Practical Design of An LED Flashlight

This chapter discusses design of a battery‐powered light‐emitting diode (LED) flashlight and begins the actual design by making a first pass at the number and type of LEDs required, and estimating the power they require. Then it chooses a control IC and also real components from a distributor's website, to make the design manufacturable. After estimating the power needed for the LED, the next task is to design its power supply and estimate its power dissipation to calculate the LED temperature. To do this, it is need to create a thermal model for the flashlight. The first link in the path from the LED to the ambient is from the LED junction to the solder point. The next link in the thermal path is the way the LED is mounted. For this design, metal core printed circuit board (MCPCB) is used.