Electronic Supply sites make me cry (A switch-related question)

[jla2125]

Electronic Supply sites make me cry :( (A switch-related question)

Ok so I've been going through Newark's site, trying my darnedest to find a tactile switch that A: does what I want, and B: has plastic switch caps of some kind that fit.

To address item A, I need a tactile button that is normally closed, and that when I press it, it closes. When I release it, it opens again. The options I'm given are things like "Off-(On)", and "Off-On", and various permutations and parenthisizations thereof. Can you guys maybe clear up what all the weird options are, cause no company seems to want to tell me straight-up...

Now for option B: all I want is to be able to put some kinda nice cap on it, maybe a cylindrical one, but really, I just want it to not hurt when I press it.

Why are the datasheets for these things just mechanical drawings and not like, opperating specs? And why don't they tell me what other switch-related parts they work with? For a real engineer, does it really take 1 hour to look for a simple tactile switch, and fail?

 

[MATLABdude]

I find that DigiKey has the nicest sorting features out of the suppliers I frequent (they also usually have datasheets available). Maybe it's the fact that I grew up in the age of paper, but I like having a paper catalogue, as classes of things are usually grouped together, and more explanatory information is presented (e.g. the meaning ofvarious options)

On to your specific questions...

A) The brackets usually denote momentary action: the switch springs back after you push/toggle it (as opposed to staying put until pressed again, or toggled back).

B) Often, these are custom made. The ubiquity of the tiny membrane tactile switch is due to the fact that you can design all kinds of things that press into it, from buttons with really long shafts to harsh environment silicone keypads. You might be able to find a cap, but youmay want to select a different style button instead.

TIP: don't superglue stuff to a (non-sealed) membrane tactile switch. The glue will wick into the innards (even when you suspend it upside down!) and form a nice insulating layer that renders the switch useless! Use (a small amount of) thick glue (or geled Superglue) instead.

Lastly, it can take hours (and sometimes even longer) to spec out and choose components and vendors. You don't want to be stuck with 100,000 switches that aren't going to work (or worse yet, 1,000 switches that do, but 99,000 that you can't obtain!)