Driving modern 120 VAC accessories (was: RE: (ET) Battery maintainers)

["Chris Tromley" <chris_t microtrac com>]

Chris Zach wrote:

> I think honestly the best way to do things on an Elec-Trak is 
> to get a 36-120 volt AC inverter and just run AC tools. Think 
> 3600 watts of power and you're in business. Then you can hook 
> up the best electric tool you can find, and if you find one 
> with an auto-power on and off it's flawless.

Hi Chris,

You have touched on a major problem for me.  I'm closing in on my first 
year
in a new house with a nice big yard, which is why the concept of an ET
quickly went from an interest to a necessity.  Mowing is now a pleasure,
snow plowing is yet to be experienced (I'm ready and eager to try it), but
dealing with leaves and downed branches is still a major headache.

I got a Patriot electric chipper/shredder
http://www.patriot-products-inc.com/products.htm#eleccsv that I'm happy
with.  But the raking and shredding still takes a *huge* amount of time.
Since the shredder also acts as a vacuum, the most time-efficient solution
is to mount it on a tow cart and lift/shred the leaves in one pass.  But
that means powering the shredder from the ET.

It's rated at 120 VAC and 13 amps, but I'm not sure of the actual load 
under
varying conditions.  A 3600 watt inverter is maybe overkill.  But the only
thing I've found that runs from 36 VDC is a Tripp-Lite APS 3636(?)
inverter/charger.  Comfortable power "headroom", plus a nice charger, but
the low low eBay price is $820.  Way more than I paid for my ET.  Or the
shredder.  Finding an inverter that runs from 36 VDC is Very Difficult.
Hmmm, maybe get a bunch of us together for a volume purchase?

Does anyone think I might have any luck finding a more common 800-1000 watt
inverter that runs off 12 VDC that could be paralleled?  I'd run three to
keep the pack balanced.  I'm an electrical dummy, but I know there would
have to be a provision to synch the outputs.  Anyone heard of such a 
feature
on this type of inverter?

I've also considered using two of the GE rotary inverters in parallel,
coupled or belted together in a way that keeps the outputs in phase.  Is
this workable?  Or maybe make my own rotary inverter from a surplus motor
and alternator?  Being an electrical dummy, this seems a high-risk option
for me.  I would need specific guidance.  How efficient could something 
like
this be?

I could also replace the motor on the shredder with a 36 VDC unit, but what
kind?  I think series-wound is out, since overspeeding is an issue.  There
would probably be lots of machining involved as well.  Not to mention that
the shredder would then become an ET-only tool, which is inconvenient, and
it does nothing to solve the problem of the 120 VAC, 12 amp electric chain
saw I just got....

I'm betting I'm not the only one with these problems.  If anyone can offer
suggestions that are reasonably easy to put into low-volume production, I'm
happy to develop a solution and make it available to the community.  (Well,
that is if there isn't too much electricity involved. :-)  Maybe a high
output rotary inverter, or plans for a vac/shredder/dump cart?

I hope to solve this problem before next fall.  Any help will be greatly
appreciated.

Chris Tromley
near Philadelphia  PA  USA

100% Gas-Free Yard Equipment:
* Avco New Idea EGT 150 electric tractor
  with mid-mount mower deck and snow blade
* B&D corded electric mower and string trimmer
* Patriot 1.5 hp electric chipper/shredder/vac
* Remington Garden Wizard corded electric tiller
* Craftsman corded electric snow thrower