You do not have permission to edit this page, for the following reasons:

This IP address has been blocked from editing Wikipedia.
This does not affect your ability to read Wikipedia pages.
Most people who see this message have done nothing wrong. Some kinds of blocks restrict editing from specific service providers or telecom companies in response to recent abuse or vandalism, and can sometimes affect other users who are unrelated to that abuse. Review the information below for assistance if you do not believe that you have done anything wrong.

The IP address or range 44.195.0.0/16 has been blocked (disabled) by ‪Blablubbs‬ for the following reason(s):

The IP address that you are currently using has been blocked because it is believed to be a web host provider or colocation provider. To prevent abuse, web hosts and colocation providers may be blocked from editing Wikipedia.
You will not be able to edit Wikipedia using a web host or colocation provider because it hides your IP address, much like a proxy or VPN.
We recommend that you attempt to use another connection to edit. For example, if you use a proxy or VPN to connect to the internet, turn it off when editing Wikipedia. If you edit using a mobile connection, try using a Wi-Fi connection, and vice versa. If you are using a corporate internet connection, switch to a different Wi-Fi network. If you have a Wikipedia account, please log in.
If you do not have any other way to edit Wikipedia, you will need to request an IP block exemption.

How to appeal if you are confident that your connection does not use a colocation provider's IP address:
If you are confident that you are not using a web host, you may appeal this block by adding the following text on your talk page: ((unblock|reason=Caught by a colocation web host block but this host or IP is not a web host. My IP address is _______. Place any further information here. ~~~~)). You must fill in the blank with your IP address for this block to be investigated. Your IP address can be determined here. Alternatively, if you wish to keep your IP address private you can use the unblock ticket request system. There are several reasons you might be editing using the IP address of a web host or colocation provider (such as if you are using VPN software or a business network); please use this method of appeal only if you think your IP address is in fact not a web host or colocation provider.

Administrators: The IP block exemption user right should only be applied to allow users to edit using web host in exceptional circumstances, and requests should usually be directed to the functionaries team via email. If you intend to give the IPBE user right, a CheckUser needs to take a look at the account. This can be requested most easily at SPI Quick Checkuser Requests. Unblocking an IP or IP range with this template is highly discouraged without at least contacting the blocking administrator.

This block will expire on 09:46, 11 January 2025.

Even when blocked, you will usually still be able to edit your user talk page, as well as email administrators and other editors.

For information on how to proceed, please read the FAQ for blocked users and the guideline on block appeals. The guide to appealing blocks may also be helpful.

Other useful links: Blocking policy · Help:I have been blocked
Your IP address is in a range that has been blocked on all Wikimedia Foundation wikis. The block was made by ‪AntiCompositeNumber‬. The reason given is Open proxy/Webhost: Visit the FAQ if you are affected .
- Start of block: 13:55, 18 August 2022
- Expiry of block: 13:55, 18 January 2025
Your current IP address is 44.195.68.6. The blocked range is 44.195.0.0/16. Please include all above details in any queries you make. If you believe you were blocked by mistake, you can find additional information and instructions in the No open proxies global policy. Otherwise, to discuss the block please post a request for review on Meta-Wiki. You could also send an email to the stewards VRT queue at stewards@wikimedia.org including all above details.

You can view and copy the source of this page:

((Short description|Electric switch actuated by very little physical force))
((More citations needed|date=March 2011))
[[file:Microswitches.jpg|thumb|right|Comparison of some different switches]]

A '''miniature snap-action switch''', also trademarked and frequently known as a '''micro switch''' or '''microswitch''', is an electric [[switch]] that is actuated by very little physical [[force]], through the use of a [[Tipping point (physics)|tipping-point mechanism]], sometimes called an "over-center" mechanism.

The defining feature of micro switches is that a relatively small movement at the [[actuator]] button produces a relatively large movement at the [[electrical contacts]], which occurs at high speed (regardless of the speed of actuation). Switching happens reliably at specific and repeatable positions of the actuator, which is not necessarily true of other mechanisms. Most successful designs also exhibit [[hysteresis]], meaning that a small reversal of the actuator is insufficient to reverse the contacts; there must be a significant movement in the opposite direction. Both of these characteristics help to achieve a clean and reliable interruption to the switched circuit.

They are very common due to their low [[cost]] but high [[durability]], greater than 1 million cycles, and up to 10 million cycles for heavy-duty models.  This durability is a natural consequence of the design.

