Re: (ET) Curtis or any generic controller setup - Finally.

["David Roden (Akron OH USA)" <etpost drmm net>]

On 3 Aug 2012 at 3:13, Robert Troll wrote:

> I just wanted to do this because some people said it would not work and
> others said it should but did not know how.

Just wondering who said this.  It wasn't here, was it?

It's been a few years, but I've read posts on this very list from others 
who 
have used Curtis series motor controllers successfully.  We had similar 
discussions about the "gotchas" then, too.

I'm not a EE, but I have a moderate amount of electronic and electrical 
tinkering in my background.  I can follow a schematic but don't know much 
about the finer points such as PC board layout and lead dress, for 
example. 
Even with that limited background, I would probably have hacked up 
something.  However, the Alltrax showed up before I got round to trying 
it.  
That seemed like a much easier and faster answer and I haven't regretted 
it.

One of the characeristics of a sep-ex motor is that it really should have 
a 
controller properly matched to its field requirements.  The Alltrax ET in 
fact has a table in its firmware that maps field current to pedal position 
(and maybe to other operating parameters too, I don't know).  

You could do something similar with a generic controller by plotting what 
the GE field controller does (it's pretty simple) and duplicating it.  In 
fact I have a vague recollection that maybe someone did just that, using 
the 
stock speed lever to connect various resistors to the potbox input of a 
golf 
car controller, and leaving the GE field weakening resistors in place.  Of 
course this doesn't take full advantage of the variable speed a modern 
controller provides, but it does still eliminate some of the troublesome 
parts of the GE controller.

My gut suggests that if you decided to "roll your own," a 4QD or other PM 
motor controller would be a better match to the ET than a series motor 
controller such as Curtis, or one of the cheap Chinese imports such as 
Kelly.  But as I said before, I've heard (right here) of others 
successfully 
using series motor controllers, so more power to you!