This simple 4W fluorescent lamp driver circuit diagram can be operated from a 12 V power supply. The first portion of the circuit includes a NE555 timer IC wired as an a stable multivibrator. The transistor Q1 amplifies the output pulses to the IC. The transformer steps up the the collector voltage to around 1KV to drive the fluorescent lamp. The R2 need to be set at full resistance before using the circuit. Then turn on the power supply, adjust R2 so that the collector current is 300 mA which is the lamp optimum setting because it would gives a better life for the lamp. Use the heat sink for transistor Q1 , a 3V primary, 230 V secondary, 5W transformer to W1. Power the circuit from a 12V battery or 12V DC power supply. The L1 can be a 6 inch 4W fluorescent lamp.
source : www.circuitstoday.com