Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

Make sure you get an emergency disconnnect switch at least for during testing, since mosfets fail short circuited. I'm not saying there will be a problem, but you know, just to be safe. haha!

[Daveedo]

A picture of a giant frankenstein circuit breaker mounted to the dash just popped into my head

[MPaulHolmes]

haha! That would be perfect. Ben, you should add one of those. That could be the contactor. Each time the switch closes, an evil recorded laugh should play over the car's speakers. It would really scare passengers.

[bennelson]

Heck, if my wiring doesn't scare passengers, nothing will....

[MPaulHolmes]

I uploaded the text file of the coordinates of where to drill through the PCB, and where to etch it. One picture is for the bottom side, where the capacitors get soldered, and the other picture is for the top side, where the mosfets/diodes get soldered.

The JPG files are set up so that if you print them, they will be the exact size of a 8"x7" PCB. It's possible to use a 8"x6" board with some of the capacitors hanging over the edges at the top and bottom. I might do that, but then the coordinates would need to be shifted up a bit if you are doing some sort of CNC milling. If you are just pressing the ink directly onto a PCB, then who cares! haha!

The squares in the second picture mean that you have to shave off ALL OF THE COPPER INSIDE THOSE SQUARES! YUCK! That's the trials of using 2 sided PCB!

The third picture you can use if you aren't using 2sided PCB. You can avoid all that dang shaving of copper! That sounds good!

Here's a cool utility that I've found useful! This Circuit Width Calculator and it seems to be OK with 3 ounce copper, as long as you aren't drag racing at 1000 amps or something, so I think 3 ounce will be fine.

[Dangerous Dan]

I have just finished reading all of the links on the design and implementation of this motor controller and am thoroughly impressed. We are also working toward open source designs and will post our progress on chargers.

[bennelson]

Paul,

I weight tested my Metro today with 144V of batteries in it.

The brakes are fine with it, but the suspension isn't happy.

120V of batteries is better. I will be able to do 12 batteries if I put in some beefier rear suspension and shift more of the weight to the front.

Neon Tom also has plenty of matched small batteries I could use to build a custom lower amp/hr higher voltage pack for testing the controller.

[nickfarmer]

Great project.

I will look forward to using it in my EV, I'll start a build thread when I get the car (hopefully next week).

[MPaulHolmes]

Originally Posted by Dangerous Dan

I have just finished reading all of the links on the design and implementation of this motor controller and am thoroughly impressed. We are also working toward open source designs and will post our progress on chargers.

That's awesome, Dan! Thank you! We need a good cheap charger.

[MetroMPG]

I love it: mosfet Emma, Jake and Little Miss Muffet. Be careful!

Originally Posted by bennelson

I weight tested my Metro today with 144V of batteries in it.

The brakes are fine with it, but the suspension isn't happy.

I test fit only 2 more (EDIT - correction ... 4 more) 6v floodies in the back of the ForkenSwift, and it wasn't happy on the stock suspension:

Can you say SQUAT! Click in, it's pretty funny in the big image.



But Ivan and I both agree we don't want to give up the rear seat.