On 3 Aug 2000, at 19:43, Chris Eddy wrote:

> Colleagues:
>
> I have a circuit with a 74LS73 wired as a toggle flip flop, or div by
> 2.  In order to do that, you tie the J and K to +5V.  It works for the
> most part, until I drop the frequency below 30 hertz.  The darned thing
> just packs up and stops toggling the output.  Raise the frequency a tad,
> and it start up again.  I have decoupling on the part.  I have fast
> (reasonably) rise times.  The problem happens in circuit and out of
> circuit.
>
> I am using the LS family because I can (presumably) still get 54LS
> family parts.  The customer wants to have mil parts in his product.
>
> I may try HC logic next, jsut to see if it is the LS family.
>
> Any grand ideas?
> Thanks
> Chris Eddy

Its probably not the problem here but I went quietly mad trying to
figure out why I couldnt get a monostable I.C. to work once.
I eventually figured out the data book had the wrong pin outs!!!!!!
Good old Nat Semi.

Have you tied set and clear to the appropriate rails and not just left
them 'flapping in the wind'?


_____________________________

Lance Allen
Technical Officer
Uni of Auckland
Psych Dept
New Zealand

www.psych.auckland.ac.nz

_____________________________

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics