Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

An electrical engineer offered to send me his fancy breadboard! I think he's mailing it today. It will be nice to have one with SOLID connections. I've been planning the layout of the control section. I have it so that there is only a single path that connects the digital grounds to the analog grounds, and through that path is a ferrite bead. Even though the atheist communist coal burning, um, Tiananmen Square, um, "great leap forward" breadboard was crap, part of the reason things weren't working was because I had some settings wrong on the oscilloscope. hehe. The breadboard still had bad connections, though.

Fran suggested that I have the hardware overcurrent shutdown (HOS) be turned back on by a human at first, since he said the HOS can mask slow response time in the software (because the HOS always works super fast!). I doubt it will come up that much anyway if a person is doing non-jack rabbit driving. The most I've ever used around town is 300 amps. But even if you routinely hang right at the 500 amp mark (or 600 or whatever), the HOS will take care of that. I shut off the mosfets and put in a delay of about 5 cycles each time the forbidden 500 amp mark (not to be confused with the Forbidden City in Communist China) is crossed.

I tested the HOS part on my baby (non-commy) breadboard. I faked the current signal, and it works perfectly! ya!

[MPaulHolmes]

If there are no major problems, I predict a test very very soon. And I mean soon. Not tomorrow, but really soon. I think I'll test it at the bike first at 12v. Hardware current limiting will be set to 500 amps (actually 497 amps I think. The resistors just worked out that way hehe), though, so I doubt I will get a chance to see that part in action. The short circuit current through the motor is only like 50 amps or something (maybe limited by the bike batteries? I used to ride it with an on/off switch and no controller).

After shortening the controller box by a little over an inch, I now have to make it just a bit taller! haha! Man, version 2 is going to be 1,000,000 times easier!

I need to put the emergency big beefy andersen connector disconnect in the car. Not that I think it will be a problem, its just that mosfets fail in a short circuit state (read "full throttle! Won't Stop!!!). Hmm.. I wonder how I know that? And I mean "KNOW THAT!", NOT LIKE I READ IT SOMEWHERE! hahahaha!

So Ben, put an emergency disconnect switch in that car of yours. Assuming the 12v bike test and 72v car test work as they should, and I see no reason why they shouldn't, expect a little present in the mail by the end of the month.

Moment of prayer: Dear God, please don't let Ben die while testing this controller. Amen!

[lawoo]

http://www.youtube.com/watch?v=A7SUJ...e=channel_page

I dont understand much about the video but maybe it will help improve the project.

[bennelson]

I finished my battery box yesterday.

Unfortunately, it looks like the way I will have to go is with 5, 5, and 2 batteries in the middle box, wayback, and radiator position.

I'm now working on wiring up up 72v series/parallel with a design to just swap two cables to convert to 144V.

[esoneson]

Paul,

Fingers crossed and hoping for the best!

Good luck to you, my friend.

Eric

[nubie]

Way to Go!!

. . . . .

I love it, glad you won that t-shirt, I voted for you

[brihoo2k]

Dear god; Please let the motor controller be a complete sucess. Please let it have the ability to go at highway speeds. And god of all things please dont let the mosfets fail and make Ben put in an emergency cut off switch. lol

[blazoner]

He might need a drag-chute to go with that cut-off switch, too....

[MPaulHolmes]

Oh Snap(ing turtle!), a parachute... eBay Motors: Simpson Racing Skyjacker 10ft Red Parachute chute drag (item 200318972795 end time Mar-17-09 19:23:40 PDT)

Oh wait, this won't work... It's only good to 200 mph.

[MPaulHolmes]

I think I'm going to cry! OK, well it was actually a super low voltage test, like 5 volts or something, but everything works perfectly with the WHOLE DANG CONTROLLER!! I haven't tested the current limiting or the temperature cutback. I'll need to put it into the car to get anywhere near 500 amps.

I almost passed multiple kidney stones as I first plugged it in. I almost forgot to connect the power section ground to the control ground. I had a coding error that made the controller do nothing! I thought there was something catastrophically wrong with it. Then I had the stupid dang hall effect current sensor plugged in backwards into the control board! They have it numbered 4 3 2 1 instead of 1 2 3 4! Dorks!

I had gotten an awesome new fancy breadboard that is BIG from Chris, the Electrical Engineer!!! He also sent a bunch of other awesome stuff (electrical components that I will find very useful!). I want to take a picture of the controller, and the power section and weenie board section, but my betteries are dead, and I can't find the dang battery charger!

I already tested the circuit as best I could (sort of) on the breadboard (no bad connections! Take that you commies! hahaha!). Then I METICULOUSLY removed each piece from the breadboard and SOLDERED it to the permanent radio shack ghetto PCB (2 of them actually, since the circuit was too big). I mean METICULOUSLY!!!!!!! I checked each coordinate like 5 or 10 times, and spoke out loud everything I did. I had never made a permanent soldered circuit before. I thought for sure that when nothing worked that I had done something terribly wrong! But it was just a coding error and the backwards plug in thing!

3 months culminating in one moment, and it not working for like 30 minutes is sort of stressful.

Next (tonight??? CRAP!!! i HAVE TO GO WORK AT SYLVAN TONIGHT! dANG RICH PUNKS!) I'll hook up a 12v battery to test it that way, and then skip all that crap and go right to the car. Then I'll go get a ticket from the cops, come right back, do a few more tests over the coming week or 2, making sure the coding is pretty good, and then ship it to Ben! Go Ben, it's your birthday, light a candle, throw a party!