Paul & Sabrina's cheap DIY 144v motor controller

[MetroMPG]

Originally Posted by MazdaMatt

I'm starting to think DIY here, but time/budget aren't there for me right now. I would love to develop a DIY 3-phase AC igbt-based controller.

I think Craig McM is probably reading this thread and may be able to comment, but there's a member of the Ottawa EV group who has done a DIY automotive AC controller (not Craig, but he's probably got a better grasp on the technology than me).

He built an inexpensive AC Geo Metro conversion with regen, and has built an AC system for his riding lawn mower. He occasionally demonstrates the latest iterations of his controllers at the meetings.

I don't know enough about the technical details, and didn't pay a lot of attention to how he did it though.

[motor_control]

Originally Posted by MetroMPG

He built an inexpensive AC Geo Metro conversion with regen, and has built an AC system for his riding lawn mower. He occasionally demonstrates the latest iterations of his controllers at the meetings.

Any links ???

[MazdaMatt]

Thanks, Metro. If he's documented anything online, i'd love to read through.

[orange4boy]

Wow. Fantastic piece of work! Beeeaaayyyooooteeeeful!

Just found this tasty piece of controller porn for you electronics fetishists. It's a destructive teardown and reverse engineer of an inverter module from a Prius.

EEK! Naked Transistors!

One of the transistor/diode pairs up close and personal.

Makes me feel like a pre pubescent boy seeing naked lady parts for the first time. A mixture of curiosity and confusion and perhaps a little nausea.

A little dainty compared to your gorgeous hunk of copper though.

[MPaulHolmes]

So, I have a sheet of plexiglass, and I've broken a few small mill bits already trying to cut out pieces for a box. I don't have a band saw. Is Lexan easier to mill? One of my mill bits has a big hard glob of melted plexiglass at the end of it. It seemed to work better while going slower, but it still didn't work very well. It's starting to make me mad! ya! Any suggestions on making a dang box?! grr...

I'm also almost done with the control circuit! ya! almost!

Also, my dang school books and ungraded tests and stuff like that got stolen out of my car today (right at my house!), because they were inside a laptop briefcase thing. I think people thought I had a laptop.

[motor_control]

You may use air or liqued cooling I think.

[MazdaMatt]

I've only ever cut plastics with a saw... band saw or table saw...


Your students must have been trying really hard to fake sympathy for your loss! *re-test*!

[Blue Bomber Man]

With a steady hand a dremel can cut lexan, but the wrong bit will just melt it as it cuts it though.

Though even melting it as you cut it isnt all that bad, just makes for an annoying bur around the edge that usually will break off or can be cleaned up with the dremel on another pass.

[MazdaMatt]

Heavy sandpaper gets rid of the burr and a buffing wheel smooths it to a nice shine... I remember that from grade 7 shop class (13 years ago!)

[MazdaMatt]

Paul, I was looking into prototype board costs and found a website called PCBcart (PCBCART, Prototype to Production PCB supplier from China).

They are based in China and made INCREDIBLY low-cost circuit boards. I punched in a quote for a 300mmx400mm (12"x16") board with 140um (4oz) copper, double-sided.

With a 15-day turn-around, they will produce a SINGLE board for 87 bucks! The best part is, the vast majority of that cost is "setup fee" which you only pay 1 time no matter how many boards or how many orders you make. It is crazy how little they charge for each additional board. 5 boards were 45/ea (including setup) and 10 boards were 40/ea.

So if 5 people were interested in making copies of this controller, it could be done for 45/person. No routing required. No drilling required. Plated vias, double-side copper.