Re: (ET) 48v ET

[Christopher Zach <czach computer org>]

I think the tractor's main motor would handle it without too much 
trouble. However: I think the mower deck motors might have a serious 
problem being PM motors. On the main motor, the shunt voltage goes up 
with armature voltage, increashing the field strength. On a PM motor, 
the magnets mean the field is fixed.

The other thing to think about is that the contactors and all are rated 
for 36 volts. Running them at 48 volts means that you have just exceeded 
their threshold. They may arc, or burn out more quickly, or (in a really 
bad case) fail to stop the tractor by welding on.

*HOWEVER* If you want to run a 48 volt inverter I don't see why you 
couldn't put an extra 12 volt battery in series with the 36 volts, then 
attach the inverter to that. Just make sure to charge the top 12 volt 
battery with it's own charger and let the Elec-trak charge the other 
batteries (which will be flat together)

Chris



robert winfield wrote:
> Is a 48v ET doable? It would make things much simpler.
> I could yank out that dratted charger and squeeze 4
> batteries in that area. E12
> Obviously it wouldn't void the warrenty but would it
> fry the components with 33% more voltage. (visions of
> Tim "tooltime" breaking stuff)
> I am setting up Photovoltaics to do my charging
> (shortage of big wattage PV in the US, Germany, soon
> Italy and Spain are greening their countries with
> federal subsidies so our prices are up)
> 24 and 48 volts seem a lot easier to get components
> for
>
> --- Anton Berteaux <krustyacres earthlink net> wrote:
>
> > also very much less efficient, and most of the
> > better quality (read 
> > expensive ) electronic inverters are very close to
> > sine wave with less 
> > distortion than a generator.
> > I would up the system voltage to 48, which allows
> > use of many off the 
> > shelf inverters, and makes you go faster, too.
> > anton
> >
> > On May 27, 2004, at 10:46 AM, Dan Conine wrote:
> >
> >
> > > A rotary inverter (in this case) is a 36VDC motor
> >
> > which is run by the 
> >
> > > tractor. The motor is directly coupled to a 110VAC
> >
> > generator.
> >
> > > You get perfect sinusoidal power, vs. the
> >
> > psuedo-simulated(modified 
> >
> > > sine wave) power from a solid-state inverter. 
> >
> > Simple, relatively easy 
> >
> > > to repair if you are living with a soldering iron
> >
> > and a roll of magnet 
> >
> > > wire, and  civilization is gone.
> > > Disadvantage: brushes, bearings, armatures wear
> >
> > out.
> >
> > > Dan Conine
> > > 42
> > > E15, E10
> > > Belgium,WI
> > >
> > >
> > > _______________________________________________
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> > > Elec-trak cosmos phy tufts edu
> https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak
>
> > >
> > Warm globally,
> > Drive locally
> >
> >
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>
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