Design of intrinsically safe circuits and secondary heat dissipation

Design of intrinsically safe circuits and secondary heat dissipation

（1）LED is a current-driven component. The working current has a linear relationship with voltage and luminous efficiency. That is, the larger the working current, the higher the voltage, and the higher the luminous efficiency. However, exceeding the rated operating current will shorten the LED life. When the voltage is increased from 3.1 V to 3.42 V (rated operating voltage), the current changes up to 250 mA with a change rate of 781 mA / V. It can be seen that the working current is very sensitive to voltage changes, and the current changes directly affect The luminous efficiency of LEDs must be intrinsically safe when designing circuits and keep constant output to the LED terminals.

（2）Secondary cooling problem

For the heat dissipation of the LED, a large-area chip flip-chip structure, a metal circuit board structure, a heat conduction groove structure, and a microfluidic array structure are used in the packaging structure. In terms of material selection, select a suitable substrate material and paste material, and use silicone resin. Instead of epoxy. However, the secondary heat dissipation of LED lighting lamps is still a key issue in the current production of lighting lamps. The measures that can be taken are to fix the LED diodes on the Al plate or Al sheet; then, the Al plate or Al sheet is fixed to the housing with thermal grease Together, the heat generated by the LED diodes is quickly dissipated through the housing. Experiments have proved that the effect is very good and meets the requirements of light emission and energy saving.