Okay, I'm 6 months late on this one...
I haven't looked at the physical placement, but, could a second
switch be put in place on the brake pedal that engages at the top of
the pedal travel, and applies the 'reverse' input to the controller?
Then, small pedal travel on the brake causes reverse selection to
slow the tractor, limiting pad use; further travel applies pads; max
travel gives "stop now" functionality described below.
Comments?
After nearly 2 years, I'm finally getting around to putting my
controller in.
Been busy, but part of the reason was laziness to source the
resistor and diodes in the diagram.
Now, after reading some back-postings, I find people are installing
fuses. Are these really necessary? And why one each on the Pins 9
and 10, when just one is needed on the other size of R1 ?
-Chris
----- Original Message -----
From: Mike Wallace
To: ralphgv talkamerica net ; Archive, Elec-Trak
Sent: Friday, February 24, 2006 12:25 AM
Subject: Re: (ET) Alltrax install!
Ralph said,
"A while back several people (including me) wrote in about the
brakes grabbing when we tried to slow down a little bit. Now I see
it is the motor that is stopping us. I have a steep hill in back of
my house with no way to go around it. The tractor speeds up going
down, and when I touch the brake pedal I slow down for about a foot
then the wheels lock up. The tractor tears up the grass and will
start sliding sideways, very scary."
How many of you guys have the brake switch adjusted to open as
soon as the pedal is moved down ever so slightly? I think this
might be your problem.
Originally, I think GE wanted the brake switch to act as a "kill
the tractor in a panic stop situation", not every time you just
barely pushed the pedal down. I kinda looked at it as the "wife's
switch", as in when she wanted to stop but still had her right foot
on the speed control pedal on my WH C-185.
This scenario is even more likely when applied to the large frame
tractors with the dash mounted speed control. In an emergency/panic
like situation, it's a lot easier (and more natural) to mash the
brake pedal to the floor than to reach for the speed control lever
on the dash.
I may not remember our exact phone conversation all that well as
it was probably close to two years ago by now, but I think Steve
Richardson had his brake switch (on an E15 with dash mounted speed
control) adjusted "your" way because he never knew how it was
supposed to be adjusted. Check out Paragraph 1.15 BRAKE SWITCH
ADJUSTMENT on page 1-24 of the Home Owner's Service Manual.
I personally think the brake switch should still be adjusted to
open just before the brake pedal bottoms out on the footrest. Try
it and I think your hill problem will go away.
Mike in KY
----- Original Message -----
From: Ralph & Elaine Vogan
To: Archive, Elec-Trak
Sent: Thursday, February 23, 2006 12:59 PM
Subject: Re: (ET) Alltrax install!
David Roden (Akron OH USA) wrote:
I have that very diagram right here on my computer. If you need a
copy, you
can download it from here :
http://www.alltraxinc.com/old/Manuals/DCX-ET%20Manual.zip
Thats the same one I have. My old eyes didn't notice the power
bypassing the main relay though the 1 ohm resistor
According to the diagram, those safety switches connect to the KSI
(keyswitch) input of the controller (6th pin from the left), not to
the main
contactor.
Yes, but turning off one of these switches should turn off the B+
to the main contactor coil
Battery voltage on the KSI terminal enables driving current from the
controller.
Any time the main disconnect is on, battery + is also applied to
the 8th and
9th pins (designated logic B+ and B+ power respectively). These are
supplied from a tap *ahead* of the main contactor. The main
contactor coil is
powered by an output from the controller, not directly by the
keyswitch.
I thought the main contactor was connected to B- through a timer
in the controller.
Those pins (8 & 9) are specifically intended to be powered *even
when the
KSI terminal is not* so the controller can stop the tractor as
quickly as
possible under the following circumstances -
1. the brake is applied
2. the keyswitch is shut off
3. the operator leaves the seat
It uses plug braking to do that. I have experienced this effect on
my tractor.
If I want it to stop quickly, I just turn off the key or touch the
brake pedal.
The braking effect is quite pronounced!
A while back several people (including me) wrote in about the
brakes grabbing when we tried to slow down a little bit. Now I see
it is the motor that is stopping us. I have a steep hill in back of
my house with no way to go around it. The tractor speeds up going
down, and when I touch the brake pedal I slow down for about a foot
then the wheels lock up. The tractor tears up the grass and will
start sliding sideways, very scary.
If yours doesn't behave this way, either you didn't wire it
according to the
diagram, or plug braking has been disabled in your controller. I
think you can
disable plug braking with the PC control program if you want to, but
it's been
quite a while since I ran that program on mine, so I'm not sure.
I don't want to disable the plug braking on the seat and key
switches, but I need a finer control of the foot brake. Do you
think putting the brake switch in series with the throttle switch
would allow the motor to coast then I could control the level of
braking with the pedal and brake pads?
I may be wrong, but my understanding of plug braking is that it does
not
actually apply reverse current. Rather it maintains the field
current while
short-circuiting (or nearly so) the armature. This stops the motor
very
quickly. If I'm wrong about that, I certainly welcome correction of
my
misapprehension from the designers of the Alltrax, the designers of
any other
plug-braking controller such as a Curtis, or those who have studied
plug-
braking controller design.
I agree, but plugging means to turn yhe field on & off to control
the rate of braking. To bad our Alltrax doesn't work that way.
Ralph