Micro Switch SW Series
 | |
| Manufacturer | Micro Switch |
|---|---|
| Introduced | ca. 1968 |
| Precedes | Micro Switch SD Series |
| Supersedes | Micro Switch magnetic reed |
| Switch type | Linear |
| Sense method | Hall effect |
| Keycap mount | Micro Switch |
| Switch mount | Metal clips |
| Patents | US3596114 (1969) |
Micro Switch SW Series (formerly referred to as First Generation Dual Magnet Honeywell Hall Effect) is a series of Hall effect keyboards and switches from Micro Switch.
Nomenclature[edit | edit source]
The series name of "SW" is not 100% confirmed, but considering observed Micro Switch naming practice, the series name is likely to be correct, referring to both the keyboards and the switches. An eBay auction for NOS 1SW52-R red slider, angled keystem switches from 1987 contains a leaflet titled "Instruction Sheet SOLID STATE SWITCH MODULE REPLACEMENT" (MICRO SWITCH PK 8503 2),<ref name="friendly-name" /> offering the possibility that the series name was not always used; with that said, at that point it was not the only Hall effect switch available from Micro Switch.
History[edit | edit source]
According to Micro Switch, they introduced the "world's first solid-state keyboard" in 1968.<ref name="history" /> A patent was filed for the series in November 1969.
Based on the keyboard examples listed below, the known production range for SW series keyboards is 1970–1980. A similar list of examples isn't available for Micro Switch SD Series but it is likely that SW series was superseded by SD series somewhere around 1980.
SW series appears to have been followed by Micro Switch SN Series; comparing the Micro Switch SN/SD Series catalogue page with the switches sold by STRONIC in France appears to show three separate designs: SW, SN as depicted by Micro Switch, and SN as sold. One consistent difference between SW and SN is that the bottom of the shell in SN is not stepped as it is with SW; the retaining loop system is a different design and the shell sides are vertical at the base.
Components and durability[edit | edit source]
Hall Effect switches consist of a slider (with integrated magnets and spring), the switch housing (which is much harder than the slider -- this causes wear), and metal clips that act a plate to secure the switches. The metal clips determine what layouts are possible.Some Hall Effect switches are fully sealed against dust/debris to prevent dust from interfering with the capacitive matrix since a dirty PCB can affect switch sensing. Unsealed switches will function in bad conditions, but their press feel will be degraded due to grit.
Variants[edit | edit source]
| Part no. | Colour | Angle | Found in |
|---|---|---|---|
| 1SW12-BL | Black | Straight | IBM 3277 typewriter keyboard (1972) |
| 1SW52-R | Red | Angled | NOS (1987) |
| ? | Blue | ? | ? |
| ? | Green | ? | ? |
| ? | Grey | ? | ? |
Removal and disassembly[edit | edit source]
You can remove a switch housing from a Hall sensor by bending its metal clips out a little (switches have a channel in them for a screwdriver). The disassembly process is relatively simple, making maintenance and cleaning easy. For reattaching the springs to the slider use the "chopstick" method; Twisting the spring one direction will tighten the spring twisting the other will open the end up a little. Twist to open the end and lightly push it in place.
Gallery[edit | edit source]
-
Micro Switch Hall Effect switches mounted in metal clips -
Top view of sensors and clips on plate -
Switch parts: magnetic contact, gold spring and housing -
Switch parts (another view) -
An assembled switch -
Mounted switches -
Switch parts (another view) -
Box housing -
Slider and spring
Keyboards[edit | edit source]
- Decision Data 8010 punchcard keyboard (1974)<ref name="DD-8010" />
- Honeywell 81SW11-1 keyboard module<ref name="SW81"/> (black, straight stem, 1973)
- IBM 3275/3277 Display Station Keyboard (black, straight stem, 1972)
- NCR K5-CE-69-SFJ-S4 (black, straight stem, 1974)<ref name="NCR"/>
- Texas Instruments TI Silent 700 Model 732/733 keyboard (Part #: 959327-0001/0003)<ref name="randomvariations"/>
References[edit | edit source]
<references> <ref name="friendly-name">eBay — LOT OF 2 - Honeywell Microswitch 1SW52-R Solid State Switch Module replacement[Volatile reference]</ref> <ref name="history">Internet Archive Wayback Machine — History (archived 1999-04-22)</ref> <ref name="DD-8010">Flickr — Decision Data 8010 Punchcard Keyboard</ref> <ref name="randomvariations">randomvariations USING A TI SILENT 700 MODEL 733 KEYBOARD WITH AN APPLE 1 COMPUTER Posted 2014-10-16.</ref> <ref name="NCR">Deskthority — NCR K5-CE-69-SFJ-S4 Keyboard Posted 2022-05-18.</ref> <ref name="SW81">Deskthority — Ortholinear Micro Switch SW 81SW11-1 Posted 2022-07-07.</ref> </references>
External links[edit | edit source]
- Deskthority — Custom Hall Effect Switch Keyboard (1980)
- Deskthority — 1977 Micro Switch keyboard
- Deskthority — Micro Switch SW-10591 teardown (1976)
- Deskthority — Micro Switch SW-10876 review (1978)
- dork_vader_exe — Microswitch 56SW5-2 (1975 or 1977)
- dork_vader_exe — Microswitch 64SW1-10 (1977)
- HaaTa — Micro Switch 64SW1-4 (1970)
- Honeywell Sensing — Hall Effect Sensing and Application PDF