== History ==

The first micro switch was invented by [[Phillip Kenneth McGall]] in 1932 in [[Freeport, Illinois]], patent 1,960,020. McGall was an employee of the [[Burgess Battery Company]] at the time. In 1937 W.B. Schulte,<ref>((cite book|last1=Shouer|first1=Dick|title=Honeywell History|date=1 March 2015|publisher=Honeywell))</ref> McGall's employer, started the company MICRO SWITCH. The company and the ''Micro Switch'' [[trademark]] has been owned by Honeywell Sensing and Control since 1950.<ref>((Cite web|url=http://sensing.honeywell.com/1/4/6/5/6/1/index1.shtml|title=MICRO SWITCH Timeline - 1950s|last=|first=|date=|website=sensing.honeywell.com|url-status=dead|archive-url=https://web.archive.org/web/20110209015243/http://sensing.honeywell.com/1/4/6/5/6/1/index1.shtml|archive-date=February 9, 2011|access-date=2020-01-13))</ref> The name has become a [[generic trademark]] for any snap-action switch. Companies other than Honeywell now manufacture miniature snap-action switches.

== Construction and operation ==
[[file:Microswitch.jpg|thumb|The internals of a micro switch. Contacts, from left to right, are common, [[Switch#Contact terminology|normally open]], and [[Switch#Contact terminology|normally closed]].]]

In one type of microswitch,<ref>((Cite web|url=https://www.unionwells.com/micro-switch.html|title=Micro switch |last=Piter|first= Tiago|date=|website=www.unionwells.com|archive-url=https://web.archive.org/web/20200807123336/https://www.unionwells.com/micro-switch.html|archive-date=2020-08-07|access-date=2020-10-07))</ref> internally there are two conductive [[Spring (device)|springs]]. A long flat spring is hinged at one end of the switch (the left, in the photograph) and has electrical contacts on the other. A small curved spring, preloaded (i.e., compressed during assembly) so it attempts to extend itself (at the top, just right of center in the photo), is connected between the flat spring near the contacts and a fulcrum near the midpoint of the flat spring. An actuator nub presses on the flat spring near its hinge point.

Because the flat spring is anchored and strong in tension the curved spring cannot move it to the right. The curved spring presses, or pulls, the flat spring upward, that is away, from the anchor point. Owing to the geometry, the upward force is proportional to the displacement which decreases as the flat spring moves downward. (Actually, the force is proportional to the sine of the angle, which is approximately proportional to the angle [[Small-angle approximation|for small angles]].)

As the actuator depresses it flexes the flat spring while the curved spring keeps the electrical contacts touching. When the flat spring is flexed enough it will provide sufficient force to compress the curved spring and the contacts will begin to move.

As the flat spring moves downward the upward force of the curved spring reduces causing the motion to accelerate even in the absence of further movement of the actuator until the flat spring impacts the normally-open contact. Even though the flat spring unflexes as it moves downward, the switch is designed so the net effect is acceleration. This "over-center" action produces a very distinctive clicking sound and a very crisp feel.

In the actuated position the curved spring provides some upward force. If the actuator is released this will move the flat spring upward. As the flat spring moves, the force from the curved spring increases. This results in acceleration until the normally-closed contacts are hit. Just as in the downward direction, the switch is designed so that the curved spring is strong enough to move the contacts, even if the flat spring must flex, because the actuator does not move during the changeover.

== Applications ==

Microswitches have two main areas of application:

* Firstly, they are used when a low operating force with a clearly defined action is needed.
* Secondly, they are used when long-term reliability is needed. This is a result of the internal mechanism and the independence of the closing force on the switch contacts from the operating force. Switch reliability is largely a question of the contact force: a force that is reliably adequate, but never excessive, encourages long life.

Common applications of micro switches include the door [[Interlock (engineering)|interlock]] on a [[microwave oven]], leveling and safety switches in [[elevator]]s, [[vending machine]]s, [[Arcade game|arcade]] buttons, and to detect paper jams or other faults in photocopiers. Microswitches are commonly used in tamper switches on [[gate valve]]s on [[fire sprinkler system]]s and other [[Plumbing|water pipe]] systems, where it is necessary to know if a valve has been opened or shut.

