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US 8,476,847 B2Granted
Thermal foldback system
AssigneeCRS Electronics
InventorScott Riesebosch
Life of this patent
Estimating the term…
Abstract
A thermal-foldback system detects an over-temperature condition in an LED lamp. In response to the over-temperature condition, the thermal-foldback system chops a portion of the input power waveform drawn by the LED lamp.
Claims19
A method for protecting an LED lamp from overheating, the method comprising:
- detecting an over-temperature condition in an LED lamp component;
- and
- chopping to substantially zero a portion of a waveform drawn by the LED lamp from a power supply, in response to the over-temperature condition, to thereby reduce power consumed by the LED lamp, wherein an unchopped portion of the waveform draws a current greater than a hold current of a component supplying the waveform to the LED lamp.
A system for protecting an LED in an LED lamp from overheating, the system comprising:
- a thermal sensor for detecting a temperature of an LED lamp component;
- and
- an LED driver circuit for chopping a portion of an input power waveform drawn by the LED lamp from a power supply in response to the detected temperature increasing past a threshold.
A driver circuit for converting a chopped signal waveform supplied by a system component into a power signal suitable for driving an LED, the circuit comprising:
- LED driver circuitry for receiving the chopped waveform and powering the LED based thereon;
- and
- a bleed controller for re-enabling the LED driver circuit during an a chopped portion of the waveform to bleed charge from the system component.
A system for protecting an LED in an LED lamp from overheating, the system comprising:
- a thermal sensor for detecting a temperature of an LED lamp component;
- and
- an LED driver circuit for chopping a portion of an input power waveform coming from a power supply powering the LED lamp in response to the detected temperature increasing past a threshold,
- wherein the input power waveform is chopped to reduce overall average input power to the LED lamp while maintaining a required minimum input power level for a component supplying the waveform during unchopped portions of the input power waveform.
1 more element
Dependencies are inferred from the claim text.