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-operated switch.{{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}} Key switches are used in situations where access to the switch's functions needs to be restricted.{{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}}{{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}}

Key switches are available as 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.

Key switches have been used for a variety of purposes, up to and including the launch of nuclear missiles.

In less secure applications such as corridor and restroom lighting controls in public buildings, tamper-resistant switches with a simpler key mechanism may be used instead.{{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}}{{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}}