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Re: [N8VEM: 14588] Switch debouncing and related stuff (like CPU reset circuits)

On 9/09/2012 4:50 PM, Sergey wrote:

Hi,

Electrical engineers among us, please correct me if I wrong :-)

I was designing an ATX power-on circuit for my next 8088/XT board, and
one of the issues was debouncing of the power switch (which is a
momentary switch).

It must be some kind of conspiracy about switch debouncing, it looks
like 90% of the related pages on the Internet are referring to this
"research": http://www.ganssle.com/debouncing-pt2.htm . More exactly
to the circuit on Figure 3 (the circuit on Figure 1, which also
frequently referred everywhere, is mostly unusable, since nobody will
use a double throw switch just to overcome the contact bounce)


Snip

There are three pin econo reset chips around such as the Dallas DS1813.
They are normally open collector, sometimes with an internal pullup resistor
and start a timer when the switch shorts to ground and holds the output low
until some period after the switch is released.

I'm not sure if that is what you are looking for.
I have a data sheet for the DS1813 if you are interested.
There are a number of similar chips and I think Motorola make some too.

John