White LED Night Light



As many of you know, I have a pet peeve with poorly made LED night lights. Often, the light from the LED quickly fades, so within months, the light is useless. I have posted several versions of modified night lights using higher quality components. This circuit is yet another version, which produces much more light than those other designs. The circuit brings together two high power white LEDs made by Cree with a compact AC to DC power supply from Bias Power.

This simple circuit uses a one watt power supply module from Bias Power, model BPS1-08-00. The tiny module can crank out about 8 volts DC, fully isolated form the AC power line, whose voltage can range from 85vac to 250vac. The DC output of the module is fed to two one watt white LEDs, from Cree, wired in series. A 13 ohm � watt resistor in series limits the LED current to about 125ma. Although the LEDs are rated at one full watt, the circuit routes only one half watt into each part. The result is more than enough light for a night light and it should allow the light to last for many years.

I suggest mounting the two LEDs onto an aluminum bar or plate, to act as a heat sink. Excessive heat will shorten the life of the LED. You can remove the guts of a suitable night light and replace the internal parts with this circuit.

You can buy the Bias Power module at the address shown below. The Cree LEDs can be purchased from eBay. Other one watt LEDs may also work but may not last as long.

Click on Drawing Below to view PDF version of Schematic
Night Light White LED

 

/* EOT ----------------------------------------- */