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

["Jim Coate" <lists freerangeelectric com>]

On closer look, Rod's schematic is for a special case where he would keep
all the original micro-switches and the Curtis would go in "steps" rather
than infinitely variable speeds. So the solution all depends on your
needs.

To Robert, that center-off may just cover it. Devils advocate: try
flipping that switch really fast and see if the Curtis picks up on the
brief "off" time. If so, good deal.

Yes, my store does sell the Alltrax line, both the "special" ET version as
well as the "regular" versions.
But... I was answering from the perspective of an engineer who likes to
look for possible failure modes (what I think you asked for?), which makes
my wife think I'm a pessimist, but I'm not. Really.
I'd still be curious to see your diagram (e-mail address above) to try and
fully understand it.

Now to chew on what others have been saying about PM vs series type
controllers.




> The DPDT switch is center off.
>
> Forward - field on - relay 1 opens - controller turns on - armature
> powered.
> Center - field off - relays off - controller off - armature off
> Reverse - field on and reversed - relay 2 opens - controller turns on -
> armature powered.
>
> Also "high pedal disable" on the controller makes that scenario
> impossible. When changing from forward to reverse the controller turns 
> off
> then on. If it senses anything from the POT it will not energize the
> armature. You must turn the POT back to zero before you can proceed.
>
>
>> 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.
>
> The goal was safety, universality, simplicity, cost. I recd many 
> different
> designs and looked them all over carefully. Most were just conceptual.
> Nothing solid saying do XY and Z. And the ones that did were above the
> average joes ability to create. That is what i wanted to do. Take the
> mystery out of it and help some people bring back some tractors from the
> dead. If my curtis blows up tomorrow i can replace it with a kelly, or
> 4qd, or alltrax. Well actually it came with a two year warranty so i 
> would
> probably get it fixed.
>
> If i ever used field weakening then i might have gone the sep-ex route.
> But i don't and wonder how many people do? Not supposed to use it while
> doing heavy work right? That in itself is a whole other ball of wax that
> has been beaten to death. What i plan on doing is adding a simple "turbo"
> mode by wiring a resistor into the field that i can turn on when i want 
> to
> zip across my yard.
>
> I understand that you sell the Alltrax. I understand it was purposely
> designed for the ET. Will probably buy one off you for my E15. I will be
> the first one to tell people that if you want a brand new controller
> designed for the ET that is supported by the manufacturer please call 
> Jim.
> I just wanted to do this because some people said it would not work and
> others said it should but did not know how. I had fun and that's what 
> this
> hobby is all about.
>
>