Re: (ET) 48v ET

[Christopher Zach <czach computer org>]

> The real problem with raising the voltage is that the current goes high (more or less constant resistance... 
> well, the resistance increases with temperature, the RTD effect) which causes things to get very hot.  It's 
> the CURRENT that produces torque, not the voltage, but you need voltage to get the current up.

There's also the little issue that the parts of an Elec-Trak are rated 
for 36 volts. Bumping things up to 48 may not seem like much, but it 
could eventually weld a contactor. That would be bad.

The other truth is resistance: The wires in an Elec-Trak put a *LOT* of 
resistance under heavy load. I was actually kind of shocked to see that 
my little sensor does not trip the lights when attached directly to the 
battery, but does trip when attached to the other end of the battery 
wires from the back pack forward. There is a volt drop under full load 
there; that's about 100 watts of power wasted into cable.

If you're building a dragster class Elec-Trak, upgrade the battery 
connect wire runs to 4 gauge wire or something really thick. It's a limit.

Chris