Hi Dudley,
The DTR-2000 used a voltage tripler? I don't recall that...do you have a
schematic? It's certainly an unusual application for a 1A supply.
Of course I am aware that many amps use doublers; this is normally as high a
multiplication factor as is found in such applications.
Would love to see the DTR-2000 schematic, look up the capacitor values and
calculate regulation & ripple. Ripple at 1Adc using a tripler is
predictably not good...but, then, as I recall I think the DTR-2000 applied
close to 6V on the 8877 heater under normal line conditions, leading to lots
of premature tube failures.
WB2WIK/6
"If everything seems under control, you're just not going fast enough." -
Mario Andretti
> -----Original Message-----
> From: Dudley Hurry [SMTP:jhurry@austin.rr.com]
> Sent: Tuesday, October 15, 2002 12:33 PM
> To: Steve Katz; amps@contesting.com
> Subject: Re: [Amps] voltage multiplier shown
>
> 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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