Editing Light switch (section)

===Illuminated switch===
[[File:Illuminated light switch.jpg|thumb|upright|A UK illuminated rocker switch in the off position]]

Illuminated switches incorporate a small [[neon lamp]] or [[LED]], allowing the user easily to locate the switch in the dark. Household illuminated switches were introduced in the mid-1950s.<ref>{{cite journal |title=What's New for Your Home |journal=Popular Mechanics |date=March 1955 |access-date=12 February 2013 |page=131 |url=https://books.google.com/books?id=fNwDAAAAMBAJ&q=1954%20Popular%20Mechanics%20January&pg=PA131 |url-status=live |archive-url=https://web.archive.org/web/20130527194536/http://books.google.com/books?id=fNwDAAAAMBAJ&lpg=PA100&dq=1954%20Popular%20Mechanics%20January&pg=PA131#v=onepage&q&f=true |archive-date=27 May 2013 }}</ref>

Single-pole illuminated switches derive the power to energize their in-built illuminating source (usually, a "neon" lamp) from the current passing through the lamp(s) which they control. Such switches work satisfactorily with incandescent lamps, halogen lighting, and non-electronic fluorescent fixtures, because the small current required for the switch's illuminating source is too small to produce any visible light from such devices controlled by the illuminated switch. However, if they control only [[compact fluorescent lamp]]s (CFLs) and/or [[LED lamp]]s, the small amount of current required to energize the lighting source within switch also slowly charges the internal input capacitor in the electronic [[ballast]] of the CFL or LED until the voltage across it rises to the point where it produces a brief discharge through the CFL. This cycle may repeat indefinitely, resulting in repetitive brief flashing of the lamp(s) (and the light inside the switch) while the illuminated switch is in the "off" position.

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