(ET) Upgrades

[russell239 juno com]

I have like most of us on list have a couple of Electracs.  It is so nice
to leave them as is and original condition but getting parts can be a
night mare.    I use one as a test bed to experiment with and use also as
a tug to pull sand trailer around our complex.
The other one is an old original E-20 with lots of strange (by todays
standards) electrics inside.  Brian a EV friend tries to get me to
upgrade it to a real PWM
instead of the old relays and resistors.
Let me tell you I am almost tempted to do just that.  On www.ebay there
is a golf
cart PWM on sale for a buck seventy five as opening bid and I got one a
while back.
One reason it is cheap "considering" is that it is an inductor input but
.
I got mine to work with fixed resistors from 9 k to 3 k ohms.  I would
keep the micro switches speed control and have a fixed reverse and five
forward speeds along with my reg gear box.   
Also if you wanted to have more speed you can use Trojan T-890's with the
Curtis 1205-211 since it is a 36 volt to 48 volt input voltage unit.  Of
course you would have to 
use a dropping resistor for 16 ohm field if it is   shunt wound  motor. 
Field gets hot with 30 or more volts on it.  
If you use a cruising equipment E-meter then use a zener to drop B+ from
pack voltage to 24 volts to power E-meter.  It can't take more than 39.9
volts supply meter.
A five watt zener does OK at 30 volts on meter input.

Next week I'll remove my 1221B and try the new 1205 and compare speeds
and power.  I do love the speed of using high voltage but range is
limited with small battery pack.


"Russell"
http://www.concentric.net/~russ239
120 volt S-10 Chevrolet,  132 volt E-16 GE, 36volt E-20 GE
jeGra research
D. Russell Graves
P.O. Box 261, Maynard, MA, 01754-0261