Rubber button enclosure inserts?

[Things]

I'm working on a project at the moment that requires a single momentary button, however the whole thing will be inside a small enclosure, which I'd like to try get as "water resistant" as possible. I would like to be able to mount the button on the PCB, and my idea was to simply have a small rubber piece that squeezes through a hole in the enclosure, and presses the button (PCB would only be sitting a few mm away from the side of the enclosure).



Sounds simple enough .. but where do you get little rubber inserts like this? Are they usually custom made or is there something generic out there anyone is aware of?

Something like this, but in rubber:



Cheers

[Psi]

Yep, the rubber button inserts are custom made for the device

If your project has a mcu have a look to see if you can do capacitive touchbuttons. They will work through the plastic enclosure

[Things]

I would like to be able to use capacitive buttons, but the button also has to act as a power button The device will be powered by a small LiPo so quiescent draw is an issue.

[Psi]

What about a magnetic button, have a reed switch inside the enclosure and something on the outside that moves a magnet closer to the enclosure when pressed.
Or maybe a slider which slides a magnet between two positions

[PeterFW]

I'm working on a project at the moment that requires a single momentary button, however the whole thing will be inside a small enclosure, which I'd like to try get as "water resistant" as possible.

I have worked with rugged explosives equipment that used reed switches and external mounted magnets and/or "magnet pens" to achive a complete seal.

[Things]

Reed switch also came to mind, though I'm not really sure how to use that in a momentary pushbutton style setup. I'm also kind of wondering whether you can buy those rubber buttons with the metallized rubber contact underneath, like on calculators, but separately. Might be able to get a reasonable seal if it's sandwiched between the PCB and enclosure?

[PeterFW]

Reed switch also came to mind, though I'm not really sure how to use that in a momentary pushbutton style setup.

Pretty easy but a bit of engineering needet, something sliding, rotating, swinging with detents or magnet latches.

I'm also kind of wondering whether you can buy those rubber buttons with the metallized rubber contact underneath, like on calculators, but separately. Might be able to get a reasonable seal if it's sandwiched between the PCB and enclosure?

Yes you can, but they are pretty big, at least the ones i was able to find.
You could get a complete rubber keypads and just cut it apart...

What you can get pretty easily are single membrane switches:
http://www.conrad.com/medias/global/ce/7000_7999/7000/7090/7098/709883_BB_00_FB.EPS_1000.jpg
http://image.ec21.com/image/beautiful1988/oimg_GC05984249_CA06069801/One_Button_Membrane_Switch.jpg

[Things]

Actually, on a similar note I looked over on my bench and saw the little silicone tailcap on my torch and it gave me an idea. Turns out these are available down to about 10mm in diameter, which is still a little large, but definitely useable. I can use a regular SMD momentary pushbutton with a small actuator, + one of these tailcap boots shoved (and maybe glued) to the inside of the enclosure!

[lgbeno]

I would like to be able to use capacitive buttons, but the button also has to act as a power button The device will be powered by a small LiPo so quiescent draw is an issue.

Some cap sense libraries are very low power.  For example EFM32.


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