RAFI RS 76 C

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RAFI RS 76 C

Manufacturer	RAFI
Family	RAFI full-travel key switch
Product code	3.13.001.nnn 3.13001.nnn 3.13011.nnn
Introduced	1976<ref name="Intro" />
Switch type	Linear, latching
Sense method	Hall effect
Rated lifetime	100 M (momentary) 100 k (latching)
Total travel	4 mm
Keycap mount	RAFI mount
Switch mount	PCB mount
Website	www.rafi.de/RS-76-Langhubtaster-zum-Aufbau.165.0.html

File:Brand logo--HFO (approximation).svg

HFO—VEB Halbleiterwerk Frankfurt (Oder)—logo found on the 76 C Hall IC

RAFI RS 76 C is a series of PCB-mount Hall effect switches in the RAFI full-travel key switch family.

Design

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.

Variants

The series appears to be divided as follows:

• 3.13.001.nnnn — IP40
• 3.13.011.nnnn — IP65

	Action	IP rating	Illuminated	Terminal force	Part number
	Momentary	IP 40	No	70 cN	3.13.001.010/0000 (2016) 3.13001.010 (2001)
	Momentary	IP 40	No	100 cN	3.13.001.210/0000 (2016) 3.13001.210 (2001)
File:No photograph.svg	Momentary	IP 65	No	100 cN	3.13011.010 (2001)
File:No photograph.svg	Momentary	IP 65	No	130 cN	3.13011.210 (2001)
	Momentary	IP 40	Yes	70 cN	3.13.001.110/0000 (2016) 3.13001.110/0000 (2001)
File:No photograph.svg	Momentary	IP 65	Yes	110 cN	3.13011.110/0000 (2001)
	Latching	IP 40	Yes	70 cN	3.13.001.130/0000 (2016) 3.13001.130/0000 (2001)
File:No photograph.svg	Latching	IP 65	Yes	110 cN	3.13011.130/0000 (2001)

The RAFI Electromechanical Components 2001 catalogue also lists the following dedicated part numbers for the illuminated versions:

Action	IP rating	LED colour	Part number
Momentary	IP 40	None	3.13001.110/0000
Momentary	IP 40	Red	3.13001.110/1350
Momentary	IP 40	Green	3.13001.110/1550
Momentary	IP 40	Yellow	3.13001.110/1450
Momentary	IP 65	None	3.13011.110/0000
Momentary	IP 65	Red	3.13011.110/1350
Momentary	IP 65	Green	3.13011.110/1550
Momentary	IP 65	Yellow	3.13011.110/1450
Latching	IP 40	None	3.13001.130/0000
Latching	IP 40	Red	3.13001.130/1350
Latching	IP 40	Green	3.13001.130/1550
Latching	IP 40	Yellow	3.13001.130/1450
Latching	IP 65	None	3.13011.130/0000
Latching	IP 65	Red	3.13011.130/1350
Latching	IP 65	Green	3.13011.130/1550
Latching	IP 65	Yellow	3.13011.130/1450

Keyboards

• RAFI B6-C
• RAFI B8-C
• RAFI 401.002.159
• Siemens Teleperm ST215 (white sliders)<ref name="DT-ST215" />

Gallery

• 
  RS 76 C from the side, in an older RAFI B6-C keyboard

3.13.001.010/0000

Sample received from RAFI in 2016.

• 
  Typical yellow RS 76 C, 70 cN version (3.13.001.010/0000)
• 
  Magnet partially removed from the slider
• 
  Redundant leg, held between a ramp and retaining steps
• 
  Fully disassembled, top views
• 
  Fully disassembled, bottom views

3.13.001.210/0000

Sample received from RAFI in 2016. This is identical to 010 except for having a heavier spring:

• 
  Spring comparison, 010 vs 210

Anomalous cream version

• 
  Anomalous cream RS 76 C switch
• 
  Bottom side of the switch; IC legs on the left hand side
• 
  Disassembled switch; the red line on the IC marks the border between the rest position and the activated position.
• 
  The RS 76 C slider has an extension with a pocket for the magnet.

References

<references> <ref name="Intro">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.</ref> <ref name="DT-ST215">Deskthority — Siemens Teleperm ST215</ref> </references>