deskthority

So, I'm working on a compilation of data and was wondering if anyone could point me in the right direction! For one of my projects at school, I've taken it upon myself to try and make things interesting and make my project about keyboards. The gist is: does actuation force increase/decrease over time. Anyway, that's besides the point:

I was wondering if anyone could point me in the direction of catalogues/sources that include actuation force of some kind? Something citeable, like a patent or a physical magazine. I think it would be pretty useful not only for me but also the Wiki if I manage to find a few. Of course I could just restrict testing to the meager few switches I have on hand, but I digress. Any help would be much appreciated! Thanks!

Have you looked around the wiki? Where known, actuation forces are recorded, and where available, historical literature has been uploaded.

The difficult aspect with reading product literature is that the details are often vague, incomplete or misleading. The term "operating force" can mean both the actuation force, and the force at total travel. Quite often, you have to guess what is meant from the specification. With Omron B3G-S, interpreting the data has proved particularly tricky.

The wiki does not provide data mining however; if it existed, you could start by looking up which switches have this data recorded at all.

One of my own questions is, what happens to a switch at the end of its rated lifetime?

Daniel Beardsmore wrote: One of my own questions is, what happens to a switch at the end of its rated lifetime?

All those clicks will be lost in time, like tears in rain.

I preferred the book ;-)

I put the data I encountered here: [wiki]Switch lifetime[/wiki]. What this doesn't say, however, is whether the life-end thresholds are those where the switch is unsuitable for use (i.e. the thresholds define the lifetime), or whether they're simply noting what the switch will be like when, for some other reason, it is deemed to be end-of-life.

Bladed Runner was a book? Oo

The user HaaTa here has a force/displacement-measuring device and has measured and plotted force graphs for quite a few switches. Here you can see his force-graphs of actual switch specimens. The actuation and reset points are plotted, so you can get the force and travel at those points.
Note that these are only single specimens though, and individual switches can vary. Some hardware sites (e.g. Anandtech.com) when they review keyboards also test keyboard actuation force on each key and show the variance.

HaaTa's graphs are also interesting in how they sometimes differ from manufacturers' official graphs - the latter are often quite idealised where as real graphs show how scratchy the switches actually are. In a few cases they also reveal bumps and dips that are not in the manufacturers' graphs at all.

Chyros wrote: Bladed Runner was a book? Oo

"Do Androids Dream of Electric Sheep", by Philip K. Dick. It is different from the film in several ways: for instance, Deckard is definitely a human and the replicants are robotic, not organic.