Re: (ET) Solid state controls

["Christopher Zach" <czach computer org>]

Hm. I've thought about this, and for a tractor, I don't see any advantage 
to
an infinately variable speed control. In fact, I would consider it to be
somewhat of a disadvantage.

When mowing I like to set the speed to a quantum level and forget it. With
an infinite speed control, you never quite know if you're at the best speed
for mowing. Or plowing. Or tilling. With 8 motor speeds plus four gears you
have a range of 32 speeds between 0 and 9 mph. The greatest thing on the 
E20
IMHO is the cruise control lock-in.

Then there's the efficiency. Running full field/full armature is the most
efficient way to go with the elec-trak motors. Use the gears to modulate 
the
speed; don't lose 5%-10% of the power thru a controller (the relays and
solenoids are probably >99% efficient).

Also would need to make sure that any controller could *fully* support
regen. The elec-trak does have significant regen, and dumpstering it is
going to decrease your range and put a significant load on your brakes. 
I've
dropped regen on hills; the brakes have to work very very hard.

Chris