Paul & Sabrina's cheap DIY 144v motor controller

[isaac_alaska]

oh that sounds perfect. the rev limit right now waits for one second after it hits the limit, and then cuts the power for 1 second, and then re-applies power at whatever the throttle is telling it. so if you floor it in neutral it speeds up more during the one second of power than it slows down durnign the second of no power...and it keeps going faster and faster until it explodes (oops)
can't wait to get it back so i can fix the software haha

[steiner]

jackbauer,

I'm curious.... how are you going to configure Paul's controller to work on a SepEx motor? Do you just have another smaller controller to handle the field?

Thanks....

[okie00]

Originally Posted by MPaulHolmes

I added the push-pull feature in the software so that if a couple pins stop going high and low at 16kHz, the hardware will disable the mosfet driver, since that would most likely happen if the microcontroller crashes. It was just a single line of code that's required to run at 16kHz, so it eats up almost no processing power. I was going to add a "microcontroller_crashed_fault in the code", until I realized, the micro wouldn't know if the micro crashed! hahaha.

I also added programmable max current. the variable is called max-current. haha. You can input anything you want in the range 0-9999 real life amps. That means if you set it to 120, full throttle will be 120 amps. I double checked all the pins to make sure everything is good.

The controller is 99.9% done:

It's 6 isolated supplies, so 6 separate pwm signals that all have their own shielded twisted pair (with ground) cable going right to the input of the respective optocoupler.

I think someone was asking about the schematics. I'll post everything once it's all working. The wiki is seriously jacked up right now though. It's been taken over by a weird spam-bot.

I've got an updated schematic and layout that removes the VERY EXPENSIVE DC-DC converter (like almost $18) which feeds the inputs to the 6 line filters, and replaces it with a homemade DC-DC based on the very popular MC34063A

The careful observer will note that it costs like $0.63 cents. hahaha. The rest of the nick-nacks you need to make it work are another $2-$3 or so.

Thats a very nice looking unit, thanks for all your hard work

What size is the completed unit going to be?
I was looking for a case to put the controller in
what size is the boards and bus bar your using?
What is the max output volts going to be?

thank you

[jackbauer]

Yeh a small power stage (say 50A) is used to control the field power. With Paul's 6 output board this would be very easy. Hint ,Hint , wink , wink

[steiner]

JB,

I was thinking you might use one of those. Are you still going to stay with IGBTs?

[jackbauer]

yep igbts.

[MPaulHolmes]

The 6 pwm outputs aren't independent of each other though. I mean the duty is the same for all 6.

[MPaulHolmes]

Originally Posted by okie00

What size is the completed unit going to be?
I was looking for a case to put the controller in
what size is the boards and bus bar your using?
What is the max output volts going to be?

Hello! The power board is 11.7 x 6 I think. I'm sure about the 11.7 part. I'm at school watching the students take their Final right now. man I'm glad I'm not in school. The base plate is hmm Maybe 13" long and 8" wide? I'm pretty sure, and 3.5" tall I think. bus bars stick out like 1" I think. max voltage is 144.

I've got a sample 400v diode but it only has one really wide leg and I don't know how to put slots in the board. I wouldn't mind figuring that out. That would let me up the voltage some, since good mosfets can be had up to 300v.

edit: forgot bus bars- 1" x 0.25" x 14" I think bus bars. Not sure about length at the moment. 13" or 14". and B- is 3/4" x 3/8" x LENGTH, where length is "I forgot" haha

[jackbauer]

Originally Posted by mpaulholmes

the 6 pwm outputs aren't independent of each other though. I mean the duty is the same for all 6.

doh!

[MPaulHolmes]

But I just finished the AC control board which has 6 independent pwm outputs! hahaha. Just use that one, but with different code.