[sdiy] faulty switch causing bounce?

[Neil Johnson]

Hi,

Tom Wiltshire wrote:
> My guess: The switch common goes to +5V, one way goes to S and the  
> other to R, which are both tied low with a decent resistor - maybe  
> 10K. If you switch the switch to "S" the flip-flop will get set (S  
> goes high) and bounces will just be further pulses attempting to  
> set the flip-flop. Likewise for Reset - the first contact will  
> reset the flip-flop low, and repeated pulses caused by bounce have  
> no effect.
>
> Am I close?

Exactly right.  Although depending on the exact type of SR you might  
have pull-up resistors and the switch common to ground.

I used this exact trick years ago on a precision ramp waveform  
generator to debounce expensive panel push switches - I didn't want  
any runt pulses around the clock circuits.

Cheers,
Neil
--
http://www.njohnson.co.uk