Correction. The output should be close to 5 volts. With the process of
elimination, try hooking the 100k to the cap and 5 volts. Measure the cap to see
if it charges up to 5 volts. Don't forget, the load of the voltmeter will
discharge the cap. Add the diode and see how much of a charge you get. Then add
the logic out from the gate.

I think this is a moot point anyway. All you are detecting is the threshold to
the next gate. If it does not trigger, then it sounds like you have a leakage
problem in the cap.
Rick

"Rick C." wrote:

> The data sheet says 4.5 volts logic high.
> Download the pdf at my site at:
> http://www.pic101.com/74HC14.PDF
> Rick
>
> Chris Emerson wrote:
>
> > On Sat, Dec 06, 2003 at 06:04:03PM -0500, Rick C. wrote:
> > > The output of U1B will never go to 5 volts. Probably over a volt or more
> > > from 5 volts.
> >
> > It does according to my multimeter (at least when unloaded) - note it's
> > a 74HC14 not the 7414 I've confusingly got in the diagram.  Or is there
> > some other reason?
> >
> > Thanks,
> >
> > Chris
> >
> > --

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