RAFI RS 76 C
|Family||RAFI full-travel key switch|
|Sense method||Hall effect|
100 M (momentary)|
100 k (latching)
|Total travel||4 mm|
|Keycap mount||RAFI mount|
|Switch mount||PCB mount|
RS 76 C switches use a Hall sensor IC, actuated using a small magnet; the magnet is 2 mm wide, 3 mm tall and 1 mm deep. The magnet fits into a pocket within the slider. The IC provides the switch with four legs; an additional dummy leg is placed at the opposite end of the switch simply to help secure the switch. The momentary switches are damped on the downstroke by a rubber ring placed around the slider guide shaft; this is omitted from the illuminated and latching versions as it would partially block the holes in the base for the LEDs.
The momentary versions typically use yellow sliders, although in the 2016 catalogue they are shown with the same colourless slider as used by the illuminated and latching versions. The Siemens Teleperm ST215 does indeed uses colourless sliders. An anomalous version with a cream slider is depicted below.
The RAFI Electromechanical Components 2001 catalogue provides part numbers for IP 40 and IP 65–rated switches; at present, only IP 40–rated switches are listed in RAFI catalogues. The separate part numbers for different LED colours are also no longer listed.
RS 76 C should not be confused with low-profile ITW magnetic valve switches, which are also open-top and use a very similar keycap mount.
The series appears to be divided as follows:
- 3.13.001.nnnn — IP40
- 3.13.011.nnnn — IP65
The RAFI Electromechanical Components 2001 catalogue also lists the following dedicated part numbers for the illuminated versions:
|Action||IP rating||LED colour||Part number|
RS 76 C from the side, in an older RAFI B6-C keyboard
Sample received from RAFI in 2016.
Sample received from RAFI in 2016. This is identical to 010 except for having a heavier spring:
Anomalous cream version
- Electronic Design 25 (1976), Nr. 22, p. 102: A new switching technique for keyboard system RS 76 uses a Hall-effect IC to ensure that switching is bouncefree and reliable.
- Deskthority — Siemens Teleperm ST215