Light emitting diode thermal foldback control device and method
A thermal foldback control system including a temperature sensitive circuit configured to output a reference voltage corresponding to a temperature of at least one selected from a group consisting of a light emitting diode (LED) driver, a LED engine, and a LED, wherein a driver output of the LED driver is based on the reference voltage.
1. A thermal foldback control system comprising:
a temperature sensitive circuit configured to output a reference voltage corresponding to a temperature of at least one selected from a group consisting of a light emitting diode (LED) driver, a LED engine, and a LED;
wherein a driver output of the LED driver is based on the reference voltage; and
wherein a connection between the temperature sensitive circuit and the at least one selected from the group consisting of the LED driver, the LED engine, and the LED is a mechanical and thermal connection.
2. The thermal foldback control circuit of claim 1 , wherein the driver output powers one or more light emitting diodes (LEDs).
3. The thermal foldback control circuit of claim 1 , wherein the reference voltage is based on a first resistance from a first resistance component and a second resistance from a second resistance component.
4. The thermal foldback control circuit of claim 3 , wherein the first resistance component is at least one selected from a group consisting of a negative temperature coefficient (NTC) type thermistor and a positive temperature coefficient (PTC) type thermistor.
5. The thermal foldback control circuit of claim 3 , wherein the second resistance component is at least one selected from a group consisting of a negative temperature coefficient (NTC) type thermistor and a positive temperature coefficient (PTC) type thermistor.
6. The thermal foldback control circuit of claim 1 , further comprising a regulator.
7. The thermal foldback control circuit of claim 6 , wherein the regulator is a shunt regulator.
8. The thermal foldback control circuit of claim 6 , wherein the regulator includes at least one selected from a group consisting of a Zener diode, an avalanche breakdown diode, and a voltage regulator tube.
9. The thermal foldback control circuit of claim 6 , wherein the regulator decreases a drive current in response to the reference voltage crossing a predetermined threshold.
10. The thermal foldback control circuit of claim 9 , wherein the predetermined threshold is related to a predetermined temperature at a reference point.
11. The thermal foldback control circuit of claim 1 , further comprising a capacitor in a parallel-type configuration with a second resistance component providing a second resistance.
12. A method of controlling power to one or more light emitting diodes (LEDs), the method comprising:
outputting, via a temperature-sensitive circuit, a reference voltage corresponding to a temperature of at least one selected from a group consisting of a light emitting diode (LED) driver, a LED engine, and a LED; and
controlling one or more LEDs based on the reference voltage;
wherein a connection between the temperature sensitive circuit and the at least one selected from the group consisting of the LED driver, the LED engine, and the LED is a mechanical and thermal connection.
13. The method of claim 12 , the LEDs are controlled via the LED driver.
14. The method of claim 12 , wherein the reference voltage is based on a first resistance from a first resistance component and a second resistance from a second resistance component.
15. The method of claim 14 , wherein the first resistance component is at least one selected from a group consisting of a negative temperature coefficient (NTC) type thermistor and a positive temperature coefficient (PTC) type thermistor.
16. The method of claim 14 , wherein the second resistance component is at least one selected from a group consisting of a negative temperature coefficient (NTC) type thermistor and a positive temperature coefficient (PTC) type thermistor.