I agree this article is pretty good. It's the first scientific treatment
of switches I've read. (I'm new to electronics and just learning.) I'm
also pleased to surmise that Mr. Ganssle lives in the Baltimore area --
he knows Baynesville Electronics, and I've been buying heavily from them
lately. They are pretty good and do have a treasure trove of switches.

Makes me wonder how much a standard American 110/120v house wall switch
bounces. Would it even switch at 5v?

Thanks

Bob Cochran


James Newton, Host wrote:
> source= http://www.piclist.com/piclist/2004/03/26/033108a.txt?
>
> Matt Pobursky  says:
>
>>Here's an article by Jack Ganssle exploring mechanical
>>switches and contact bounce:
>>
>>
>>http://www.embedded.com/showArticle.jhtml?articleID=18400810
>>
>
>
> Actually, that was one of the better articles I've ever read on the subject.
>
>
>>From what I could gather, an RC filter would actually make the bouncing
> worse, and hysterisys (sp?), a comparator, and/or schmidt trigger should
> make it better because a lot of it comes from time spent crossing over the
> "illegal" range between a 0 and a 1.
>
> Has anyone tried that sort of hardware debouncing?
>
> Also, he says those "cheap" membrane, carbon button type switches are almost
> bounce free except for the time spent in "no mans land."
>
> ---
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--
Bob Cochran
Greenbelt, Maryland, USA
http://greenbeltcomputer.biz/

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