> 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 theparts. 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 didwas 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 forthe summer. Meantime I will put in an order for 22 ohm resistorsand the other oddball types and replace everything in the fall.Chris _______________________________________________ Elec-trak mailing list Elec-trak cosmos phy tufts eduhttps://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak _______________________________________________ Elec-trak mailing list Elec-trak cosmos phy tufts edu https://cosmos.phy.tufts.edu/mailman/listinfo/elec-trak