Usage time correcting engine

摘要

A usage time correcting engine, and corresponding method, system, apparatus, and computer product are provided. Over a period of time that an LED lighting fixture is being used to provide light, a usage time correcting engine indirectly measures an internal temperature of a component of the fixture. The indirect measurement is based on a measured external temperature of the component and power output supplied to or provided by the component. The usage time correcting engine determines a multiplier as a function of the indirectly measured internal temperature. The usage time correcting engine multiplies the period of time by the multiplier to provide a corrected measurement of usage of the component. In some examples, the usage time correcting engine determines a remaining lifetime of the LED lighting fixture from the corrected measurement and then reports the remaining lifetime to a user by way of a log, flashing light or other notification/indication.

主权项

1. A method for correcting a measurement of usage of a light emitting diode (LED) lighting fixture component for determining the life expectancy of the LED, each LED having a junction to ambient thermal resistance (RθjA in ° C./W), the method comprising:
in a microprocessor of a LED lighting fixture, over a period of time that the LED lighting fixture is being used to provide light; measuring, in the LED lighting fixture, a temperature (TA in ° C.) external to the component; measuring a power output (PD in W) supplied to or provided by the component; calculating an internal temperature of the component of the LED lighting fixture (TJ in ° C.) based on the equation: TJ=TA+(RθJA×PD); determining a multiplier as a function of the calculated internal temperature (TJ in ° C.); and multiplying the period of time by the multiplier to provide a corrected measurement of usage of the component.