Neon lamp

Neon lamps are small bulbs filled with neon and used as indicator bulbs and as very simple voltage regulators in the days of tube electronics. This is not to be confused with neon signage. Neon lamps, in general, consist of a gas-discharge tube containing neon at low pressure and, when electified by alternating currents a luminescence is produced by the action of currents at high frequencies that are around the tube.