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FR Electronics RSM reed switches

FR Electronics made a variety of reed switches for computer keyboards. Little in the way of details has ever been recovered.



RSM 60/RSM62

RSM 60 was FR Electronics’ older reed keyboard switch series. In 1971, RSM 60 was described somewhere within Electronic Components volume 12 issues 1–6 (on page “580”) as having “Spst and dpst contact configurations … available as standard.” It appears that no further details were offered at the time. In later occurrences (by 1976) the series was referred to simply as “RSM62”; there is presently no information to indicate whether a heavier weight RSM63 existed in the same manner as RSM82’s RSM83 counterpart.

RSM62 has never been observed. RSM62 and RSM82 were described together in an advertisement in Electronics Today International, June 1983 page 65:

Keypad and keyboard range

FR Electronics manufacture a range of keyswitch products which use the RSM62 and RSM82 reed switch type keyboard switches.

It is claimed that the reed switches offer long electrical life and high reliability with a maximum of flexibility. The anti-rotational four-bearing plunger design is used to minimise sideplay and give smooth action. Illuminated and non-illuminated versions are available with single pole or double pole normally open functions. A full range of coloured keytops is available and alternative characters can be supplied on request.

Known models are:

Model Description Source
RSM62-1A SPST-NO momentary ICLocator.com (unconfirmed)
RSM-62-1AL SPST-NO momentary illuminated Eisenbahntechnische Rundschau†, Volume 21, 1972 (reported as new)
RSM-62-2-AL DPST-NO momentary illuminated
RSM62-1AL/28V LAMP SPST-NO momentary illuminated, 28 V lamp ICLocator.com (unconfirmed)
RSM 62/22A DPST-NO momentary Quantitative Methods in Biology‡, 1977

Sources marked † are from Google Books where only tiny fragments of the material can be seen, and the exact magazine or journal issue is not declared due to improper archiving. (‡ denotes that all relevant information is nonetheless visible.)


RSM82 is the low-profile replacement for RSM 60/RSM62. It was advertised in 1977 as being 0.7″ tall including the plunger, but RSM82-1A measures 0.89″ instead. The advertisement in Wireless World, March 1977 (page 82, PDF page 84) reads:

Keyboard switch

The RSM82 series is a range of low profile keyboard switches which utilize reed switches for reliability. Single pole and double pole switches are available, with or without latching, and an illuminated version may also be obtained. Each unit is designed for p.c.b. mounting and is 0.7in high from the top of the plunger to the base. A large range of button tops, space bars and mechanisms is also available.

The following passage appears in the article Keyboards, keyswitches and interface devices, Electronics Industry, volume 4, January 1978, of which a tiny fragment is readable on Google Books:

F.R. Electronics are another company with an established reed keyswitch line (their RSM62) who have more recently developed a low-profile version. The RSM82 appears to be the lowest profile reed keyswitch available with a body depth of only 13.5mm (less than half the depth of …

Model RSM82 1AX was rated for a maximum load of 15 VA.

Known models are:

Model Description Source
RSM82-1A SPST-NO momentary Acquired parts
RSM82 1AX SPST-NO alternate action Engineering†, Volume 216, 1976
RSM82 2AX DPST-NO alternate action ICLocator.com (unconfirmed)
RSM83-1A SPST-NO momentary, higher weight Observed parts
RSM83-1AL SPST-NO momentary illuminated with 5 V lamp (likely higher weight) Everyday Electronics, 1990

Sources marked † are from Google Books where only tiny fragments of the material can be seen, and the exact magazine or journal issue is not declared due to improper archiving.

Unitra Dolam M-24-112 is largely the same design, and one series will be based on the other.

Production of RSM82 was transferred to RRE of India, and the series name was changed to RKS 80. RKS 80 has since been discontinued.