[sdiy] flip-flops

[Mountain Man]

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  :)

Elby


patchell wrote:

>     From you description of how you are using the part, everything sounds
> correct (except for the Q output).  First question is, do you have another
> 4027 to try?  Also, the Q output for one flip flop is right next to VDD
> (Q->15, Vdd->16), which you are calling 0 volts.  Is there any posiblility
> that there is a short between pins 15 and 16? (If this is the FF you are
> using).  Since notQ seems to be working, power supply bypassing problems can
> probably be ruled out.
>
>     If you need the CD4027 Data sheet, I can send you one.
>
>     I tried to send you the first page twice now, I am getting some sort of
> error.  If you still need it tomorrow, I will try again. (I hate Windows!)
>
> Mountain Man wrote:
>
> > No, it's not about going to the beach!  It's about trying to get the
> > circuit-du-jour to sit up and beg!  I'm working on a Scott G circuit,
> > that contains 4027 flip-flops.  I haven't been able to get the flip-flop
> > part to work, so I finally ran some stand-alone tests on the 4027.  I
> > have the chip powered using -12V (as ground), and 0V, since that's what
> > the circuit calls for.  I'm feeding the chip clock pulses that alternate
> > between -12V and 0V.  R and S are both connected to -12V, and all unused
> > inputs are as well.  My digital logic book claims that when both J and K
> > are set to 1, the flip-flop should change states on each clock pulse.
> > I've connected J and K to 0V.  I see notQ changing state, between 0 and
> > -12V, on each positive pulse (0V).  Q, however, holds steady at 0V.  Can
> > someone tell me why Q isn't the complement of notQ, as expected?  I've
> > fiddled with this for several hours now, and I have no idea how to
> > proceed.  BTW, I spent quite a while looking for a 4027 datasheet on the
> > web; if anyone has one, I'd appreciate an email  :)
> >
> > Thanks,
> > Elby
>
> --
>  -Jim
> ------------------------------------------------
> * Visit:http://www.silcom.com/~patchell/
> *-----------------------------------------------
> *I'm sure glad Merry Christmas comes just once a year
> * -Yogi Yorgensen
> ------------------------------------------------