Debouncing circuit help!

[seekee]

Hi. I'm currently working on a project and it requires debouncing circuit. I have a 74ls192 up down counter. The clock for the up and down pins will be push buttons. I need to have debouncing circuit for it.

 

[Sebi]

Choose one...

 

[bonxer]

**broken link removed**

Lots of reading and detail. At least there's pictures. Check out Figure 2: An RC debouncer. I personally never use R2, and I have never had bounce problems. Then again I'm not working on the shuttle either. 8)

 

[Sebi]

R2 reduce the discharge current, and prevent the switch erosion. When You have a 10A microswitch no problem if omitted.

 

[bonxer]

Of course then again, I'm the kind of guy that likes to charge capacitors up to around 35 volts or so and then strike the leads against a piece of metal to short, make it spark, and give a nice popping sound. The temorary welding effect is a bonus feature. :twisted:

 

[ljcox]

In order to ensure reliable operation, switch contacts need at least 5 Volt across them when open and at least 1 mA of current through them when closed.

This prevents the build up of an insulating film on the contact surfaces and therefore eventual failure.

Len

 

[Juglenaut]

Hex inverted with schmitt trigger. 7414 LS or better.

I also found that an AND gate works good, just tie one high and use the other input for the switch signal. HC series works best here.

 

[Random]

Bumping a dead topic, sorry, but if one could make the circuit work with an inverted switch, would the NOT gate still be needed?

 

[ljcox]

Bumping a dead topic, sorry, but if one could make the circuit work with an inverted switch, would the NOT gate still be needed?

I don't understand your question.

But this subject has been covered before, see for eaxmple https://www.electro-tech-online.com/threads/pic-c-complier-free-version.6386/

Len