Editing SMK Discrete Dome

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{{infobox dswitch
| image name          = 
| manufacturer        = [[SMK]] 
| product code        = 
| contact mechanism   = Conductive dome, Membrane
| switch type         = Clicky, Tactile
| force               = 
| introduced          = 
| discontinued        = 
| switch mount        = [[Plate mount]]
| keycap mount        = SMK two-prong <!--, [[keycap mount#Custom cruciform|SMK inverse cross mount]]-->, 
}}
'''SMK discrete dome''' is a name given to a line of switches produced by [[SMK]]. It appears to be similar in concept to [[Alps integrated dome]], except the contacts are either on the PCB or on a membrane sheet, rather than being contained within the switch module. A miniaturized version exists for use with small keys.<ref name="dt-canon-s51" /> 

==Description==
All observed examples of the clicky variety have a pair of conductive traces on the PCB for each key, above which the switch is clipped into the metal switchplate. The bottom housing of the switch sits flush with the PCB and there is a circular opening in the middle of the bottom housing. Inside the switch there is a rubber dome with a conductive pad on the underside that presses through the opening in the housing and onto the PCB to bridge the traces. Over the dome there is a spring and click jacket and over that there is a slider clipped into the bottom housing.
The tactile version of the switch deviates from the clicky version in that it is situated above a membrane instead of a PCB, it does not have a conductive pad on the underside of the dome and instead has a non-conductive nub that presses on the membrane, and there is no spring between the dome and the slider.<ref name="Sony KI-9700 review (SMK spring-over-dome)"/> There is no functional reason that the clicky and tactile versions use different contact types but no clicky membrane or tactile PCB have presently been identified.

The slider is notably large, covering most of the area of the switch. The switch bears a passing visual resemblance to [[Omron B3K series]] switches, and to a lesser extent, [[Alps SKCP series]].

Like other [[:Category:Spring over dome switches|spring-over-dome]] switches, such as [[Fujitsu Peerless]], the switch is linear until a distinct tactile/actuation event near the bottom.
Unlike the Peerless, however, it is very smooth and wider keys are fully [[Stabiliser|stabilised]]. The switches have been noted to be more tactile, and in the case of the clicky version, louder in a disassembled keyboard.<ref name="youtube-disassembly" />

==Variants==
===Two-prong mount===
The keycap mount consists of a pair of holes: north and south on the slider, for two prongs on the inside of the keycap.

<!--
Awaits confirmation that it is the same mechanism, and not just looks the same apart from the keycap mount.

==SMK inverse-cross mount==
The same inverse cross-mount such as [[SMK inverse cross mount|SMK inverse cross mount mechanical]] has been observed.<ref name="mhinsch-CanonAP6300" />
<ref name="mhinsch-CanonAP6300">Deskthority — [https://deskthority.net/viewtopic.php?f=58&t=17573&start= &#91;WTT&#93; SMK inverse cross keycaps, switches, Canon AP 6300 typewriter]</ref>
-->

==Related switches==
There is also a miniaturised switch for use with smaller-sized keys. This appears to be similar in design to the full-sized version, but uses a different mount, with a cruciform shape.

Another switch which appears to be related to this and may be an additional variant has also been observed.<ref name="dt-sony-ki9700p" /> This features a grey-coloured slider with a different pattern. The keycap mount is the same as the normal full-size version.

==Keyboards==

*Various [[Canon]] typewriters, including the S-51<ref name="dt-canon-s51" />, Typestar 5<ref name="imgur-canon-typestar-5" /> and Typestar 6<ref name="reddit-canon-typestar-6" /> (Keys with lock lights have a round window in the top left of the cap.)
*[[DataDesk]] PC 8700 JR/XT<ref name="GH-DataDeskPC8700" />
*Sony KI-9700P keyboard contains the tactile variant<ref name="Sony KI-9700 review (SMK spring-over-dome)"/>

==References==
<references>
<ref name="dt-canon-s51">Deskthority - [https://deskthority.net/viewtopic.php?t=19859 Canon S-51 typewriter (SMK "peerless"?)]</ref>
<ref name="imgur-canon-typestar-5">Imgur - [https://imgur.com/gallery/aq7sG What switch is this? Canon Typestar 5]</ref>
<ref name="reddit-canon-typestar-6">Reddit - [https://old.reddit.com/r/MechanicalKeyboards/comments/6zk5vs/so_i_just_found_this_machine_and_im_not_sure_what/ So I just found this machine and I'm not sure what switch is it. Is it just a rubber dome?]</ref>
<ref name="dt-sony-ki9700p">Deskthority - [https://deskthority.net/viewtopic.php?f=2&t=19976&start=60 IDENTIFY THE KEYSWITCH thread (page 3)]</ref>
<ref name="GH-DataDeskPC8700">Geekhack — [https://geekhack.org/index.php?topic=80898.0 DataDesk International PC 8700 (for IBM PCjr)]. Postged 2016-03-29. Retrieved 2019-05-05</ref>
<ref name="youtube-disassembly">YouTube - [https://www.youtube.com/watch?v=42fLdTLuYj0&t=43m55s Hjalfi opens a Canon TypeStar 4 thermal typewriter]</ref>
<ref name="Sony KI-9700 review (SMK spring-over-dome)">YouTube - [https://www.youtube.com/watch?v=ZkiE2AbrWWc Sony KI-9700 review (SMK spring-over-dome)]</ref>
</references>

[[Category:SMK switches]]
[[Category:Spring over dome switches]]
[[Category:Clicky switches]]
[[Category:List of all keyboard switches]]