The starter closes a circuit to preheat the lamp electrodes andopens it again at the end of the preheating time (approx. 0.5 - 2 s depending on the type of lamp), thus creating the voltage surge required to ignite the lamp even at low ambient temperatures and mains undervoltage. The average make time of the starter contacts (preheat time) and the surge voltage level are important factors for the service life of fluorescent lamps.
Three types of starter are in common use :
glow starters with safety shutdown
- electronic starters integrated in quick-start units
The main differences relate to flicker during starting and at the end of lamp life. In the case of the simple glow starter, lamp start may only succeed after several attempts, whereas the other types provide more or less flicker-free starting.
At the end of lamp life, a glow starter will make repeated attempts to achieve re-ignition (flicker). The more sophisticated starters incorporating a thermoswitch or electronic components interrupt the current after 1-3 min. (no flicker). Once the lamp has ignited, the voltage in the glow starter is reduced to lamp voltage, which is not enough to re-ignite the glow discharge in the starter.
In the case of simple capacitive ballasts, contact make time is too short. This leads to repeated attempts at ignition without adequate preheating in the electrodes, which reduces lamp life.