Table of Contents

Alps AKC

Alps AKC
A single desoldered Alps AKC switch
Manufacturer Alps Electric
Family Alps AKC
Part Number AKC or AKM
Switch Type Linear
Travel 3 - 3.5mm1)
Sense method Spring contact
Mount Plate mount
Rated lifetime 5 million cycles2)
Quoted operating force Unknown

Alps AKC switches, commonly referred to as “Alps spring bridge” are a mid-1970s series of Alps switches.

Characteristics

The switch consists of a stem with a metal rod through for attaching a keycap, and a recess in which a fine, gold-plated spring rests slightly deformed. As the stem is pushed, the spring brushes against and bridges the contacts3), which are tinned pads on a square chunk of PCB substrate. This PCB substrate passes through a slot on a key module's PCB and is bridged to it. Return force is provided externally, and care should be taken when removing keycaps (which have a strong grip) as flyaway springs are incredibly likely.

Several variations exist - the metal-topped version, as seen in the infobox, appears to be first. There was a later all-plastic version4). There also appears to have been a keyboard variant, based on the AKB-3000 series keyboard advertisement. This has a larger quoted travel than any instance of the switch seen so far so could have a differently sized housing.

The switch could also be ordered as a set module under part code “AKM”. This can often be seen in calculators.

Additional Information

The switch was likely in production from as early as 19735) to 19796). It was replaced by Alps SKCC Gray.

The switch could sometimes be seen with a mount adapter allowing for cruciform mount keycaps to be fitted.

1)
3mm measured on calculator switch, 3.5mm quoted in an AKC computer keyboard advertisement
3)
hence “spring bridge”
4)
to be added, seen in Olympia CD series calculators
5)
Alps AKB-3000 advertisement
6)
Earliest calculator sightings of SKCC Gray