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Re: (ET) Elec-trak Digest, Vol 14, Issue 109

It really surprised me when I first learned that the ET doesn't do 
armature reversing (at least mine doesn't), since a DC motor control 
system is already designed to handle rapid changing of the current in the 
armature.

I'm not sure off-hand which capacitor (I think on card 1) controls the 
time delay, it's been a while since I looked at the diagrams. If I were 
designing a time delay circuit for this with active analog components, I 
would probably just use a simple RC circuit (resistor in series with 
capacitor) with a diode and relay together in series, which is in parallel 
with the capacitor. Choose the diode's forward breakover voltage and the 
values of R and C such that the capacitor will charge up and reach that 
breakover voltage after the desired time delay, then allow current to go 
through the relay. Can't remember if that's how GE did it or not.

>From what other's have said, the Alltrax apparently automatically does 
>gradual dropping of the current, so they have resolved it that way.

Mike


________________________________
Michael S. Briggs, PhD
UNH Physics Department
(603) 862-2828
________________________________

________________________________________
From: RJ Kanary <rjkanary consolidated net>
Sent: Saturday, August 27, 2016 9:28 PM
To: Briggs, Michael; et
Subject: Re: (ET) Elec-trak Digest, Vol 14, Issue 109

             Some do, some don't. The ones that use armature reversing
contactors do not fall victim to that illness. :)


