[sdiy] Power Supply Question

[allenre at umich.edu]

> > > I have an HP 6205B dual power supply.
> > >
> > > Both sides are havnig the same problem:  When I measure voltage from +/-
> > > inputs
> > > I only get the positive voltage, i.e. if the meter reads 15V my meter
> reads
> > > only +15V.  If I measure voltage from +VDC or -VDC to GND I don't get any
> > > reading (0V).
> >
> > From what you have written, I'd say the power supply is working correctly.
> Each
> > side only puts out one voltage, between the + and - terminals. The ground
> > terminal is only for referencing the output to ac ground, which is why you
> > won't normally get a reading between it and the other terminals. Most older
> HP
> > supplies work this way.
>
> Actually, even newer HP supplies can have this quirk. The supplies can be
> made
> floating and then you set it for a particular voltage with a positive (+)
> pole
> and a negative (-) pole. You can then bang a few supplies in series if you
> like...
>
> It's confusing but the designed behaviour. From what it sounded to me you are
> alright, you only need to understand what it really does.

That it is working sounds great to me, I just can't get it to work with my
circuit.

I built a VCO3, and I have spent a couple weeks going over the board, looking
for flaws but I'm convinced it is built correctly.  I've even pulled and tested
components, so all I'm left with is the power.

I've begun testing section by section, and I know the integrator isn't working. 
Not only that, I've duplicated it separately on a breadboard and it still won't
work.  This is what has led me to the power supply question.

If I apply a constant current I should get either a rising or falling voltage
out of the integrator, right?

Ryan