[sdiy] faulty switch causing bounce?

[Scott Gravenhorst]

Tom Wiltshire <tom at electricdruid.net> wrote:
>
>On 27 Aug 2010, at 16:35, cheater cheater wrote:
>
>>> The best debouncer I've ever used is a SPDT switch and an SR 
>latch (flip-flop?). That's what I would use for important 
>heavy-use switches like a sequencer manual step switch. > > Very 
>interesting - how does that work? > > Cheers, > D. 
>
>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?
>
>T.

Yep.  I've seen this in some books.  It works very well, even with very
bouncy switches.


-- ScottG
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