Is This Right? ( 555 and 4024)

[gtr_stitch]

Hey all,

Just curious...is this circuit right?

Just kinda double checking... major n00b here lol

Thanks!

 

[audioguru]

You have pin 1 of the CD4024 shorted to ground.
The resistor from pin 3 of the 555 and pin 1 of the CD4024 is useless and can be replaced by a piece of wire.
A supply bypass capacitor is missing.

 

[gtr_stitch]

I knew the bypass cap was gonna come up

Hmm...okay, that's what I thought. That being so, then there are some false circuits floating around out there...deceiving poor minds like my own! Check it out...

Anyways, cool. That explains the erradic behavior. Thanks!

 

[MikeMl]

That circuit is crap! About 75% of circuits posted on the web are put up by noobs who are much better at screwing with html than they are electrical engineers.

First, Since the 4024 is a binary counter, and multiple outputs can be on at the same time, the LEDs connected to the outputs cannot share one common resistor.

Second, the push-button used to generate the clock input needs to be "de-bounced" because if connected as shown, the switch generates "glitches" (multiple spurious rapid closings/openings) which will advance the counter unpredictably.

Third, it needs a bypass capacitor across the power pins on the counter.

btw- I went and looked at about five circuits posted on that site. I found similar deficiencies with almost every one I looked at.

 

[Boncuk]

Hi,

hopefully this circuit will perform as required.

Boncuk