RAFI RS 76 M
 | |
| Manufacturer | RAFI |
|---|---|
| Family | RAFI full-travel key switch |
| Introduced | 1975 |
| Switch type | Linear; progressive rate; latching action |
| Sense method | Metal contact |
| Bounce time |
5 ms 10 ms (illuminated) |
| Total travel | 4 mm |
| Keycap mount | RAFI mount |
| Switch mount | PCB mount |
RAFI RS 76 M is a series of metal contact switches in the RAFI full-travel key switch family. It is the mechanical counterpart to the Hall effect RS 76 C, and the 4 mm travel equivalent to RS 74 M. The series comprises standard, illuminated and latching action switches, with linear and progressive rate feel depending on design.
Design
All RS 76 M switches are open top; the diode versions do use a switch top but it leaves most of the internals exposed regardless.
The non-illuminated switches are crosspoint contact. The perimeter loop movable contact used in this design leaves no room for internal LEDs, so the illuminated versions of the switch instead use a "bridge" contact: this comprises a horizontal flat metal bar that is lowered by the slider onto a pair of stationary contacts, one on either side of the switch. To allow for overtravel, this bar sits below a spring, and once it reaches the stationary contacts the slider continues to move, with the spring above the bar being compressed. This gives the switch a progressive rate force curve, and the change in force is sharp enough that keys can be tapped light enough to actuate.
Variants
The RAFI Electromechanical Components 2001 catalogue provided 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.
The series appears to be divided as follows:
- 3.13.002.nnnn — IP40
- 3.13.012.nnnn — IP65
- 3.13.005.nnnn — with diode
| Sub-series | Action | IP rating | Terminal force | Part number | |
|---|---|---|---|---|---|
 |
RAFI RS 76 M (basic) | Momentary | IP 40 | 90 cN | 3.13.002.502/0000 (2016) 3.13002.502 (2001) |
 |
RAFI RS 76 M (basic) | Momentary | IP 40 | 140 cN | 3.13.002.512/0000 (2016) 3.13002.512 (2001) |
 |
RAFI RS 76 M (basic) | Momentary | IP 65 | 110 cN | 3.13012.502 (2001) |
|
RAFI RS 76 M (basic) | Momentary | IP 65 | 160 cN | 3.13012.512 (2001) |
 |
RAFI RS 76 M (diode) | Momentary | IP 40 | 90 cN | 3.13.005.001/0000 (2016) 3.13005.001 (2001) |
 |
RAFI RS 76 M (diode) | Momentary | IP 40 | 140 cN | 3.13.005.011/0000 (2016) 3.13005.011 (2001) |
|
RAFI RS 76 M (diode) | Momentary | IP 65 | 110 cN | 3.13012.001 (2001) |
|
RAFI RS 76 M (diode) | Momentary | IP 65 | 160 cN | 3.13012.011 (2001) |
 |
RAFI RS 76 M (illuminated) | Momentary | IP 40 | 100 cN | 3.13.002.102/0000 (2016) 3.13002.102/0000 (2001) |
|
RAFI RS 76 M (illuminated) | Momentary | IP 40 | 140 cN | 3.13.002.107/0000 (2001) |
 |
RAFI RS 76 M (illuminated) | Latching | IP 40 | 100 cN | 3.13.002.022/0000(2016) 3.13002.022/0000(2001) |
 |
RAFI RS 76 MX | Momentary | IP 40 | 100 cN | 3.13.002.922/0000 (2016) |
The RAFI Electromechanical Components 2001 catalogue also lists the following dedicated part numbers for the illuminated versions with LEDs fitted:
| Action | Terminal force | LED colour | Part number |
|---|---|---|---|
| Momentary | 100 cN | Red | 3.13002.102/1350 |
| Momentary | 100 cN | Yellow | 3.13002.102/1450 |
| Momentary | 100 cN | Green | 3.13002.102/1550 |
| Momentary | 140 cN | Red | 3.13002.107/1350 |
| Momentary | 140 cN | Yellow | 3.13002.107/1450 |
| Momentary | 140 cN | Green | 3.13002.107/1550 |
| Latching | 100 cN | Red | 3.13002.022/1350 |
| Latching | 100 cN | Yellow | 3.13002.022/1450 |
| Latching | 100 cN | Green | 3.13002.022/1550 |
