On Sun, 2 Jun 2002, Roman Black wrote:

>Peter L. Peres wrote:
>
>> >Thanks Alexandre, that is handy info. The design
>> >will tolerate 100 ohms per contact or so, but i'm
>> >still nervous about contact change in resistance
>> >over time. Would be nice if someone could say
>> >"yes definitely about 100 ohms new, then increasing
>> >to 300 ohms after 10,000 presses etc". :o)
>> >-Roman
>>
>> Okay, here goes: Yes, definitely around 50 ohms new, some 5% increase
>> beyond 500 ohms after 1000 or less presses and/or two months.
>
>
>Thanks Peter, but ouch! That resistance increase is
>not good! What type of keypad, and are the "bad"
>buttons the most used or is this a random effect?

It's an inexpensive rubber keypad purchased in some quantity (comes with a
box + rubber keypad). You supply a PCB with contact patterns to come under
the pads. As with everything else, if you spend enough money and do not
get ripped off by someone then you will buy something better. This was a
surplus that was bought as is.

Peter

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