To have a neon lamp properly switched on, two specific appliances are required. These are the starter and the reactor:
The starter acts as a timer switch, consists of two electrodes contained in a glass ampule containing inert gases.
The ampoule is in turn contained in a metal tube. At start-up, the starter switches on current for 1-2 seconds then opens the circuit.
This timing is necessary to cause incandescent discharge filaments to glow in the gas contained in the lamp.
![neon lamp reactor](/files/95/reattore_lampada_neon.jpg)
The reactor instead it regulates the current intensity of the lamp, allows it to be switched on and then enables the power supply.