glenn
if you have reasonable equalising resistors across the capacitor string
that will give sufficient load to stop the no load volts soaring and you can
fire the thing up slowly from zero volts to primary with a variac [best] or
start with a low watts bulb in series with the line, and run for a bit, then
substitute next bulb up etc. this way the electros have a chance to form and
any tendency to catastrophic breakdown is detected early.
In operation ht volts can be expected to sag maybe 5% with standing load of
the tube, another 5-10% drop at full load.
73
end
Barry Kirkwood PhD ZL1DD
Signal Hill Homestay
66 Cory Road
Palm Beach
Waiheke Island 1240
NEW ZEALAND
www.waiheke.co.nz/signal.htm
----- Original Message -----
From: Glenn McNeil <vk4tzl@bigpond.com>
To: <amps@contesting.com>
Sent: Thursday, 17 May, 2001 2:45 PM
Subject: [AMPS] Voltage Doublers...thanks for the info.
>
> To Rich, Dick, Steve and Ian...and any others I may have missed...
>
> Thanks for all your input. Certainly there is more to FWD than I thought
about.
>
> Further delving into the transformers background at this end has come up
with the following :
>
> Primary Resistance is 1.4 ohms
> Secondary Resistance is 12 ohms
> I intend to use 5 x 190uf 400v caps in each leg with 1N5408 diodes.
> I'm only trying to run a single 4CX250R
> After sifting through lots of paper, I have discovered that the no load
secondary voltage is 830 vac, up from my
> approximate guess of 750 vac.
> The transformer will only be supplying EHT...no other voltages.
>
> I think Steve suggested a lash up first....my metalwork at this stage will
allow this.
>
> I have a copy of a Yaesu power supply in one of their linears...not sure
which one, as I only have the relevant bit
> after the transformer, which is very similar to what I have...850v with
100uf 500v caps....albeit I dont know what the
> transformer specs are.
>
> Anyway, now how to figure out how to load the lash up to see what I
achieve.
>
> 73
>
> Glenn
> VK4TZL
>
>
>
>
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>
>
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