Re: Low THD transformer circuit

On 18 Nov 2006 06:09:30 -0800, Winfield Hill
<Winfield_member@xxxxxxxxxxx> wrote:

John Larkin wrote...
martin griffith wrote:
John Larkin wrote:

Why not load the transformer secondary into a summing point and drive
the primary through a resistor, or from a current source? That would
keep the core at nearly zero flux.

I think that works for input transformers, not output transformers

Well, follow it with a floating-supply amp, just like the input case.
This has 16 floating output channels, each with its own dc/dc
converter. I figure that there are about 86 different supply rails
on this board. http://www.highlandtechnology.com/DSS/V470DS.html
We're using ISDN data transformers as the dc/dc things, about
$1.10 each.

Hmm, +/-15 and +5, etc., for each of the 16 channels, that's 48
supply rails, plus some on the VME side, how do you get 86 rails?

5 rails in each channel. +-18 unreg, +5, +-2.5. The 2.5 rails are for
the chopamps. You can hardly find a chopper amp that tolerates more
than 5 volts r-r any more. So we wind up doing ppm-accuracy stuff with
+-2 volt swings.

John

.

Relevant Pages

  • Re: Low THD transformer circuit
    ... I think that works for input transformers, ... This has 16 floating output channels, each with its own dc/dc ... supply rails, plus some on the VME side, how do you get 86 rails? ...
    (sci.electronics.design)
  • Re: Low THD transformer circuit
    ... Larkin wrote: ... I think that works for input transformers, ... I figure that there are about 86 different supply rails on ...
    (sci.electronics.design)
  • Re: Low THD transformer circuit
    ... I think that works for input transformers, ... This has 16 floating output channels, ... We're using ISDN data transformers as the dc/dc things, ...
    (sci.electronics.design)
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