[Lowfer] power supply info

[Dave Brown]

Sounds like a CVT or constant voltage transformer. And you're correct- they
use a 'tuned circuit' at mains frequency to give rise to the 'constant'
secondary output voltage-hence the use of another winding on the transformer
core with the resonating cap tied across it. The secondary output waveform
is fairly distorted because the core operates in partial saturation all the
time. But this is of no consequence when firing the output straight into a
rectifier-filter and producing DC.
The bad news is that they are designed for a specific output voltage. So
changing the secondary output voltage is not really an option.
While you could get adventurous and try taking off a few secondary turns,
it's certain to change the operating conditions in the core-which has to
operate in partial saturation to get the CVT effect anyway. So a small
change may be achieved without too much effect on the CVT action but a large
change almost certainly will be impossible without rendering the CVT effect
null and void.
73
Dave, ZL3FJ

----- Original Message -----
From: <riese-k3djc@juno.com>
To: <lowfer@mailman.qth.net>
Sent: Wednesday, April 09, 2003 8:21 AM
Subject: [Lowfer] power supply info


> Hi Gang
>
> GTE Linkert built battery chargers that used a special
> transformer that in conjunction with a Cap formed a
> regulated DC output. I have several that have housed mice
>  for several years but today applied AC to one and find
> it works rather well. I believe the transformer was a
> ( ferro resonate ) something or other
>
> anyone have info on this or a basic 'how they operate" ??
> I would like to lower the B+ from 52 volts to 30+-
>
> There heavy so should have plenty of current
> I need to get a good load on one and see what the
> DC looks like, They have some big filter caps in them
>
> Bob  K3DJC
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