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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