Re: (ET) New controller suggestions

["David Roden" <etpost drmm net>]

Alltrax makes a controller specifically designed and programmed for the 
E15. 
 I have one on my E15 and it's quite satisfactory.  I believe it can also 
be 
used on other ETs with wound field motors.  I don't think I'd try to use 
it 
on an ET with a permanent magnet motor though - I think I recall reading 
that it gets confused or may even be damaged if the field output isn't 
connected to anything.

Others have used different options.  At least one (former?) member of this 
list adapted a Curtis series motor controller intended for golf cars.  
These 
require some method of powering the field so it is properly energized when 
the armature is powered.  Also, they require a certain minimum amount of 
motor inductance for the current limit to work reliably.  (If the current 
limit doesn't work right, starts may be jerky, and the contoller may fail 
from overcurrent.) The ET motor may need a series inductor to provide 
enough 
inductance for a Curtis, though I'm not sure about that.

At least one other person on this list used a 4QD controller for a wound 
field motor.  I believe I recall that he used the brake release output to 
control field power.  I have his posts on this filed away somewhere, but 
don't have time to look for them now.

The 4QD is probably a good choice for ETs fitted with PM motors as that is 
its intended application.  I have one here for my New Idea rider, but 
haven't gotten round to installing it yet.  This summer has been WAY too 
busy.

Bottom line is that the E15 and Alltrax is the only existing "plug and 
play" 
solution.  Others will require a modicum of expertise and understanding of 
EV and electronic principles to implement.  An experienced EV hobbyist can 
probably figure it out, but I don't know that I'd trust a golf car 
workshop, 
as my impression has been that their mechanics mostly swap out "black 
boxes" 
without necessarily knowing what they do.


David Roden - Akron, Ohio, USA

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