> You need an Alltrax control!
I need an Alltrax controller like I need a hole in
my head.
Seriously: The Elec-Trak controller is the model of
simplicity and
logic. I have seven speeds times four gears; that's
enough to get me the
speed control I need. I have regen and braking for
excellent overall
speed control. And I have a little circuit that
measures the armature
current and shuts down the field weakening circuit
automagically when I
overload the motor.
And cruise control with a little light. What more
can I need?
This is not a car, where you want a wide amount of
speed settings. I
have 28 possibilties between 0 and 7 miles per hour.
That's not bad. And
besides, I usually use this thing for constant speed
applications like
mowing the lawn or blowing snow. Having a controller
that never gives me
the same speed twice would be annoying.
There might be a point in the fact the the E15's
controller is a lot
more parsnickety. This appears to be the case; it's
logic board tries to
do a lot of things that the inherent nature of
having contactors does
for the E-20 (there are no timing circuits on the
E20 for example; the
contactors provide the time for you). And the E20
reverses the motor the
*right* way: By reversing the armature with
contactors as opposed to the
field with relay points. The E15 was a cheaper
design, but one can fix
that too with simple discrete components.
So for $5.00 for four diodes from Radio Shack my
controller is fixed.
And will probably last for another 30 years. At
which time I'll simply
replace the components again instead of scratching
my head looking at a
solid-state thingie. I'm sure Radio space shack will
sell diodes in 2034.
Probably the only remaining weak link is the relays.
And to be honest
when they die I could just build a 36 volt to 24
volt power controller
for $5.00 and replace the relays with modern 24 volt
ones. Sealed too.
$25.00 and that's all done for the next 30 years.
There's a place for everything. A contactor
controller doesn't really
belong on a car (like the Renault electrics) and a
digital control
doesn't really belong on a lawn tractor.
As for using the tractor: My E20 is my main mowing
and plowing machine.
The simpler the better. BLDC mower motors are nice,
but it adds
complexity when the omputer blows out.
Chris Zach
Rod Hower wrote:
I plan on ordering one tomorrow.
I know there are diehards on the list that prefer
to keep original equipment, but I will upgrade
mine
to the latest technology. Like others on the list
I plan on using this tractor as a practical
machine
and don't care much about keeping it original.
I would have converted an ICE machine to electric,
but it's much easier to get an Elec Trak going,
even
if it is 30+ years old. My mower deck will use 3
BLDC
motors from work with lots of 'engineering' to
connect
the mower blade. I would have used the original
PMDC
mower motors, but the blade and mounting hardware
were
in very bad shape and required me to dismember the
parts.
I'll post pictures when the job is finished.
Lots of work, but worth the effort since I don't
have
to listen to the gas engine.
Rod
--- Chris Zach <czach computer org> wrote:
Ok, the breadboard is fixed. Basically what I did
was replace all four
of the diodes with good old fashioned 3amp diodes
from Radio Shack. The
larger diodes have a forward voltage drop of .5
volts as opposed to 1.0
volts for the smaller ones. So I took a drill,
enlarged the holes in the
PCB slightly, and soldered in the new diodes.
Put it back in; works like a champ. As a bonus,
speeds 6 and 7 now come
online. Now if I could just get a voltmeter that
*works* and a bulb for
the cruise control switch I would be 100% set for
the summer.
Meantime I will put in an order for 22 ohm
resistors
and the other
oddball types and replace everything in the fall.
Chris
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