Neon lamp

Neon lamp

Neon lamps are small bulbs filled with neon and used as indicator bulbs producing a orange/red glow. 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.

A neon lamp can be exited by AC or DC. In AC exited lamps, both electrodes produce light and glow, but in a DC exited lamp, only one electrode glows. This simple fact can be used to distinguish between AC and DC sources using a neon lamp.

In addition to many other uses they were used as very simple voltage regulators in the days of tube electronics. Neon lamps were also used for a variety of other purposes in olden times. A good set of links describing those is :

External Links

http://www.tinaja.com/glib/elesimp.pdf

http://www.tinaja.com/glib/muse136.pdf

http://www.tinaja.com/glib/resbar02.pdf

and more at the same site.