Hardware Reference
In-Depth Information
Membrane keyswitches are not just relegated to fast food or industrial uses, though. The
membranekeyswitchusedwithconventionalkeyboardkeytopshasbecomethemostpop-
ular keyswitch used in low-cost to mid-range keyboards, and even some high-end units.
Although low-end membrane keyswitches have a limited life of only 5-10 million key-
strokes, some of the better models are rated to handle up to 20 million keystrokes, put-
ting them in the range of pure mechanical switches for durability (see
Figure 15.4
). A few
membrane switches are even more durable: Cherry Corporation's G8x-series keyboards
use Cherry's own 50-million-keystroke membrane switch design (
www.cherrycorp.com
).
Figure 15.4
A typical membrane keyswitch used in NMB keyboards.
Membrane keyboards typically provide a firmer touch than rubber dome keyboards or the
old foam-element keyboards, and those with buckling spring designs can provide the ul-
timate in tactile feedback. One interesting variation includes the line of keyboards made
by KeyTronicEMS using its center-bearing version of membrane keyswitches. Most of its
