Tokai MM9 series
|This article requires additional photographic illustration — clearer internals photos|
|Product code||MM9-1, MM9-2, MM9-3, MM9-4|
|Switch type||Progressive rate|
5 ms make, 10 ms break (MM9-1/2)|
10 ms (MM9-3/4)
|Peak force||100±30 g|
|Total travel||2.5±0.3 mm|
Tokai MM9-series is a novel switch design that uses an alloy metal ball as part of the contact mechanism. The exact operation of the switch remains unclear.
The switches were described by the Tokai website as 「接点が回転するボールコンタクトスイッチ！」. The implication of is not clear; it could be suggesting that the ball rotation spreads out the contact wear, but it may simply be a very brief explanation of the operation. The switches have a comparatively short lifetime of only two million cycles; there are no flexible parts in the contact mechanism, which may be related. The website also classified the switches as 「メカニカルスイッチ」, "mechanical switch".
Switch travel is 2.5±0.3 mm. 「作動力」, "actuating force", is given as 100±30 g. This is not the actuation force but rather the peak/terminal force. The switch is progressive rate; the perceived action is progressive rate with knee, but in reality there is an instantaneous jump of around 25 cN at the actuation point, from around 45 cN to nearly 70 cN. Actuation occurs at this point, followed by a stiff overtravel region up to the stated 100 g mark.
|Model||Switch mount||Keystem height|
|MM9-1||Plate mount with solder terminals||6 mm|
|MM9-2||Plate mount with solder terminals||4 mm|
|MM9-3||JIS C 2809 panel mount||4 mm|
|MM9-4||JIS C 2809 panel mount||6 mm|
- Uncertain numeric keypad (MM9-1)