Can tact switches be under permanent pressure?

I would roll a magnetic solution because that is the one with the least sensitivity to dust and stuff. However, I still have too many electronics projects on the various burners and really don't want another one. Plus I'd have to open both Genie drives to sketch up the sense electronics inside to make the interface properly.

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Regards, Joerg 

http://www.analogconsultants.com/
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Joerg
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The old fashonied limit switch would seem effective. Thats most typically the "Microswitch" of the last century. They are available in sizes down to roughly 3/16 by 3/8 by 3/4 along with all sorts actuating levers. The hole can usually be pointed down to reduce the bother of dust & garbage & the neighbor's cat.

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has/had attractive prices. Mouser & Digi-key also have them if memory serves. These will give you something to do before Saturday's mid morning coffee.

Hul

Joerg wrote:

Reply to
Hul Tytus

I have some but they are too large. It would require mechanical mods to get that in there. Times four because there are two on each garage door opener. I think I am going to do a McGyver, shaping the contact tongue into a needle that buries itself into the receptor metal every time it closes. In my teenage days I made limit switches out of thumb tacks and, unlike the commercial ones from Genie, those never failed.

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has/had attractive prices. Mouser &

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89 cents. Highway robbery! :-)

No coffee, I am going to brew a Honey Stout and a Koelsch.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

I have had to replace tact switches because of some sort of film that forms on the contacts. I think maybe the contacts were silver and went black from sulfides. Anyway, a lot of tact switches that I salvaged in my youth from dead VCRs etc. were not really useable because the contact resistance was too high. I suspect that outdoor air might accelerate this process.

Reply to
Chris Jones

Ouch. That could be the case with modern ones as well.

How about the larger ones that sound there is a machanical click mechanism in them? Like these but without LEDs:

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Some have smaller height and would save me a lot of mechanical work because they can go under the old springs.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

No idea. They say they have gold plating, and if that is thick enough, and *if* no dust can get in, then maybe it is ok.

I would try to go for a reed switch and magnet, if that will fit. They are also not entirely reliable but at least the outdoor air should have no influence.

I wonder whether there would be some way to convey the movement to a sealed microswitch fitted near where the switch is at present. I know you said that it would not fit where the existing switch goes, but without a photo, I don't understand the limitations any more than that.

I guess it might be possible to use the original switches but with a higher voltage being switched, and then a sealed relay to convey the status to whatever electronics requires the signal. With a much higher voltage, the dirt on the contacts may not be a problem, but the switch might not be safe if it wasn't designed for that.

Reply to
Chris Jones

Reed switches on doors suffer from vibration & alignment issues. They also can't carry much current reliably, which might or might not be relevant here. And really they're not one of the more long term reliable types anyway.

A set of switches in // or 4 in series // could improve things some. You might even be able to add indicators.

NT

Reply to
tabbypurr

It is possible to fit, just a lot of work. I just may have to do it.

Yes, someone might get on a ladder, reach over ... BZZZZT :-)

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

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