SMK tall reed switches

SMK are known to have produced at least two types of reed keyboard switch. This page covers the older, tall type. The second known type is part of JM-0400 series.

The tall switch type was discovered in a Yaskawa keypad by Deepak Kandepet. These switches are illuminable, using the same type of lamp lead grips as with SMK JM-0400 illuminated, with which it bears a noticeable similarity. The two types appear to use identical keycaps on illuminated keys. Switches similar if not identical to the discovered examples can be seen in an SMK advertisement in Electronic Design advertisement from March 1974.

The switches have the old SMK diamond logo on both the top and bottom, making them readily identifiable as SMK products. JM-0400 by comparison is branded only on the bottom, making identification more difficult (especially with regard to the number of clone products that were on the market).

The reed switch type appears to support single pole plus illumination or double pole, but not both. There appears to be upstroke damping, but seemingly not downstroke damping.

Electrocraft sold the illuminated type—complete with lamp and keycap—as catalogue listing 35-456. Deepak Kandepet provided following photos of such a switch, although without the lamp fitted:

Deepak also provided the following photographs of one of the switches in the Yaskawa keypad. The keycap is again illuminable, although not used as such. The keypad is part of what appears to be a Yaskawa YASNAC CNC control panel.

Documentation

All material was scanned by Bitsavers unless otherwise noted.

• SMK advertisement, Electronic Design, Vol. 22 No. 6, March 15 1974