METHOD OF MEASURING THE THERMAL IMPEDANCE OF LEDS Russian patent published in 2017 - IPC G01R31/00 

FIELD: physics.

SUBSTANCE: sequence of pulses of heating current _IGr, Pulse-width modulated by harmonic law, with a modulation frequency Ω and the depth of modulation a; during the action of the heating current pulses, the voltage across the LED and the central wavelength of the LED light with a known temperature coefficient T_Cλ, the measurement results determine the amplitude of the first harmonic of the heating power P_m1(Ω), Consumed by the LED, and the amplitude of the first harmonic of the central wavelength of the LED light , as well as the phase shift between them ϕ(Ω) at the modulation frequency of the heating power, the average power of the optical radiation of the LED is average during the modulation period , and the thermal impedance module is found by the formula , and the phase ϕ_T (Ω) of the thermal impedance of the LED is determined as the phase difference between the first harmonic of the central wavelength of the LED emission and the first power harmonic.

EFFECT: increasing the accuracy of the measurement of thermal impedance.

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