View source for Key switch

{{other uses|Keyswitch (disambiguation){{!}}Keyswitch}}
{{Infobox electronic component
| name              = Key switch
| image             = Key switch.jpg
| caption           = On/off key switch
| type              =
| working_principle = [[Switch]]
| invented          =
| first_produced    =
| pins              =
| symbol            = [[File:IEEE 315 Contacts, Switches, Contactors, and Relays Symbols (78).svg]]
| symbol_caption    =
}}
A '''key switch''' (sometimes called a keyswitch or lock switch) is a [[Key (lock)|key]]-operated [[switch]].<ref>{{cite book |last1=Martston |first1=R. M. |title=Security Electronics Circuits Manual |date=1998-07-15 |publisher=Newnes |isbn=978-0-08-093854-7 |url=https://books.google.com/books?id=N1brCyiY1OgC&dq=key+operated+switch+types+of+switches&pg=PA10 |language=en}}</ref> Key switches are used in situations where access to the switch's functions needs to be restricted.<ref>{{cite book |last1=Safety) |first1=Center for Chemical Process |title=Guidelines for Safe Automation of Chemical Processes |date=2017-01-06 |publisher=John Wiley & Sons |isbn=978-1-119-35189-4 |url=https://books.google.com/books?id=VpXbDQAAQBAJ&dq=key+switch+security+access+restricted&pg=PA119 |language=en}}</ref><ref>{{cite book |last1=Schum |first1=John L. |title=Electronic Locking Devices |date=1988 |publisher=Butterworths |isbn=978-0-409-90125-2 |url=https://books.google.com/books?id=0DBSAAAAMAAJ&q=key+switch+access+restricted |language=en}}</ref>

Key switches are available as [[Electronic component|components]] with solder connections, and are available with a variety of [[ampere]] ratings. They may use tubular or other specially-shaped keys for extra security.<ref name="maplin" />

Key switches have been used for a variety of purposes, up to and including the launch of [[nuclear missiles]].<ref name="dodimagery" />

In less secure applications such as [[staircase timer|corridor]] and restroom lighting controls in public buildings, [[tamper-resistant switch]]es with a simpler key mechanism may be used instead.<ref>{{cite web|title=Low-Cost Security Measures for School Facilities|url=http://www.ncef.org/pubs/low_cost_measures.pdf|publisher=National Clearinghouse for Educational Facilities|accessdate=1 September 2014|archive-date=25 May 2012|archive-url=https://web.archive.org/web/20120525203558/http://www.ncef.org/pubs/low_cost_measures.pdf|url-status=dead}}</ref><ref >{{cite web|title=Product Bulletin for 30 Amp AC Toggle Switches|url=http://www.leviton.com/OA_HTML/ibcGetAttachment.jsp?cItemId=xreQ9kM.SwSAGa6JaqTCzw|publisher=Leviton|accessdate=1 September 2014|archive-date=6 April 2023|archive-url=https://web.archive.org/web/20230406114047/https://www.leviton.com/OA_HTML/ibcGetAttachment.jsp?cItemId=xreQ9kM.SwSAGa6JaqTCzw|url-status=dead}}</ref>

== References ==
{{commonscat|Key switches}}
{{Reflist|refs=
<ref name="maplin">{{cite web | url=http://www.maplin.co.uk/c/components/switches/key-switches | title=Key switches | publisher=[[Maplin Electronics]] | accessdate=23 August 2014}}</ref>
<ref name="dodimagery">{{cite web | url=http://dodimagery.afis.osd.mil/imagery.html#a=search&s=simulation%20of%20a%20Peacekeeper%20Missile%20Launch&t=0&guid=0f307fd0b6d2c847b0c0e2dcbaac7a20a6f6a092 | title=Simulation of a Peacekeeper missile launch | publisher=Defence Imagery | accessdate=23 August 2014 | archive-date=28 September 2015 | archive-url=https://web.archive.org/web/20150928222135/http://dodimagery.afis.osd.mil/imagery.html#a=search&s=simulation%20of%20a%20Peacekeeper%20Missile%20Launch&t=0&guid=0f307fd0b6d2c847b0c0e2dcbaac7a20a6f6a092 | url-status=dead }}</ref>
}}

{{Switches}}

[[Category:Switches]]
[[Category:Locksmithing]]


{{Electronics-stub}}