Electrical Control Gear for Lamps
Device(s) in the electric lamp circuit of gas discharge and solid-state lamps which limits the lamp current to the required value and ensures that the lamp can be started and once started can be operated stably over a longer period.
The devices needed are called igniters, ballasts, and, for LEDs, drivers.
Most of the gas discharge lamps have such a high internal resistance that they need a voltage peak, higher than the normal operating voltage, to initiate the discharge.
Igniters for Fluorescent Lamps
In most fluorescent lamp circuits, the electrodes are preheated for a few seconds before a high-voltage peak is applied across the lamp to initiate the discharge. Preheating of the electrodes facilitates the emission of electrons. Glow-switch starters were often used for this purpose. However, their harsh peak voltages have a negative effect on lamp life. Electronic starters with exactly the same functions as the glow-switch starter, but with a better-controlled...