Paul & Sabrina's cheap DIY 144v motor controller

[flores]

Originally Posted by thingstodo

Besides my just being nosey, I'm looking for an open source DC controller kit. Perhaps ... maybe ... I could (with much difficulty) roll my own but it's SO MUCH easier to start with a kit!

Since the 1000A works, and I have the igbt version on the way... I have an assembled and working 500A for sale.. would you be interested in that?

[thingstodo]

Originally Posted by flores

Since the 1000A works, and I have the igbt version on the way... I have an assembled and working 500A for sale.. would you be interested in that?

Yes! I'm not too proud to buy one that has been put together by someone else.

The interesting portion of Open Source for me is that I don't have to bet that a specific company will be in business for the next 5 - 10 years. With schematics, bill of material, and documentation I can likely get it fixed (by me or by others if necessary)

Amsterdam to Canada shipping might be a bit expensive ... ?

[flores]

Depends totally on the weight, I will weigh it and check it tomorrow..

[MPaulHolmes]

The 1600uF capacitors were $299 each, so I ordered 3 of the 1000uF ones. That should be fine. They only had 2, so hopefully it doesn't take too long to get the 3rd one shipped. Also, I got the copper sheet. Since the capacitor mounts on top of the IGBTs, the copper sheet doesn't have to be bent, and their dimensions are around 12" x 9" and 11" x 9". Still taking in feedback from the evtech list for changes to the control board and driver board before sending them in to be made.

[flores]

Maybe a stupid question, but:

The capacitors in the mosfet version are 820uF each, right? And there are 16 of them.
How can be one 1000uF be enough for the igbt version?

[flores]

Originally Posted by flores

Depends totally on the weight, I will weigh it and check it tomorrow..

Oh.. it's 6.1 Kgs btw.. so with packaging a 7.5 KG I guess.
That will cost 58 euro == 82 us$ on shipping

[jedsmd]

Originally Posted by flores

Maybe a stupid question, but:

The capacitors in the mosfet version are 820uF each, right? And there are 16 of them.
How can be one 1000uF be enough for the igbt version?

The manufacturer discusses the design differences between the ring capacitor and aluminum electrolytic capacitors here:

Power Ring Film Capacitor Technology | SBE Inc.

What I could get from it is that the inductance and internal resistance of the ring cap is very small compared to the standard capacitor bank. This allows the ring capacitor to be more effective and a lower capacitor value can be used.



It then falls on Paul to make the connections to the capacitor very low resistance/inductance also.

[64jeep]

I made a 3x 400A IGBT controller that uses 3x of the C4DE capacitors at 150 uF each. 2300+ miles and it's still working!

[MPaulHolmes]

Holy cow that's one heck of a blog. I'm going to be checking on that regularly. Thank you for being so thorough! There's a lot of great information that you are sharing. And I saw a code sample of yours too. Very clear and good variable names. Usually, other people's code is hard to read for me.

All beta testers, the stray inductance is related to the area of the current loop and the rate of change of the current. Since there's not a lot we can do about the current changing fast (since it's PWM), you make the loop area as small as possible. Well, two sheets of copper connecting the IGBTs to the capacitor, separated by a thin sheet of nomex (or whatever) make a tiny area. And the noise "squirts" out the sides, but since B+ and B- are so close together, the noise window is just a tiny sliver. It's like how wide the window is open at my house when the temperature outside is below 80 degF (my wife gets cold easy).

[thingstodo]

Originally Posted by flores

Oh.. it's 6.1 Kgs btw.. so with packaging a 7.5 KG I guess.
That will cost 58 euro == 82 us$ on shipping

Thanks for checking.

So .. how much do you want for the assembled controller, with shipping?