Previously, we explained that the feel of Alps Alpine TACT Switch™ products is broadly divided into sharp feel and soft feel – models with a short travel produce a sharp feel, whereas long-stroke types result in a soft feel. In this article, we introduce the middle-stroke type of TACT Switch™.
View the previous article here.
What is a Middle-Stroke TACT Switch™?
In the context of Alps Alpine's TACT Switch™ lineup, a short stroke (travel) is roughly between 0.1 and 0.3mm, while a long stroke indicates a travel of 1mm or more. A travel somewhere in the middle, between 0.4 and 0.9mm, is a what we call a "middle stroke."
TACT Switch™ Structures and Over-travel
Before explaining the structure of a middle-stroke TACT Switch™, let us look at the structures of short- and long-stroke types.
Structure of a Short-Stroke TACT Switch™
The travel of a short-stroke type TACT Switch™ is basically restricted to the stroke of the metal dome (moving contact).
For that reason, there is no over-travel after the contact closes. And the stroke tends to be shorter with a metal dome of smaller diameter.
Structure of a Long-Stroke TACT Switch™
The travel of a long-stroke type TACT Switch™ is the stroke of the rubber spring plus the compression of the rubber.
This rubber compression creates an over-travel after the contact closes. The softer the rubber (the lower its hardness), the longer the over-travel.
Structure of a Middle-Stroke TACT Switch™
A middle stroke is a mix between the above short and long strokes.
A rubber stem is used to press a metal dome. Even after the contact closes, the rubber flexes, creating over-travel.
By adjusting the hardness of the rubber, it is possible to retain the sharp feel of the metal dome while the additional over-travel alters the overall push feel.
Middle-Stroke TACT Switch™ Lineup
Alps Alpine currently supplies the following middle-stroke TACT Switch™ varieties.
Compact middle stroke type
realizing a clear operating feel.
Middle stroke type realizing low
operation sound and a clear
operating feel.
Compact and quiet middle
stroke type.
Switch with 0.9mm stroke
realizing a refined operating
feel.
Rubber stem helps to achieve
travel of 0.3 to 0.55mm & over
travel.
In this article, we explained the structure of a middle-stroke TACT Switch™. Next time, we will look at the kinds of feel and operating sounds that this structure can create.