Micro Switch SD Series
|This article requires restructuring — the content relating to SW and SN series needs moving to the respective pages; also, this page is chaotic; also, use of a regular expression for model numbering is pretty brutal (now we have two problems ......)|
|This article requires additional photographic illustration — family portrait for infobox; dedicated variants table images|
Please be aware that the material on this page is unverified and may not be correct:
known variants list is almost entirely redlinks!
Everett A. Vorthmann|
Joeseph T. Maupin
|Supersedes||Micro Switch SW Series|
|Switch type||Linear, Tactile|
|Sense method||Hall effect|
Tested up to 30 billion|
|Peak force||45 g to 320 g[Citation needed]|
These switches are among the highest quality ever produced by any keyboard switch company, with reliability being paramount to their design. For increased reliability, there are both 3 pin and 4 pin designs of the switch. The 4 pin are +5, GND and dual open-collector outputs, allowing wired-or of the X, Y keyboard matrix. These switches are naturally bounce-free!
The last accessible reference to SN and SD series on the Honeywell website is from the 22nd of February 1999. The products list at this time were:
- Hall-Effect Keyboards Sales Sheet (02509_a.pdf)
- SD16 Keyswitch Modules Product Sheet (02503_0.pdf)
- 63SD30-4 Microcomputer-based Keyboard Product Sheet (02504_0.pdf)
- 26SD1-2 Point-of-Sale Keyboard Product Sheet (02506_0.pdf)
- 12SD/16SD Numeric Keyboards Product Sheet (02607_0.pdf)
The PDF documents were not archived. Later that year, Honeywell redesigned their website such that it could no longer be crawled (product data was accessible through form submission), so it is not clear when SD and SN series were phased out.
Features (as per Honeywell)
Details for switch Model 4A3A which should be consistent across all models, except for operating force:
- Total Travel - 0.160 in (4.1 mm) nom.
- Force at operating point - 2.8 oz. (78 g) nom.
- Pretravel - 0.090 in. (2.3 mm) nom.
- Release point at 5 VDC and 75°F (24°C) (With respect to free position) - 0.040 in. (1.0 mm) min.
Note that according to the 1998 1001SD Series Chart 2 (listed within Micro Switch SD16 Keyswitch Modules, below) this should be 0.695 N/2.5 oz, so the specifications may have changed over time.
Linear switch, much smoother and consistent in feel than Cherry MX Black switches for example.
There are 26 confirmed variants of the switch, probably more unknown variants exist. For a detailed view of the inside of these switches please refer to dorkvader's Hall Effect Switch Compendium linked at the bottom of this page under the external links.
Micro Switch and Honeywell switches typically have the series name within the part number, which was apparently notably not the case for SD Series. According to the 1998 1001SD Series Chart 2, the part numbers are are of the form 1001SDnnnn, where the four-character "identification code" is all that is printed on the switch, for brevity.
As a regular expression, the models can be shown as shown below. Descriptions given in italics are observations not corroborated with Micro Switch documentation.
According to the datasheet, "sloped" switches have upright stems: the description refers to how a tilted keyboard the keycap top surfaces will be sloped. Angled stem switches are called "stepped" due to the presentation of a staircase profile in a tilted keyboard.
- ([A-Z])? Sensor variant? (All sensor PCBs with this code have this printed on it)
- D - ?
- Q - ?
- R - ?
- T - ?
- ([0-9]+) Switch variant
- 1 - Unknown (white stem)
- 4 - Momentary action (black stem)
- 5 - Alternate action (black stem)
- 6 - Support (short black stem)
- 11 - Black stem, tactile
- 12 - LED keycap stem
- 16 - Alternate keyboard mount
- ([A-Z]) Stem type
- A - Sloped (non-angled)
- B - Stepped (angled)
- F - No keycap stem
- G - Flat top
- H - Flat-stepped
- K - Narrow bar stem
- S - Sloped
- T - Stepped (ridged housing)
- ([0-9]) Switch weighting (hard to read in the datasheet; some figures are best guesses)
- 1 - 0.362 N/1.1 oz
- 2 - 0.556 N/2.0 oz
- 3 - 0.695 N/2.5 oz
- 5 - 0.973 N/3.5 oz
- 6 - 1.668 N/6.0 oz
- 8 - 2.224 N/8.0 oz
- 4 - No spring (use with three unit button)
- ([A-Z]) Switch output
- A - Sink level (4 pins, 2 redundant sense lines)
- B - Sink pulse
- C - Source level
- E - 3 pins, 1 sense line
- K - Timed repeat (4 pins, 2 redundant sense lines)
- S - Logic scan (4 pins, 2 redundant sense lines)
- D - None
Confirmed variants of the switch:
- 1A3B - Micro Switch 68SD15-1-E
- 1A3S - TI Telex 58SD17-2-B
- 1A8S - TI Telex 58SD17-2-B
- 1B3S - Nokia MikroMikko 1 keyboard
- 1F5A - UGC-74 Keyboard
- 1K3S - Bunker Ramo ADMIN 20211322
- D1K3S - Bunker Ramo ADMIN 20403025
- 2K3S - Bunker Ramo ADMIN 20403025
- 4A1A - Honeywell 26SD1-2-H
- 4A1E - Burroughs TP110, Burroughs TP130
- T4A2B - Wang 271-1126 (Meaning of T is unknown)
- 4A2K - Wang 271-1126
- 4A3A - Bud Keypad 83959, Honeywell 26SD1-2-H
- Q4A3B - Wang 271-1126 (Meaning of Q is unknown)
- 4A3E - Burroughs TP110
- R4A3E - Burroughs TP130 (Meaning of the R is unknown)
- 4A8E - Burroughs TP110, Burroughs TP130
- 4B1D - Convergent 64-00164, Telex 278
- 4B1E - Space-cadet, Telex 278
- 4B1S - Convergent 64-00164
- 4B3E - Symbolics 3600 Rev D, Space-cadet, Telex 278
- 4B3K - Wang 271-1126
- 4B3S - Intergraph 2710
- 4T3S - Convergent 64-00164
- 5A3E - Burroughs TP110, Burroughs TP130
- 6A1D - Convergent 64-00164, Burroughs TP110, Burroughs TP130
- 6B1D - Convergent 64-00164, Space-cadet, Honeywell 26SD1-2-H, Telex 278
- 12B3S - Convergent 64-00164
- 16B3E - Sun 32SD38-4-E
SD Series appears to have gone out of production around 1999 or 2000. Keyboards with the switches do show up occasionally on auction sites like Ebay, but this isn't always obvious, and they most certainly don't work with modern computers without a converter. The last known keyboard with these switches was made in mid 1996 for Sun Microsystems. Further research has shown that Honeywell has been using their "dual magnet" design to make backlit switches for industrial keyboards as recently as 1999.[Citation needed]
Controller sensing characteristics
- dork_vader_exe — Hall Effect Switch Compendium switches Retrieved 2016-02-14.
- dork_vader_exe — Hall Effect Switch Compendium keycaps Retrieved 2016-02-14.
- Google — Honeywell Keypad Datasheet Retrieved 2015-07-27.
- MouseFan — SUN 32SD38-4-E USA — Last known manufactured Honeywell Hall Effect switch (Japanese only). Last updated 2004-05-02. Retrieved 2015-07-27.
- Honeywell.com — Technical document on Honeywell Hall Effect switches Retrieved 2015-07-27.