[Amps] Massive transformer

[Carl]

I'll assume for the moment that transformer secondary has a center tap which 
would make it a 2500VAC transformer in a FWCT rectifier. At that weight it 
is at least a 500ma CCS rating and likely more. Go to one of the older 
handbooks and look at the PS section. The key to getting the most out of 
that iron is to select only the minimum choke inductance necessary (called 
critical inductance) and followed by a big cap and as high a bleeder 
resistance as the formulas require.

Using a choke with twice the current ratings of the transformer will 
minimize the loss. Properly designed, a choke input filter will deliver over 
90% of the power of a capacitive input filter. HV regulation will be 
excellent.

Tuning the choke with a capacitor is another approach but the tuning can be 
a bit tricky.

Carl
KM1H


----- Original Message ----- 
From: "Gary Patterson" <gpatterson53 at hotmail.com>
To: <amps at contesting.com>
Sent: Monday, January 25, 2010 2:40 PM
Subject: [Amps] Massive transformer


>
>
> I picked up a large maybe 70-80 pound transformer that has only a 115 
> primary.  I measured secondary voltage at about 5200 v.   The secondary 
> resistance is 147 ohms.  Am I correct in assuming I wont get much current 
> out of this??
> GaryW4AF
>
>
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