Large Knight Rider project

[gamerscloset]

I'm interested in doubling the amount of led's used by the knight rider project, but I'm not sure how to go about it. Basically, I'm not sure how I can switch from Counter #1 to Counter #2, and when I do so, stop the previous counter. And, ofcourse, vise versa.

Thanks for any help,
GamersCloset

 

[vainajala]

Hi gamerscloset!

I found this application from Philips' HEF4017 datasheet, and modified it a bit for dual counters... I think this would work nicely for you

View attachment 35484

 

[vainajala]

Sorry, but I forgot to add one wire (from second counter's last output pin to first counter's reset pin)
It might still contain errors, but I think this is the way to go...

View attachment 35485

 

[gamerscloset]

Thanks vainajala, I just have a couple questions.

On a 4017 pin 13 is the Clock Inhibit. It looks like from your diagram that once pin 11 goes high, pin 13 will always be high? Maybe I'm not understanding the Clock Inhibit correctly, but I thought that with 13 being high, the counter stops until 13 goes low?

I'm unable to find out what component 7408N is. Is it an And gate?

Thanks,
GamersCloset

 

[xwarp]

7408(N,J) is a Quadruple 2-input positive and gates.

74ls08, 74s08, 54ls08, 54s08, 5408 are the same chip.

 

[vainajala]

This is what the original version looks like...

View attachment 35488