Paul & Sabrina's cheap DIY 144v motor controller

[MPaulHolmes]

Is it possible to upload a larger picture? I am waiting on my glasses still. It looks good though!

[MPaulHolmes]

Yes, you need a pretty pointy soldering tip. Just don't run around with it, or you might get stabbed in the eyeball and get lead poisoning.

My update is that I don't have any updates. Well, I believe I can do synchronous rectification. The details are always the hard part, but it really makes sense to me. Soon, I'm going to try 3 mosfet drivers with 9 of the new 230 amp mosfets, and 9 of the 230 amp mosfets acting as freewheel diodes. Then the diodes will finally not be the limiting factor. The legs of the 230 amp mosfets can handle 160 amps of current. It's crazy. The TO-247 PLUS package they call it (or you could use TO-264). I think 750 amps is very reasonable in that setup.

[MPaulHolmes]

The 10v you are talking about is from Gate to Source, which makes sure that the mosfet is turned on. When it is below like 4v, the mosfet is turned off, and above around 4v, the mosfet is turned on. So, the datasheet used 10v from gate to source just to really make sure it was turned on. When the mosfet is turned on, the current from DRAIN to SOURCE can be 230 amps, and the resistance from DRAIN to SOURCE (RdsOn) is 0.0075 Ohms. However, the 9 mosfets would be on at the same time, so it would be NINE 0.0075 Ohm resistors in parallel, for a net resistance of 1/9*0.0075.

The mosfets don't really care what the pack voltage is (up to a point) since all that really matters is RdsOn and the current through the mosfet. If you stay clear of 200v, you are just fine! So, if you have a 120v system, the mosfet doesn't care at all. If you have a 12v system, the mosfet doesn't care.

Let's say we are pushing 80 amps through each mosfet. Then the voltage drop across each mosfet is 80*0.0075 = 0.6v. And the heat dissipated in each mosfet while it is in the ON state is 80*0.6 = 48 watts. Crap! What is this, a dang toaster oven?! OH well...

[jackbauer]

I'm going down the igbt route myself. Going to start off with 4 off 150amp 1200v modules with the high side gate tied to emitter and use the high side as the diode. If that works out i'll bump it up to 2 off 600amp modules with water cooling.

Paul the parts arrived "in country" yesterday but have been held up by customs. I guess they need the extra money to build more morgue space after the plane crash

[MPaulHolmes]

How irritating! I think the IGBT route will work great.

[squiggles]

Just another thought for the diode. More convenient than multiple parallel devices.

http://www.microsemi.com/datasheets/...0U40G-Rev1.pdf

[bennelson]

I just installed my Open Source Controller - The Cougar 2 - in the Electro-Metro.

I haven't blow it up yet!

Read more in my thread.
http://ecomodder.com/forum/showthrea...tml#post126422

[MPaulHolmes]

If you replace the mosfets with:
Digi-Key - IXFX180N25T-ND (Manufacturer - IXFX180N25T)

The diodes with:
http://www.fairchildsemi.com/ds/RU/RURG8060.pdf

And the caps with:
Digi-Key - P11641-ND (Manufacturer - EET-ED2E681CA)

You would have a 180v 700amp controller. Totally plug and play! hehe. I love powering a controller with 12v.

[apowers]

I got the controller working in the truck today. It is very smooth.
Much better than the homemade controller I was using. I don't have
anthing else to compare it to. This is the only EV I have seen in person.
I took it down the road and back a couple of times,about two miles,
and when I opened the hood the controller was barely warm.
Thank you very much Paul
Alvin

[MPaulHolmes]

Alvin, you are going to make me cry! Cut it out!

Awesome Job!!!!! You are the man!