Micro switches are very widely used; among their applications are [[Home appliance|appliances]], [[machine]]ry, industrial controls, [[vehicle]]s, [[convertible]] tops, and many other places for control of electrical circuits. They are usually rated to carry current in control circuits only, although some switches can be directly used to control small motors, [[solenoid]]s, lamps, or other devices. Special low-force versions can sense coins in vending machines, or with a vane attached, airflow. Microswitches may be directly operated by a mechanism, or maybe packaged as part of a [[pressure]], flow, or [[temperature]] switch, operated by a sensing mechanism such as a [[Bourdon tube]]. In these latter applications, the repeatability of the actuator position when switching happens is essential for long-term accuracy. A motor-driven cam (usually relatively slow-speed) and one or more micro switches form a timer mechanism. The snap-switch mechanism can be enclosed in a metal housing including actuating levers, plungers, or rollers, forming a [[limit switch]] useful for control of machine tools or electrically-driven machinery.

== See also ==

* [[Mercury switch]]
* [[Reed switch]]

== References ==

((refs))

==External links==
((commonscat|Microswitches))

* [https://web.archive.org/web/20100213093303/http://www.microswitch.com/ Honeywell celebrates the 75th anniversary of the Micro Switch]

((Switches))

[[Category:Switches]]

Pages transcluded onto the current version of this page (help):

Miniature snap-action switch (edit)
Template:Ambox (view source) (template editor protected)
Template:Cite book (view source) (protected)
Template:Cite web (view source) (protected)
Template:Commons category (view source) (template editor protected)
Template:Commonscat (view source) (template editor protected)
Template:Find sources mainspace (view source) (template editor protected)
Template:Hlist/styles.css (view source) (protected)
Template:Main other (view source) (protected)
Template:More citations needed (view source) (template editor protected)
Template:Navbox (view source) (template editor protected)
Template:Pagetype (view source) (protected)
Template:Plainlist/styles.css (view source) (protected)
Template:Reflist (view source) (protected)
Template:Reflist/styles.css (view source) (protected)
Template:Refs (view source) (semi-protected)
Template:Replace (view source) (protected)
Template:SDcat (view source) (protected)
Template:Short description (view source) (protected)
Template:Short description/lowercasecheck (view source) (protected)
Template:Side box (view source) (template editor protected)
Template:Sister project (view source) (template editor protected)
Template:Switches (edit)
Module:Arguments (view source) (protected)
Module:Category handler (view source) (protected)
Module:Category handler/blacklist (view source) (protected)
Module:Category handler/config (view source) (protected)
Module:Category handler/data (view source) (protected)
Module:Category handler/shared (view source) (protected)
Module:Check for unknown parameters (view source) (protected)
Module:Citation/CS1 (view source) (protected)
Module:Citation/CS1/COinS (view source) (protected)
Module:Citation/CS1/Configuration (view source) (protected)
Module:Citation/CS1/Date validation (view source) (protected)
Module:Citation/CS1/Identifiers (view source) (protected)
Module:Citation/CS1/Utilities (view source) (protected)
Module:Citation/CS1/Whitelist (view source) (protected)
Module:Citation/CS1/styles.css (view source) (protected)
Module:Disambiguation/templates (view source) (protected)
Module:Find sources (view source) (template editor protected)
Module:Find sources/config (view source) (template editor protected)
Module:Find sources/links (view source) (template editor protected)
Module:Find sources/templates/Find sources mainspace (view source) (template editor protected)
Module:Message box (view source) (protected)
Module:Message box/ambox.css (view source) (protected)
Module:Message box/configuration (view source) (protected)
Module:Namespace detect/config (view source) (protected)
Module:Namespace detect/data (view source) (protected)
Module:Navbar (view source) (protected)
Module:Navbar/configuration (view source) (protected)
Module:Navbar/styles.css (view source) (protected)
Module:Navbox (view source) (template editor protected)
Module:Navbox/configuration (view source) (template editor protected)
Module:Navbox/styles.css (view source) (template editor protected)
Module:Pagetype (view source) (protected)
Module:Pagetype/config (view source) (protected)
Module:Pagetype/disambiguation (view source) (protected)
Module:Pagetype/setindex (view source) (protected)
Module:Pagetype/softredirect (view source) (protected)
Module:SDcat (view source) (protected)
Module:Side box (view source) (template editor protected)
Module:Side box/styles.css (view source) (template editor protected)
Module:String (view source) (protected)
Module:Unsubst (view source) (protected)
Module:WikidataIB (view source) (template editor protected)
Module:WikidataIB/nolinks (view source) (template editor protected)
Module:WikidataIB/titleformats (view source) (template editor protected)
Module:Wikitext Parsing (view source) (protected)
Module:Yesno (view source) (protected)

Return to Miniature snap-action switch.

Retrieved from "https://en.wikipedia.org/wiki/Miniature_snap-action_switch"