SMK Alps mount lock
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| Manufacturer | SMK |
|---|---|
| Family | SMK second generation |
| Switch type | Alternate action |
| Sense method | Metal leaf |
| Total travel | 3.5 mm |
| Keycap mount | Alps mount |
| Switch mount | Plate mount |
SMK Alps mount lock is the alternate action switch in the SMK second generation series.
Description
The operation is very similar to that of SMK lock, where a swivelling pin follows a track. Where the J-M0404 series version used an external module to house the pin and a track on the slider, the second generation design reverses this: the track is in a separate block, and the pin fits into the slider. The position of the track block inside the switch explains why the left-hand retention clip is offset to the back of the switch.
The pressure spring that supports the follower pin is small, at 4 mm long and 1.38 mm in diameter; this is larger than the equivalent spring in RAFI full-travel key switch, which in RS 74 M is a mere 2.7 mm long.
Keyboards
- Some Apple Keyboard II
- Some Apple Desktop Bus Keyboard
Gallery
Top; the mini PCB from the Keyboard II is still attached
Opened
Switch contacts; note that they are inverted as this switch needed repair
Follower pin, released
Follower pin, pressed in
Follower pin removed from the slider
Latch track block
Pressure spring length
Pressure spring diameter
Switch components
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