[sdiy] Power Supply Question

[Magnus Danielson]

From: The Peasant <ecircuit at telus.net>
Subject: Re: [sdiy] Power Supply Question
Date: Sat, 17 Jul 2004 16:28:16 -0600
Message-ID: <1090103296.40f9a800d1a82 at webmail.telus.net>

> 
> Quoting 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.

Cheers,
Magnus