[time-nuts] HP5370A A22 arming assembly circuit diagram error

[John Miles]

In the 5370B manual (2940A prefix), it looks like they are running U7 from
+5 on pin 3 and -5.2 on pin 12.  Probably a drafting error in the -A manual.

-- john, KE5FX


> Dr Bruce Griffiths wrote:
> > Correction to previous post. (typed U7 instead of U6 VVC connected too
> > ground OK for U7 as inputs are ECL levels. )
> >
> > The positive supply connection to A22:U7 (LM339 quad comparator) is
> > shown as ground in the circuit diagram.
> > This is surely incorrect as the inputs of U6B and U6C are connected to
> > TTL(+5V VCC) signals.
> >
> > Surely this is not the designers intention
> > The positive supply of A22:U6 should be +5V.
> >
> > Is there a manual change correcting this schematic error that I have
> > missed?
> >
> > If A22:U6 positive supply is indeed ground, the circuit may still work
> > but its reliability will be compromised by the relatively large
> currents
> > flowing into A22:U6C&D input substrate diodes.
> >
> > Bruce
>