Paul & Sabrina's cheap DIY 144v motor controller

[bennelson]

Originally Posted by MPaulHolmes

Only the right side of those gate to source resistor legs were vaporised. The left side was essentially unharmed.

I will work harder at vaporizing legs symetrically next time!

[MPaulHolmes]

That's what I want to hear, Ben! ya!

Hey! I started etching the power section of Ben's replacement controller. I'm using a 9"x6" piece of double sided 4 ounce PCB purchased by Wherewolf! ya! It's really nice stuff. It lays very flat. Sometimes PCB bows out, and it's really annoying.

[MazdaMatt]

re: turning on far mosfets first... Interesting concept. You're in the realm of R&D when you get into that kind of fractional microsecond tuning, though. However... the "garage hack" version of this could be to simply put your gate driver right beside the furthest one and let the trace inductance do its thing. You'd "maybe" get a "tendancy" for the ones closest to the driver to charge first.... but do you want the ones closest to the bus bar to turn off last?? way to complicated for forum banter to give you any useful information, methinks.

Paul, I would love to review the schematics and layouts as they are being produced. I have only been doing this computer engineering thing for a couple years professionally, so I love to learn from the experienced pros and add my insight where I can.

[Tango Charlie]

Paul, thanks for any and all pictures you may post. Does your camera have a 'macro' setting? It may help the autofocus dial in on things closer than three feet away.
This project rocks!
Go, Paul, go!

[~JdOwNj]

Just wanted to pass along some Kudos for an incredible project. I completed the survey, and eagerly await building my own

[MPaulHolmes]

Thank you JDOWNJ! Your user name would make an excellent password. Tango Charlie, I really don't know how to use our camera. I really would like to learn, though. I'll see about finding a macro setting. A guy from new horizons (the electronics distributor) is coming down to bring the 30 free samples of the diodes that are usually like $5 each! Now, I'm no mathematician, but 5*30 is a lot. These have a very low voltage drop, and I think are the perfect diode for the 144v 500amp controller. I'm also experimenting with the RURG8060, which has greater heat loss, but may allow for a bit more current. The new horizons cost is like $2 each for the diodes in bulk! Way cheaper than mouser or digikey!

I'm going to try to finish the etching for the power section today, finish drilling the holes in it on friday. Then, maybe friday I'll try to drill the copper heat spreader too.

Then, I can solder the mosfets/diodes/gate resistors if they are here. Oh crap! They will arrive next week. OK, so I'll solder them next week. Then I'll solder the capacitors. That's pretty quick and easy. Then the power section will basically be done. Then, once the control section is done, we can even have a professionally made one done? I would like to do a breadboard test also. Then I'll solder the components on the control board, and then make a dang box, and then attach the heat sink, and then test it in the car, and then mail it to Ben! We'll figure out what needs to be different if anything, and then order more control boards, and then start beta-testing.

[MPaulHolmes]

Well, I finished drilling and etching the power section PCB. I now know that I should always do it in a particular order, and I need about 7x8 or 7x9 instead of 6x9. grr! I had to do a bit of maneuvering on the back side, so it looks a bit wiggly, but it will work just fine. I'm not worried about it's function, just its form this time. It's really annoying! Sorry Ben. But it will work just fine, so don't worry. It may just not be something that you want in a transparent box. haha!

[Hondo]

Hey Paul, I might be able to help in the box dept. My company has a plastic dept. where we vacuum form plastic parts out of 3/16" thick black ABS. I don't know how much heat the box would need to stand, but the ABS we use gets soft at around 260 degrees. It would be very easy for us to make a block mold the size the controller would need. It would just have to have a little taper from the top to the bottom to get the mold out once the box was formed. We could then leave a flange on the bottom to attach to a bottom piece. I don't know if it would work or not but the cost would be cheap. We could probably get 4 boxes out ouf a piece of plastic that cost $8.

Hondo

[MPaulHolmes]

Hondo, holy cow that would be awesome! Let's talk once I figure out the dimensions.

[esoneson]

Paul,
You mentioned in another thread that you were putting in 12 mosfets and diodes in Version 2. This is great! 776 amps, safely....... Hope they all fit 'cause that's what I was going to do anyways. Yowza!
Eric