Elec-Trol Inc. was a manufacturer of reed switches, reed and solid state relays, coils, keyboards and gauges (from the list of NSNs found at PartTarget). They appear to have been an early adopter of the idea of plate-mounted keyboard switches, with their Snap-Lock Datakeys range. They also produced printer model PR1021 that would print characters sideways.
Little is known about Elec-Trol. Advertisements in 1968 and 1970 give Elec-Trol’s address as 21018 Soledad Canyon Road, Saugus, California 91350. By 1985 they had moved to 26477 North Golden Valley Road, Saugus, zip code 91530.
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.)
Elec-Trol’s line of keyboard switches were called “DATAKEYS”, also described as “Snap-Lock DATAKEYS” and ‘“Snap-Lock” data keys’. 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).
A brief advertisment in EEE, Volume 18, 1970 reads:
Keyboard switches, Datakey, with up to 3 internal diodes for steering, encoding, MOS-logic address, DTL, TTL, MOS compatible. Keys snap into metal mounting plate. ELEC-TROL. 544
The following models are known:
|KA1001-0004||SPST-NC double break, “with contact on arm”||NSN||5930-00-160-5781|
|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||
TRS-80 Color Computer substitute keyboard
|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|
|KA1011-0018||SPST-NO momentary||Uncertain device|
|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.
The photos below, provided by Andrew Nelsen, depict model KA1017-0004.
Elec-Trol advertised MOS-encoded keyboards in The Electronic Engineer in November 1971. This advertisement contains a small photograph and few details.
One keyboard model has been found, KB1033-0000, known only from its NSN designation of 5840-01-030-5544.
A single Pertec keyboard has been found, with model KA1004-0001 switches (assuming that the switch part number 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. As the PCB is labelled “PERTEC” it is quite possible that Pertec made this keyboard themselves, but Elec-Trol could have produced it and labelled the PCB according to their customer’s requirements.
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.
All material below was scanned by Bitsavers unless otherwise noted.
- Elec-Trol Snap-Lock Datakeys advertisement, Computer Design, March 1970, page 61
- Elec-Trol switches and keyboards advertisement, Computer Design, March 1970, page 122
- MOS keyboards advertisement, The Electronic Engineer, Vol. 30 No. 11, November 1971