Re: [N8VEM: 14598] Switch debouncing and related stuff (like CPU reset circuits)

[John Coffman <john...@gmail.com>]

The SPDT switch must be of the "break-before-make" variety, and the circuit works AS IS.

The solution is unorthodox, but so extremely simple.


On 09/09/2012 09:17 AM, Al Kossow wrote:

On 9/9/12 8:42 AM, John Coffman wrote:

This circuit shorts the output of a gate to ground for no more than 10ns

The NC side (SW output) is shorted unless you push the button.
Use an open collector inverter if you're going to try this.

NO!!!  Use a 74LS04.

I'm
not even sure if this really does what you think it does. During
a switch bounce, neither side of the switch will be low.

SPDT switches don't bounce from one state to another; the bounce is on the contact being made:  either NO or NC.  The inverters switch so fast, that no mechanical bounce is ever seen.

Believe me, I've used this circuit a lot of places with 100.0000000% reliability.

--John