Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

Yes! 144v 500amps! It is a lot of power, huh! But these components can take it.

Atmel AVR Studio

It's a free development environment and C/C++ compiler/editor. Then you just go up and click to program the microcontroller from inside the editor! It's all self contained! It's awesome. I think they do it so you will use the AVR microcontrollers instead of PIC.

I am in communication with a company for a really good deal on diodes. They sell them for $2.36 each, whereas Digikey and Mouser both charge like $5.19 each, and since you need 10 for a 500 amp controller, it is quite a bit of money! It takes like $20 off the price right off the top. I was looking at components, and if people would get kits in groups of 2 or 3, the parts costs are around $250! Isn't that amazing!?

[Blue Bomber Man]

Instant torque at zero rpm? yep =)

Oh ya, zero emissions too!

[MetroMPG]

Paul & Sabrina: congrats, congrats.

Favourite line from the video: "Oh. That was irresponsible."

Don't throw out that old piece of junk controller!

[lectruck]

On Ebay even 36/48v controllers are going for several Hundreds of Bucks. Sign me up for a Modder 144v Controller/Kit.

So everyone with 72v controller don't flood the market all at once, when you get your p&s 144v Cheap Motor Controller.

[MPaulHolmes]

That was my favorite line too. hehe. I finally understand the PI loop! It isn't a loop! It's a chunk of code that gets run every so often! There's no "while", no "for", no nothing related to a loop! It's just a chunk of code that gets run ONE TIME each millisecond or so, and it chases the current! I'm so dang happy I could just go to the bathroom in my pants right now. hahaha! I'll write that dang PI loop tomorrow, and I'll test it in the car soon.

Oh ya... There seems to be a 72v controller being sold on Ebay. Only $350! By some guy named mpholmes8cij... Interesting... I wonder who that is?
72 volt 400 amp Curtis Motor Controller - eBay (item 290304655769 end time Mar-28-09 21:49:34 PDT)

That person must have some way of replacing the 72v controller with a different controller. And maybe he is wanting some extra money to buy some bulk components. Or not.

[MazdaMatt]

Glad you nailed down that detail of the PI controller It doesn't have to get it right, it just has to get *closer*. The system characteristics (overshoot, settling time, etc) describe HOW it gets closer. Obviously you're a more ambitious person than I am, so just post your code or PM it to me and I'll give it a read.

I REALLY want to make a high-end control board for this project... but i just don't have the time. I see so much potential with a better processor and more inputs. What do you think it would take to have seperate inputs for battery voltage, batt current, motor volts, motor current? It would be nice to develope a "console" for it, as well as some SDcard datalogging (with gps, of course )

[MPaulHolmes]

Battery volts: No problem. (well, not a huge problem, details of voltage sag and when to cut back, but not too hard)
Battery Current: No problem. Just add another hall effect current sensor,

or!!!!! You can use the rule:

I_battery = I_motor*PWM_duty.

This gives very good results, according to the EVTech list people. It can be computed inside the microcontroller! No hall effect sensor! Cheaper! ya!

And an input from a hall effect sensor that monitors a magnet that rotates on the motor post, in order to control RPM... In order to have cruise control mode! To protect from over-revving! To um, um, tell you when to shift up or down. It could make clutchless systems easier to find that nice good spot for shifting. I can't think of anything else.

Ya, Ben, with GPS of course (ben really likes GPS).

Ya, I like the data logger idea too. energy usage, money spent driving, time for full recharge, capacity left (taking into account peukert millisecond by millisecond!), um... I can't think of anything else. Oh! Set all the limits that you want from the console. Maybe set current limit, set change in current rate, um... and other stuff.

[MazdaMatt]

Now you're understanding why I wanted to be a computer engineer

If you wanted to get really hardcore aobut this, the open source charger could feed back information on charge current and the controller could actually begin to calculate peukert effect. You'd be able to get a constant 'state of charge' meter that is actually accurate.

future planning... for now, just try not to kill ben.

[bennelson]

Selling your 72V controller!?!?!

Man, you are confident.

That also means I will have to give back the 144V controller to you when I am done testing it! No Fair! My secret plan all along was just to keep it, because the next one you build will be so much better anyways, why would you want the original back!

Anywho - good luck to whoever buys the 72V controller. That one really is a very nice 72V unit. (But I am biased, because I have the EXACT same one in the Electro-Metro!)

[MPaulHolmes]

Ben, you can keep the controller! I am making a new one. I hope to finish it in time for the May 2 Lacey alternative energy fair. The pressure's on! I haven't even started it yet! yikes. maybe I should wait to sell that controller. hehe.

Matt, that's an awesome idea about the peukert effect! Battery companies don't exactly advertise that number.

Yes, yes... Don't kill Ben... Must focus on that right now.

Isn't it weird! type something on the computer,

i = 2, oops I mean i = 20. and ben hurtles down the street, out of control! hahaha!

My wife and I are signed up for a motor control conference in Seattle on May 11. That should be fun! We are going to miss the DC control part, but they will have all the latest stuff with AC control. It's free too! ya!