----- Original Message -----
From: Seth <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Saturday, October 19, 2002 9:53 AM
Subject: Re: New ADC 11" motor- sepex and series
>
>
> Thanks for the clarification Rod (especially as it applied to ADC
> motors), I know it helped me. Can you or anyone else suggest a text on
> Sep-ex motors and controllers? Also, has anyone here rewound a series
> motor for optimization as a sep-ex?
>
Hi All;
It HAS been done. In my years at Electric Fuel Propulsion, back in the
70's Bob Aronson had a tinkerer buddy, Doug Dow, that did just that. He
rewound the big Series Baker motor in a Mars 2 converted Renault to Sep EX.
Of course, wlectronics didn't exist for this. He did it mechanically, using
a series paerallel aseytup, with a separate field control. The whole outfit
took up where the back seat was, when the car ran it sounded like a
parchinko machine, Pinball, clone, but it did WORK. A bit of getting used to
it and yu could come up to a stoplite pumping a few hundred amps back into
the battery. None of this wussy 50 amps stuff, serious amps! When the
contactors screwed up, it could almost lock up the rear wheels. It was a
hoot to drive, and showed the potential. Doug passed on YEARS ago, but he
would have something to ad to this thread, if he was alive, and he would be
about 100 years old, by now..
This is what turned me on to sep Ex, it did provide almost all the
braking, would fade when yu stopped, of course. Should hook it up to the
stoplites, as this would take the sport out of stopping for,the guy
following you, though!
That's my take on Sep-Ex, why T think that it could give AC a run for
it's money.
Seeya
Bob
>
> Thanks,
> Seth
>
> Rod Hower wrote:
> >
> > Perhaps I should clarify my response.
> > I don't describe things as well as Lee, but I will
> > make things more understandable.
> > When I describe the 'size' of the field winding I am
> > actually explaining the size of the field winding wire.
> > What this comes down to is amphere-turns.
> > The series motor has heavy gage wire that handles
> > the same current as the armature (hundreds of amps).
> > If the field has 100 more turns of much smaller gauge wire
> > it still has effectively the same 'amp turns' as the series motor.
> > The field only needs to handle 1/100 the amount of current to
> > create the same field. This is the major advantage of the Sepex
> > motor, you can electrically reverse and control the field with
> > a fraction of the amps of a series system.
> > This also creates a problem, since you can change the dynamics
> > of the system with 1/100th of the field current.
> > The series system is somewhat self regulating (as long as you have
> > a load!). If you don't control the field current properly in a
> > sepex the system can get destructive real fast.
> > If you don't believe this, check out the ADC website for
> > information on motors. If you specify a sepex they want
> > detailed information about the vehicle and the control.
> > This is why a sepex motor must be designed with the vehicle, including
> > gearing, control and load points.
> > A well engineered sepex in my opinion is much better than a series, but
> > that depends heavily on a smart engineered vehicle.
> > You can always drive a poorly designed series system with low range and
> > efficiency, but if you screw up the sepex design the result could
> > mean a blown control or efficiency that is even worse than the series
> > system.
> > As an example I will compare a Taylor Dunn flat bed vehicle with a load
> > capacity of 1500lbs.
> > Series system;
> > Top speed 24 MPH
> > Load capacity at moderate grade: 1000 lbs
> > Sepex system;
> > Top speed 30 MPH
> > Load capacity at steep grade: 1500 lbs
> > I didn't pull these numbers out of the air, I designed the Sepex system
> > with the same current limit as the series system back in 1995 at GE.
> > Rod
> > �
>
