[Test-Equipment] Need to shift pulse up 5V

[Barry]

Scratch that.  I found the full manual with all schematics.  Truthfully, I hadn't looked for them before as I wasn't sure I would need them but this should help tremendously.

Thanks,
Barry - N4BUQ

----- Original Message -----
> From: "Barry" <n4buq at knology.net>
> To: "Discussion of Electronic Test Equipment" <test-equipment at mailman.qth.net>
> Sent: Friday, May 1, 2015 1:45:48 PM
> Subject: Re: [Test-Equipment] Need to shift pulse up 5V
> 
> I think that's what the latches in the new circuitry will want but I need to
> do more reading on those as well as more analysis of the strobe and data
> signals.
> 
> Unfortunately, I do not have a full schematic and am working with what I can
> surmise from what I do have of it (which isn't very much...).  I do plan to
> go with significantly higher resistors at first as a safety factor and work
> my way down if necessary.
> 
> Thanks again,
> Barry - N4BUQ
> 
> ----- Original Message -----
> > From: "Mike Manes" <mrmanes at gmail.com>
> > To: "Discussion of Electronic Test Equipment"
> > <test-equipment at mailman.qth.net>
> > Sent: Friday, May 1, 2015 1:33:10 PM
> > Subject: Re: [Test-Equipment] Need to shift pulse up 5V
> > 
> > Hi Barry,
> > 
> > The base is at ground, and when the NPN is saturated, the collector
> > voltage can actually go >below< the base voltage in a common emitter
> > configuration.  I 'd expect that in the grounded base setup, Vcb will
> > come pretty close to zero. I picked the 4.7K values to set Ic & Ie to
> > about 1 mA; not sure if your load sources or sinks current nor how
> > much.
> > 
> > OK on the latching function - so the NPN will keep the strobe polarity,
> > but it's not clear that's what your +5V circuitry wants.
> > 
> > 73 es GL de Mike W5VSI
> > 
> > On 5/1/15 12:05, Barry wrote:
> > > I see it now. I was thinking of it incorrectly. When the NPN is
> > conducting, the two equal-value resistors form a voltage divider between
> > +5V and -5V and when it is not conducting, that point is seeing +5V so -
> > non-inverting.
> > >
> > > One small point: doesn't the transistor's two diode-drops come into
> > the equation effectively shifting that zero point when it is conducting?
> > >
> > > I have a handful of 2N3904s so I will be trying this soon and, I
> > > agree
> > - definitely a more elegant solution than a comparator.
> > >
> > > BTW, these are strobe signals that set latches so not sure if an
> > inverted clock would be okay but it might. With a non-inverted pulse,
> > though, I won't worry about it.
> > 
> > > Thanks again,
> > > Barry - N4BUQ
> > ______________________________________________________________
> > Test-Equipment mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/test-equipment
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:Test-Equipment at mailman.qth.net
> > 
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> > 
> ______________________________________________________________
> Test-Equipment mailing list
> Home: http://mailman.qth.net/mailman/listinfo/test-equipment
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Test-Equipment at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>