ATAVRFBKIT: Dimmable Fluorescent Ballast

Fluorescent ballast topology usually includes line conditioning for CE and UL compliance, a power factor correction block including a boost converter to 400 V for universal input applications and a half bridge inverter.

By varying the frequency of the inverter, the controller will preheat the filaments (high frequency), then ignite the lamp (reducing the frequency). Once the lamp is lit, varying the frequency will dim the light. The Atmel AT90PWM2B/216 microcontroller can be programmed to perform all of these functions.