Why do many fluorescent lamps blink before they come on?
The lamp first heats the filaments in its electrodes red hot so that they begin to emit electrons and then tries to start a discharge across the lamp. If there are not enough electrons leaving the electrodes to sustain a steady discharge, the lamp will blink briefly but will not stay on. The lamp will try again; first heating its filaments and then trying to start the discharge. The lamp may blink several times before the discharge becomes strong enough to keep the electrodes hot and sustain the discharge.