Method and device for remote sensing and control of LED lights
First Claim
1. A method for determining a temperature of at least one light emitting diode (LED) in a circuit which includes (i) a power supply for powering the LED and (ii) a thermistor electrically connected in parallel with the LED, the thermistor having an effective resistance range that is lower than a reverse bias resistance of the LED and that is higher than a forward voltage resistance of the LED, where the LED is operable to generate light, the method comprising:
- providing an operating current and an operating voltage to the LED;
superimposing a current pulse on the operating current, superimposition of the current pulse causing a relatively larger amount of the current pulse to flow through the thermistor and a relatively smaller amount of the current pulse to flow through the LED;
determining a temperature of the thermistor based on the amount of the current pulse flowing therethrough;
sensing a magnitude of a voltage pulse across the LED resulting from the applied current pulse superimposed on the operating current; and
determining an operating temperature of the LED at the provided operating current based on a magnitude of the amount of the current pulse caused to flow through the LED and the magnitude of the voltage pulse.
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Accused Products
Abstract
A control system is disclosed for determining an actual temperature of a light emitting diode. The control system uses conductor that supply power to the light emitting diode to supply a pulse to the light emitting diode. The pulse is determined along with a reaction caused by the pulse and the information gained is used in determination of the light emitting diode die temperature which can then be used in controlling current to the light emitting diode to control the temperature of the light emitting diode.
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Citations
49 Claims
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1. A method for determining a temperature of at least one light emitting diode (LED) in a circuit which includes (i) a power supply for powering the LED and (ii) a thermistor electrically connected in parallel with the LED, the thermistor having an effective resistance range that is lower than a reverse bias resistance of the LED and that is higher than a forward voltage resistance of the LED, where the LED is operable to generate light, the method comprising:
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providing an operating current and an operating voltage to the LED; superimposing a current pulse on the operating current, superimposition of the current pulse causing a relatively larger amount of the current pulse to flow through the thermistor and a relatively smaller amount of the current pulse to flow through the LED; determining a temperature of the thermistor based on the amount of the current pulse flowing therethrough; sensing a magnitude of a voltage pulse across the LED resulting from the applied current pulse superimposed on the operating current; and determining an operating temperature of the LED at the provided operating current based on a magnitude of the amount of the current pulse caused to flow through the LED and the magnitude of the voltage pulse. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A control system for determining a temperature of at least one light emitting diode (LED) (i) receiving an operating current and an operating voltage and (ii) electrically connected in parallel to a thermistor having an effective resistance range that is lower than a reverse bias resistance of the LED and that is higher than a forward voltage resistance of the LED, the LED being operable at an operating temperature, the control system comprising:
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a power supply for providing the operating current and operating voltage to the LED, the power supply superimposing at least one current pulse on the operating current to the LED resulting in (i) a voltage pulse superimposed on the operating voltage and (ii) a relatively larger amount of the current pulse flowing through the thermistor and a relatively smaller amount of the current pulse flowing through the LED; a voltage sensor for determining a voltage magnitude of the voltage pulse; a current sensor for determining a current magnitude of the current pulse; and a controller for determining (i) the operating temperature of the LED at the provided operating current based on the current magnitude of the amount of the current pulse flowing through the LED and the voltage magnitude of the voltage pulse and (ii) a temperature of the thermistor based on the amount of the current pulse flowing therethrough. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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Specification