Bill Dube wrote:
AC, not DC powered. Transformer changes ~13 kv distribution voltage down
to 480 vac.
Cord reels ("coils") consist of three conductor wire with current
flowing equally in both directions, so there is no inductance associated
with the "coil". Thus no inductive heating from the AC.
Bill has it right. When you have equal and opposite currents flowing in
the wires, their magnetic fields (largely) cancel. Thus, the inductance
(largely) cancels out.
There wouldn't be an inductive problem with DC in the cable, either. But
arcing would be in case of trouble, and changing the voltage gets a lot
harder. You want as high a voltage as possible in the cable, to minimize
the size of the wire and its resistive losses. But motors and motor
controllers are easier to build for lower voltages (and higher
currents). Transformers are the easiest way to deal with this.
--
Don't worry about people stealing your ideas. If your ideas are any
good, you'll have to ram them down people's throats. -- Howard Aiken
--
Lee Hart -- see my EV projects and Balancer at
www.sunrise-ev.com/Balancer.htm
_______________________________________________
UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
http://lists.evdl.org/listinfo.cgi/ev-evdl.org
For EV drag racing discussion, please use NEDRA
(http://groups.yahoo.com/group/NEDRA)
