I created these faux candles back in 2002 to solve my problem of wanting the look of candles in my haunted house without the risk or problems that having real candles with an open flame present.  The design allows for up to 15 candles be controlled from a single circuit board making it very economical to build multi candle chandeliers and candelabras.

 The core of the controller is an Atmel microcontroller that is used to generate the PWM (pulse width modulation) signal.  This signal has the effect of varying the voltage across the led as the on-off time is varied generating a small variation in the output intensity of the led giving the appearance of a burring candle.  A secondary timer is used to generate a semi random off state of the led to give the effect of a breeze or air movement.

 

Development circuit while firmware was being created

Circuit boards back from Bolgaria