Elec-Trol
Elec-Trol was a manufacturer of reed switches, reed and solid state relays, coils, keyboards and gauges (from the list of NSNs found at PartTarget). The Procure International website briefly mentions that Elec-Trol were acquired by Hamlin (another reed manufacturer), and Hamlin were in turn acquired by Littelfuse in 2013. (Littelfuse also acquired IXYS in 2018, who in turn acquired Clare.)
Contents
Datakeys
Elec-Trol’s line of keyboard switches were called “DATAKEYS”, also described as “Snap-Lock DATAKEYS”. Details on these reed switches are all but nonexistent. They are broadly cylindrical in design (a form also taken by Clare-Pendar Series S830 and GRI Series KB amongst others) around 16.3 mm in diameter at the widest part, with a shell 30.5 mm tall. The plunger is around 12 mm tall and, in most discovered examples, has a small cruciform mount.
Elec-Trol promoted the feature of being able to plate-mount the switches, which was a fairly novel idea in 1970 when they were advertised. Around half of the switch is above the plate when so mounted. Curiously, the only keyboard known to use them, has no mounting plate, and looking at the PCB, there seems to be nothing else securing the switches (no dummy terminal or fixing screw).
The following models are known:
| Model | Configuration | Travel | Terminals | Source | NSN |
|---|---|---|---|---|---|
| KA1001-0004 | SPST-NC double break, “with contact on arm” | NSN | 5930-00-160-5781 | ||
| KA1002-0014 | NSN | 5930-00-160-5848 | |||
| KA1003-0004 | SPST-NO momentary, 250 V AC/DC maximum | NSN | 5930-00-160-5853 | ||
| KA1004-0001 | Single pole momentary; hollow plunger that accepts adapter | Pertec keyboard | |||
| KA1005-0001 | NSN | 5930-01-085-4574 | |||
| KA1005-0001TC204 | SPST-NO momentary, 0.112″ thread | NSN | 5930-01-055-7852 | ||
| KA1011-0017 | SPST-NO momentary | 5 mm | Positions 1 and 3 | Own collection | |
| KA1012-0009 | NSN | 5930-01-013-0253 | |||
| KA1016-0009 | NSN | 5930-01-027-2834 | |||
| KA1017-0004 | SPST-NO momentary | Positions 1 and 2 | Andrew Nelsen |
KA1017-0004 is reported as having 0.27″ travel, which would give 6.9 mm, but this seems at odds with the plunger dimensions, which (from a brief video depicting the switch) would suggest 5 mm travel the same as KA1011-0017 as the plunger dimensions appear to be the same.
At least two keycap models are known, TA1-03-0-0000 (NSN 5930-01-027-9709) and TA1-04-0-0000 (NSN 5815-01-014-5692). As no markings are listed for either, they may simply be blank (as the model numbers themselves suggest, with 03 and 04 possibly designating the colours). TA60100000 (NSN 5895-00-499-8542) is given as “BAR,SPACER” and thus would seem to be a space bar keycap, of unspecified dimensions.
Two keyboards are known. Model KB1033-0000 is known only from its NSN designation of 5840-01-030-5544. There is also a Pertec keyboard, which is the source of switch model KA1004-0001 (assuming that it can be read correctly from the photos). The switches in the “Pertec” keyboard appear to be marked as having been manufactured in 1973, which matches the IC dates.
The photos below, provided by Andrew Nelsen, depict model KA1017-0004.
Documentation
- Elec-Trol Snap-Lock Datakeys advertisement, Computer Design, March 1970, page 61 (scanned by Bitsavers)
- Elec-Trol switches and keyboards advertisement, Computer Design, March 1970, page 122 (scanned by Bitsavers)