LED (light-emitting diode) temperature control method and system based on PWM (pulse width modulation)

Abstract

The invention discloses an LED (light-emitting diode) temperature control method and system based on PWM (pulse width modulation). The method comprises the following steps: detecting voltage U1 of a photoresistor through a controller and figuring out the brightness of an LED; calculating the current total power consumption W1 of the LED according to PWM duty ratio d1, performing power consumption table lookup according to the W1, finding out the light efficiency eta 1 which needs to be achieved by the LED at the current W1, calculating the current light efficiency eta 2 according to the brightness of the LED and the current total power consumption W1, comparing the eta 1 with the eta 2, screening out points with the total power consumption W2 which is lower than W1 according to a temperature-light efficiency curve if the eta 2 is less than the eta 1, calculating PWM duty ratio d2 according to the total power consumption W2 and adjusting a PWM output signal according to the d2 so as to always control the temperature of a circuit of the LED in an appropriate range, prevent the temperature from being too high and affecting the light efficiency of the LED. According to the method disclosed by the invention, the LED can work in the appropriate temperature range, fully play the light efficiency and realize the optimal balance among the brightness of the LED, the light efficiency and the temperature. The LED temperature control system disclosed by the invention is simple in structure and low in cost.

Description

technical field [0001] The invention relates to the technical field of temperature control of LED lighting equipment, in particular to a PWM-based LED temperature control method and system. Background technique [0002] Due to the advantages of long life, high efficiency, and energy saving, LEDs are more and more widely used in the field of lighting. However, the life of LED is closely related to the light efficiency and working temperature. When the temperature exceeds a certain value, the light efficiency and life will drop rapidly. Due to the decrease of light efficiency, the brightness of LED decreases, and more power consumption will be converted into heat energy and dissipated; if it is an LED with adjustable brightness, increasing the current in order to increase the brightness will further increase its calorific value, not only It will not achieve the purpose of increasing brightness, but will accelerate the aging of LEDs. [0003] At present, the temperature contr...

AI Technical Summary

Problems solved by technology

This method and equipment also have the problem that the temperature is difficult to measure and control accurately

At the same time, the composition of the hardware equipment required by this method is also relatively complicated, and the cost is correspondingly high.

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