[sdiy] flip-flops

[Magnus Danielson]

From: Mountain Man <mtman at cloud9.net>
Subject: Re: [sdiy] flip-flops
Date: Fri, 18 May 2001 23:34:46 -0400

> I've tried a couple of chips with the same results.  The Q output
> I'm checking is on pin 1, so the short you suggest isn't the
> problem.   I'll take you up on the offer of the datasheet, if you
> can get Windows to behave!   And thanks  :)

I dug out my RCA CMOS databook from 1982 - a classic - and reading
your email through I found nothing wrong on how you connect things.
If the Q output does not change properly while the ~Q does change
correctly, then I would suspect that the logical function is correct
but that either the output is toast or shorted into its state. If you
look carefull at the actual curcuit structure you will see that the
internal signal versions of Q and ~Q is separated by 1 or 2
inverters. So, it may function correctly even if one of the outputs
may be fooged up.

So, check if the output goes clear of shorts and if there is something
hooked to it that could pull it to the wrong state.

PS. I could dig up the 4027 datasheet and pass it over, since I am
free from the burdens of MS Windows!

Cheers,
Magnus - who flip-flopps all over the office in my antistatic slippers