RE: (ET) Using 4QD controllers

["Bob Murcek" <rmurcek geisinger edu>]

I have an E12 so I can't try this, but I'm wondering if the efficient 
low-speed control provided by a PWM controller would make it possible to 
just increase the motor pulley size to make up for the top speed lost by 
not doing field weakening.  I.e., with the original contactor control you 
have to run the motor at full speed or lose energy in the resistors; when 
you're using a PWM controller you can run the motor at less than full 
speed at no battery life penalty.  All you'd lose to a bigger motor pulley 
would be some pulling power in 1st...Bob

>>> Humphrey Timothy H Contr AFRL/IFEC <Timothy Humphrey rl af mil> 
>>> 6/5/2003 2:16:28 PM >>>
Yes, and consequently, range(although not much, I believe).

My field weakening is not functioning on my I5. I have the knowledge and
capabilities to fix it, but it's absence doesn't bother me so much that I
feel a need too.  I expect to have a free moment sometime around the summer
of 2014, maybe I'll fix it then. ;-)

Stay Charged!
Hump
I5/NY


-----Original Message-----
From: john briese [mailto:goodguyforsure hotmail com] 
Sent: Thursday, June 05, 2003 12:36 PM
To: roden ald net; elec-trak cosmos phy tufts edu 
Subject: Re: (ET) Using 4QD controllers



So.....If I understand this correctly...(remember the only EE course I 
took 
I got a D in!!)
The 4 quadrant controller will give me reverse, will controll the field 
on/off, but I loose field weakening which will reduce top speed? John 
Briese