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

[Rod Hower <rodhower ameritech net>]

Jim is correct, my posting was intended for information only and it will 
work 
using proper ramp up
for field current etc. (I think, never tested :-)
That's why I posted the disclaimer about using the Alltrax, in my opinion 
that 
is the easiest and cheapest route
to upgrade to a new controller and it has worked quite well on my E15.  
The only 
reason I designed the control in the posted
schematic is that I'm an engineer and a real cheap-skate :-)  I had all of 
the 
parts free!,  from pulling parts at work or getting
free samples.  I have lots of 'free stuff' in the basement and will try to 
utilize them in the effort to save money and 'recycle'.
However, there comes a time when it's not worth my effort and it's just 
easier 
to pay for the simpler design.
Rod


----- Original Message ----
From: Jim Coate <lists freerangeelectric com>
To: elec-trak cosmos phy tufts edu
Sent: Thu, August 2, 2012 8:58:08 PM
Subject: Re: (ET) Curtis or any generic controller setup - Finally.

There are a couple of issues when using a "regular" controller (ie meant
for a series wound motor) with an ET that has a sep-ex motor. One is that
you need to make sure the field has power before turning on the armature
power. It sounds like you have done this.

Another is to make sure the armature is off before changing direction.
With a simple switch to reverse the field, it would be easy to be hauling
along with high current in the armature and then hit the reverse switch so
the motor will then try and change direction rather dramatically. A 300
amp controller might limit the current enough to avoid breaking stuff or
doing wheelies, but can't be sure. As in could get scary or dangerous.
Without a schematic I can't be sure, but don't think you have this
covered. (please do send the wiring diagram to my e-mail above)

>From a very quick look at Rod's paper design on a small screen, it appears
he has covered both. Possibly with a control lever that goes from
forwards, through zero, and then to reverse, like the original E15 lever?
I need to print this out and read it more carefully.

Is your goal really an "easy" controller set-up, or "inexpensive"? If easy
is the ultimate goal, you may find it hard to beat a controller build for
sep-ex motors (be it Alltrax, Curtis or another manufacturer). Then you
just connect the two field wires to the controller terminals. It takes
care of ramping the armature current up and down when changing direction.
It does the housekeeping for making sure the field is always energized
first.

However if your goal is actually least expensive, then it all depends on
what random parts you have at hand and how much spare time you have.


>
> I have a full wiring diagram with parts list available for anyone who
> wants one.
>



_______________________________________________
Elec-trak mailing list
Elec-trak cosmos phy tufts edu
https://cosmos.phy.tufts.edu/mailman/listinfo.cgi/elec-trak