Power supply for LEDs
AssigneeKoninklijke Philips Electronics N.V.
InventorsAjay Tripathi, Bernd Clauberg
Life of this patent
Estimating the term…
Abstract
The power supply for LEDs of the present invention provides power to a variable number of LEDs wired in series or in parallel. The power supply uses current feedback to adjust power to the LEDs and provides protection against open circuits and circuit malfunctions. A current controller compares sensed current to a reference current and generates a feedback signal, which is processed by a power factor corrector to adjust the current flow through the transformer supplying current to the LEDs.
Claims41
A system for supplying power for LEDs comprising:
- means for sensing current to the LEDs, the current sensing means generating a sensed current signal;
- means for generating a reference current signal;
- means for comparing the sensed current signal to the reference current signal, the comparing means generating a feedback signal;
- means for converting power responsive to the feedback signal, the power converting means supplying current to the LEDs;
- and
- means for protecting the LEDs.
A method of supplying power for LEDs comprising the steps of:
- sensing current to the LEDs and generating a sensed current signal;
- generating a reference current signal;
- comparing the sensed current signal to the reference current signal;
- generating a feedback signal based on the difference between the sensed current signal and the reference current signal;
- converting power and supplying current to the LEDs in response to the feedback signal;
- and
- protecting the LEDs.
A circuit for supplying power for LEDs comprising:
- a transformer, the transformer supplying current to the LEDs and being responsive to a transformer control signal;
- a current sensor for sensing current to the LEDs, the current sensor generating a sensed current signal;
- a current reference for generating a reference current signal;
- a current controller for comparing the sensed current signal to the reference current signal, the current controller generating a feedback signal;
- a PFC responsive to the feedback signal, the PFC generating a gate drive signal;
- a transistor responsive to the gate drive signal, the transistor generating the transformer control signal;
- and
- a protective circuit limiting the current to the LEDs.
A circuit for supplying power for LEDs comprising:
- a transformer, the transformer supplying current to the LEDs and being responsive to a transformer control signal;
- a current sensor for sensing current to the LEDs, the current sensor generating a sensed current signal;
- a current reference for generating a reference current signal;
- a current controller for comparing the sensed current signal to the reference current signal, the current controller generating a feedback signal;
- a PFC responsive to the feedback signal, the PFC generating a gate drive signal;
- a transistor responsive to the gate drive signal, the transistor generating the transformer control signal;
- and
- a protective circuit limiting the voltage to the LEDs.
Dependencies are inferred from the claim text.