providing current to the LED, the driver circuit having a power factor control circuit that comprises:
- a tracking circuit connected to a supply line to the LED, wherein the tracking circuit is configured to produce a tracking signal indicative of the voltage of the supply line;
- a switch-mode power supply (SMPS) controller having an input pin and an output pin, wherein the tracking circuit is connected to the input pin,
- wherein, based on the signal at the input pin, the SMPS controller is configured to change a duty cycle of an output signal on the output pin;
- and
- a base attached to the bulb for connecting the LED bulb to an electrical socket.
A light-emitting diode (LED) bulb comprising:
- a shell;
- an LED contained within the shell;
- a driver circuit for providing current to the LED, the driver circuit comprising:
- an input filter configured to produce a rectified voltage output based on an input line voltage;
- and
- a switch-mode power supply (SMPS) controller connected to the input filter, wherein the SMPS controller is configured to control a drive current to the LED,
- wherein, in response to an alternating current (AC) voltage input, the input filter is configured to store approximately zero energy from one cycle of the AC voltage input to the next cycle;
- and
- a base attached to the shell for connecting the LED bulb to an electrical socket.
A light-emitting diode (LED) bulb driver circuit comprising:
- an input filter for producing a rectified voltage output based on an input line voltage;
- and
- a switch-mode power supply (SMPS) controller connected to the input filter, wherein the SMPS controller is configured to supply a drive current to an LED in the LED bulb,
- wherein, in response to an alternating current (AC) voltage input, the input filter is configured to store approximately zero energy from one cycle of the AC voltage input to the next cycle.
Dependencies are inferred from the claim text.