EC Switch Explorer — Inside the Topre Switch

A working cross-section of a Topre electrostatic capacitive switch — assembly per Topre's silencing patent JP2012-138254A, cross-section geometry traced 1:1 from our SolidWorks assemblies, force curves from real domes measured in our lab. Press it with the button or the depth slider, hold Space — or grab the keycap, slider, dome, or spring and drag it. Click any part to learn its job.

Slider

Dome (Topre)

Force curves are our bench measurements of real Topre domes, not idealized models.

Silencing ring

0.50 mm — absurd thicknesses allowed. Try one and watch what breaks.

Rides on top of the plunger, around its keycap tube — it lands on the housing's upper stop wall on the upstroke.

Actuation point (APC)

Classic boards ship fixed; Realforce APC boards let you choose. Either way it's a capacitance threshold — nothing mechanical changes.

Parts — click to inspect

Keycap
Housing
Slider
Steel plate
Silencing ring
Rubber dome (cup rubber)
Conical spring
PCB + sensor pads

hold Space Depth 0.00 mm

Live readings

Finger force— g

Dome compression— mm

Travel available— mm

Collapse at— mm

Actuates at— mm

Capacitance (illustrative)— pF

restthreshold ▲max

NOT ACTUATED

Force curve — live

Grey: the dome's full measured curve. Shaded: stroke consumed by ring preload before your finger arrives. The dot is where you are.