Don't overlook the AC hi pot testers on ebay that are usually dirt cheap
compared to the DC units. I picked an AC unit up for $15.00 or $20.00. All
you need to do is make a simple voltage doubler, Tripler or quadrupler
depending on how much AC is available from the unit. You don't need much
capacitance for the filters. I used a couple of .002 Mfd @ 6 Kv in a doubler
circuit. A couple of strings of rectifiers and you are in business. If you
also have a couple of 50 or 100 microamp meters you can use one for a
voltmeter and the other as a series current meter. You also need some high
value high voltage resistors for the metering and a series output resistor
to limit the current. I built this on a Plexiglas sheet that stands up and
mounted everything on it including connectors. I just clip the AC hi pot
unit to the Plexiglas unit and I have a nice DC hi pot unit.
The nice part of this is that the AC hi pot unit has built in over current
protection, variable voltage and a voltmeter on it. Very inexpensive for
most of what you need.
73
Gary K4FMX
> -----Original Message-----
> From: amps-bounces@contesting.com [mailto:amps-bounces@contesting.com] On
> Behalf Of Barrie Smith
> Sent: Thursday, January 03, 2008 3:45 PM
> To: Commander John; Steve Katz
> Cc: Amps@contesting.com
> Subject: Re: [Amps] questions about hi pot tester
>
> Commander!
>
> I was in much the same position, in that I had gathered almost all that I
> needed to build a hipot, but the filter caps kept getting away, especially
> price-wise.
>
> I ended up buying a commercial unit on EBay, in the "Industrial
> Electronics"
> section.
>
> Continusously variable voltage from zero to 15 KV, variable load from 2
> microamps on up, two big meters and looks as if it had never been used.
>
> $100.00, shipping included.
>
> 73, Barrie, W7ALW
> ----- Original Message -----
> From: "Commander John" <crazytvjohn@yahoo.com>
> To: "Steve Katz" <stevek@jmr.com>
> Cc: <Amps@contesting.com>
> Sent: Thursday, January 03, 2008 1:18 PM
> Subject: Re: [Amps] questions about hi pot tester
>
>
> > The application is to ham radio related stuff. Not commercial. I do not
> know what I may need to test in the future, so I do not know what to get
> in
> a tester.
> >
> > john w9zy
> >
> > Steve Katz <stevek@jmr.com> wrote:
> > What's the application?
> >
> > A lot of off-the-shelf hipot testers for consumer electronic equipment
> > stop at 6kVdc (because that's the limit of the requirement for
> > compliance testing on a 240V circuit) and that's not nearly high enough
> > voltage to test, say, a high power transmitting tube.
> >
> > Are you looking to do compliance testing, which requires a stipulated
> > ramp time, dwell time and leakage limit? Or just to see where stuff
> > flashes over? How high a voltage?
> >
> > WB2WIK/6
> >
> > _______________________________________________
> > Amps mailing list
> > Amps@contesting.com
> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
>
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