RJ


On 8/27/2016 9:18 PM, Briggs, Michael wrote:
> David,
>
> Since the Elec-Trak reverses direction by reversing the direction of the 
> current in the primary coils of the motor, wouldn't instantly reversing 
> direction while under load cause a significant back EMF spike that could 
> fry some electronics? Doesn't the Elec-Trak have a time-delay circuit to 
> prevent that from happening (and as the capacitor in the circuit fails 
> over time, it allows instant reversing, which leads to frying the 
> reverse relay)?
>
> Mike
>
> ________________________________
> Michael S. Briggs, PhD
> UNH Physics Department
> (603) 862-2828
> ________________________________
>
> ________________________________________
> From: David <d_erskine att net>
> Sent: Friday, August 26, 2016 4:38 PM
> To: elec-trak cosmos phy tufts edu
> Subject: Re: (ET) Elec-trak Digest, Vol 14, Issue 109
>
> Re: Speed Controller
>
> I would like to add several thoughts to the topic of installing an Altrax
> controller.
>
> I took several weeks to thoroughly understand the wiring on my E-20 
> before
> tearing into the conversion. I tagged every wire and noted their 
> connection
> on a spreadsheet. This paid off in that I only made one wiring mistake.
> I led all the Altrax’s signal [low amperage] wiring to a barrier strip.
> [Actually, I used two multicontact barrier strips in that I also lead all
> the original ET signal wiring to another, easily accessible multicontact
> strip.]. This makes trouble shooting much easier.
> I had to lengthen several existing signal wires, wherein I used insulated
> butt crimp splices. If I had it do over I would use European style
> connectors, wherein the stripped wires are inserted in insulated metal 
> tubes
> and held by set screws. This, I feel, makes wire splicing easier [and 
> easier
> to make corrections], more secure, and allows for continuity testing.
>
> As noted previously, the main attribute of the electronic controller is 
> the
> infinite speed selection. This drastically reduces the need to change 
> gears.
> The far more efficient controller reduces drain on the batteries; making
> them last longer for any given chore.
> But, to me, the most usable attribute is the totally different procedure 
> for
> changing direction of the tractor. I now can slowly pull right up to an
> obstacle, with my hand on the forward/reverse switch, and immediately
> reverse direction – without fear of damaging the traction motor. This is 
> so
> handy that I no longer use the brakes.
>
> cheers, David
>
>
> -----Original Message-----
> From: elec-trak-request cosmos phy tufts edu
> Sent: Friday, August 26, 2016 12:00 PM
> To: elec-trak cosmos phy tufts edu
> Subject: Elec-trak Digest, Vol 14, Issue 109
>
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> Today's Topics:
>
>     1. Re:  speed control (Tim Faulhaber)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 26 Aug 2016 07:36:18 -0400
> From: Tim Faulhaber <timfaulhaber gmail com>
> To: Dean Stuckmann <dstuck lakefield net>
> Cc: "elec-trak cosmos phy tufts edu elec-trak cosmos phy tufts edu"
> <elec-trak cosmos phy tufts edu>
> Subject: Re: (ET) speed control
> Message-ID:
> <CABapE+FU5a6F7b5kbDjBmYcfd72f+opvjJpchk7rmo_4U4GKKA mail gmail com>
> Content-Type: text/plain; charset="utf-8"
>
> I've got an ALTRAX just sitting waiting to be installed in my E15.  If 
> you
> could include me on any emails you send out with your install info please
> include me on it.  Maybe it will motivate me to get moving on this 
> project!
>
> Thanks,
>
> Tim
>
> On Thu, Aug 25, 2016 at 6:36 PM, Dean Stuckmann <dstuck lakefield net>
> wrote:
>
>> I installed one in my E-16 this spring and I?m glad I did. I wish I had
>> done it years ago.
>>
>> It was a bit of a project to design the throttle linkage as I wanted to
>> maintain the stock hand throttle along with its built in reverse 
>> switching
>> (no separate toggle switch). I also wanted to have the same speed in
>> reverse as I have moving forward even though the reverse gate is so much
>> shorter. I?m happy to report that I achieved all my goals. The motor
>> control is amazing!
>>
>> However, there are a few things to keep in mind.
>>
>>   - I found that there are multiple installation diagrams out there, and
>> that they are not all the same. (Some specific to the E-20 but not the
>> same
>> either). If the 200 is compatible you may be in better shape than i was.
>> Jim was helpful getting me through it though.
>>   - You are probably looking at closer to $600 by the time you add the
>> throttle pot, HD contractor, and other misc items.
>>   - Field weakening is available in the Alltrax but it is turned off by
>> default. When its off, the ground speed is reduced by around 35%. That 
>> may
>> not make a difference to some but I?m probably going to go to a 4? motor
>> pulley (3? is std) to speed the tractor back up again. You can program 
>> the
>> controller to engage field weakening, but its an all or nothing setting.
>> Its a bit harsh when engaging, and more so when disengaging upon 
>> throttle
>> back. I tried it out, but immediately turned it back off. It would be 
>> nice
>> if the Alltrax/pot could gradually apply the weakening.
>>   - When I installed the controller I mounted mine upside down so that I
>> did not have extend the high current leads.
>>   - The controller does not seem to hold back the motor on down hills as
>> good as the old setup but its not bad. Just something to be aware of.
>>
>> Again, I glad I did it. I?m no electrical wiz but with some time, Jim?s
>> help, and lots of triple checking, I had it working on the first try.
>>
>> I don?t think that I can post pictures or videos of my install on the 
>> site
>> but I can send them to interested parties if you want.
>>
>> Good luck!
>>
>> Regards,
>>
>> Dean A. Stuckmann
>> 5432 County Road U
>> Newton, WI 53063-9624
>>
>> 920-901-2288
>> dstuck lakefield net
>>
>>
>>
>>
>>
>>
>>> On Aug 25, 2016, at 12:49 PM, Jim Coate <lists freerangeelectric com>
>> wrote:
>>> The E20/EGT-200 are good candidates for the conversion. I will (re)send
>> the installation guide and other information to you directly this 
>> evening.
>>>
>>> On 8/23/16 10:32 PM, RAY via Elec-trak wrote:
>>>> Has anyone installed an ALTRAX electronic controller in their tractor?
>>>> i have "nursed" my EGT-200 for quite a few years, and finally I have
>>>> only two speeds left.  I'd like to get a controller , but wonder how
>>>> difficult it might be to install.  The Electric Tractor Store sells
>>>> them
>>>> for $400 plus. I wrote and them and asked if i could purchase the
>>>> installation plan first, but got no answer.
>>>> Any help?
>>>>
>>>> raymondws aol com <mailto:raymondws aol com>
>>>>
>>>>
>>>> _______________________________________________
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