Re: (ET) Buck/boost for E20 charger....

["Bob Murcek" <rmurcek geisinger edu>]

I'd echo that caution.  The way a ferro-resonant transformer works is by
running exactly in sync with the 60Hz line frequency, and the cap is
what tunes it to exactly 60Hz.  When it's in tune, the magnetic field in
the core is a square wave as opposed to sine wave and the core is
saturated at a fairly low voltage.  This provides maximum power output
and makes the output voltage insensitive to line voltage.  

I don't think it's possible to get any more voltage out of it. 
Something a little screwball you could do would be to add a couple of
small transformers to boost the voltage on the way to the diodes.  These
would have to have a current rating similar to the main transformer, but
I suspect that you could find war surplus 5V or 6V "filament"
transformers fairly cheap.

>>> "RJ Kanary" <rjkanary nauticom net> 6/12/2005 11:12:39 PM >>>
      It has been done . Proceed with caution, and meter everything
that's 
going on. Output voltage, current , and line draw . Keep an eye on
diode and 
transformer temperature with an infrared thermometer. Small changes in
the 
capacitor's value can result in dramatic changes elsewhere.

----- Original Message ----- 
From: "Christopher Zach" <czach computer org>
To: "Elec-trak list" <elec-trak cosmos phy tufts edu>
Sent: Sunday, June 12, 2005 11:06 PM
Subject: (ET) Buck/boost for E20 charger....


> Ok, this is going to be interesting.
>
> So I came into possession of approximately 300 SAFT NiCD cells. Each
cell 
> is a BB600 form factor, and puts out 30-40ah at 1.2 volts. Flooded
cells.
>
> That's the cool news. What I want to do is put these puppies into my
E20 
> and get rid of the T105's. I think I can replace a T105 with 15 of
these 
> cells (5 cells wide=6 volts, 3 ranks deep=110ah) and get a tractor
that 
> will run full power in the summer, winter, etc for about 20 years per

> pack.
>
> Problem is charging them. The E20's charger ramps up to 45 volts
IIRC, is 
> it possible to change the cap value and boost the voltage a bit
higher? 
> NiCDs like around 1.6vpc, or 8 volts per 6 volt battery or 48 volts 
> nominal. Add 2 volts to that for the battery control circuit I use
(the TI 
> DQ series) and I would need the Elec-trak transformer to put out a
max of 
> 50 volts.
>
> SO any thoughts on getting that ferro-resonant transformer to have a

> slightly higher secondary without rewinding it?
>
> Chris
>
>
>
> _______________________________________________
> Elec-trak mailing list
> Elec-trak cosmos phy tufts edu 
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak 
> 


_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu 
https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak


IMPORTANT WARNING: The information in this message (and the documents 
attached to it, if any) is confidential and may be legally privileged. It 
is intended solely for the addressee. Access to this message by anyone 
else is unauthorized. If you are not the intended recipient, any 
disclosure, copying, distribution or any action taken, or omitted to be 
taken, in reliance on it is prohibited and may be unlawful. If you have 
received this message in error, please delete all electronic copies of 
this message (and the documents attached to it, if any), destroy any hard 
copies you may have created and notify me immediately by replying to this 
email. Thank you.