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[Amps] voltage multiplier shown

To: <amps@contesting.com>
Subject: [Amps] voltage multiplier shown
From: jhurry@austin.rr.com (Dudley Hurry)
Date: Tue, 15 Oct 2002 14:32:37 -0500
Steve,

You know that voltage doublers are used in alot of amps today..    Even some
have triplers, as in the Dentron DTR2000 which could produce one amp at 2500
volts for a 8877 tube.

Thanks and 73's,
Dudley
WA5QPZ
jhurry@austin.rr.com




> John, and especially Rich (AG6K), I did look up the formula for voltage
> multiplier regulation and ripple and a 6x multiplier used to provide 500mA
> when driven by a 60 Hz source is an impossibility.  Voltage drop per the
> formula, assuming 560 uF capacitors are used in a 6-stage multiplier,
> exceeds the output voltage target (1500V), meaning that under 1/2A load, a
> 60 Hz 6x multiplier using 560 uF capacitors would have an output voltage
of
> zero.
>
> The formula is found here:
>
> http://home.earthlink.net/~jimlux/hv/cw1.htm
>
> I do seem to recall from my old voltage multiplier design days that the
only
> serious application for multipliers in the 6x range would be at low load
> currents, or  high operating frequencies, or preferably both.  Most
> multistage (> 2x) voltage multipliers do operate at >15 kHz, and are used
in
> applications where regulation and ripple are not particularly important.
>
> There seems to be some reasoning behind the fact that even amateur
equipment
> containing HV supplies never seems to use > 2x multipliers (doublers); I
> would imagine if 3x or greater multiplication resulted in a weight or cost
> savings, or allowed reasonable performance at equivalent weight and cost
> compared with HV transformers, they would be in popular use.
>
> WB2WIK/6
>
> "If everything seems under control, you're just not going fast enough." -
> Mario Andretti
>
> > -----Original Message-----
> > From: John T. M. Lyles [SMTP:jtml@lanl.gov]
> > Sent: Tuesday, October 15, 2002 9:51 AM
> > To: amps@contesting.com
> > Subject: [Amps] voltage multiplier shown
> >
> > We use a voltage multiplier to get about 700 kV DC at work. Its
> > large, about the size of a small cottage. To get around using 60 Hz
> > iron, we drive it with audio around 5 - 10 KHz, and do the conversion
> > at that frequency. Pair of 3CW20,000s used in the audio driver, which
> > then drives a step up output transformer, in oil. From this it goes
> > upstairs into the voltage multiplier rectifier/capacitor stacks.  The
> > filter/storage caps are much smaller then, about the size of a humans
> > leg (each one). There is a dc feedback loop around the entire supply,
> > to regulate it.
> >
> > One can take a tour at:
> > http://lansce.lanl.gov/overview/tour/index_tour.htm
> > Place your cursor over the injector area, you see a photo showing the
> > size of the voltage multipler, with the man standing beside it with a
> > shorting stick.
> >
> > This is used to charge ions and accelerate them from resting state,
> > in a device known as a Cockroft-Walton accelerator. Such was
> > developed by Lord Cockroft in UK, in the early 1930s i believe. This
> > was the beginnings of ion accelerators in early 'big' science. Most
> > particle laboratories have dumped their CW's and gone to a small RF
> > quadrapole accelerator at the front end. We still run ours; it was
> > shown on an episode of Bill Nye the science guy (kids show) and also
> > on the Horizon channel in years back.
> >
> > 73
> > John
> > K5PRO
> > --
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