Paul and Sabrina's Cheap 3 Phase Inverter (AC Controller) with Field Oriented Control

[rapapar]

Hi guys.
I'm a simracer and I'm working on an AC brushless motor for direct drive steering wheel.
I think that this project could be good to drive motor following input from ush hid device (force feedback device on computers)
I have an usb part already working, I would add your project to do this way: CarSimulator program => usb FFB signal => firmware part to catch FFB strengh and direction (force of steering respond from the simulated car) => your librairie firmware part to drive the AC motor => your electronic circuit for amplification => motor

could it be possible anyway?
Sorry for that "intrusion" here, but I'm looking everywhere to find a solution and I think your projet would be the best to do that. Isn't it?

thanks

[e*clipse]

Originally Posted by MPaulHolmes

No this is the 6kw 480vac motor at 120vdc bus. I am waiting on payday to order an encoder for the brushless dc motor. I tested the brushless motor by spinning the post and looking at the waveform on the oscilloscope. It looked very sinewavish so it will be fun to test it .

Paul - the motor should run in open-loop mode (just to get it spinning)

What's the shaft diameter of that motor? I'll see what I can come up with for an encoder. What resolution do you need?

Perhaps I can do a resolver - or is that too much different stuff at once?

I just got my hot air soldering station and some paste. I should be able to get those boards together now. Sorry, I don't have cts casemod's patience for hand-soldering little stuff. Just getting those few parts on the bottom was a chore. It didn't help that I didn't include thermal vias to the ground plane. That ground plane is a very effective heat sink!

- E*clipse

[e*clipse]

Paul,

Nice work getting this motor working!

Does anyone know of a display system (some sort of digital dashboard) that could use this data flow?

On a semi-related note- I have this pump project that I'm trying to keep as low-tech as possible. Paul, Thingstodo - could this work open - loop > no feedback. The pump motor is an induction 3 phase AC 240 V machine that right now is just plugged into the line.

Would Paul's open loop control work? What (minimum) things should be added to make this pump more usable - right now all the owners want is a simple knob - twist control, but it seems some sort of water pressure feedback would be be awesome.

- E*clipse

[MPaulHolmes]

The post is 0.875", but right where the encoder would go it flares out to 0.882", but I can probably sand it down a bit or something. I've heard 64 ticks per rev is good. I'm using 512 at the moment. You can run it in open loop no problem with this.

[e*clipse]

Hot air rework

WOW - this thing really works!

I just tried removing two 1210 resistors and replacing them with ferrite beads, using the E-bay air rework station. - model 852D+.

It works GREAT! Thanks a zillion Astro! Paul - this is definitely worth the money! (I paid about what Astro did)

The parts come off much easier - they're even reusable after removal, where I would often break stuff in my attempts to remove them using a soldering iron.

Regarding soldering - Astro's write up is spot on. The learning curve isn't bad at all.

Mine has a little oscillating air pump in the main box, rather than the handle. It's a bit noisey, but NBD. I have the air turned all the way down to reduce moving components.

Oh, and regarding solder paste - the stuff needs to be refrigerated. Be prepared for extra shipping costs for 2 day delivery, just for the solder. At the same time, a flux pen is "hazardous material " and must be shipped ground.

- E*clipse

[thingstodo]

Originally Posted by e*clipse

On a semi-related note- I have this pump project that I'm trying to keep as low-tech as possible. Paul, Thingstodo - could this work open - loop > no feedback. The pump motor is an induction 3 phase AC 240 V machine that right now is just plugged into the line.

Would Paul's open loop control work?

A pump works well with open loop control.

What (minimum) things should be added to make this pump more usable - right now all the owners want is a simple knob - twist control, but it seems some sort of water pressure feedback would be be awesome

The 'volume control' speed control should be all you need .. depending on what Paul has implemented on open loop.

Paul - what does the 'throttle' map to in open loop - hopefully output frequency or rpm? Or did you get that far in your experiments? It sounded like you had not spent much time on open loop.

If the potentiometer is set up for 5V at minimum speed and 0V at maximum speed, a pressure sensor that puts out 0V to 5V for 0 - 100 psi would replace the volume control and regulate to a pressure. The pressure MAY be able to be regulated with a potentiometer in series with the pressure sensor. It would take some experimentation with sensors and potentiometers.

[e*clipse]

I'm having trouble finding something that will fit over your, um, big shaft that doesn't cost $$$$.

Suggestions for my searches?

Originally Posted by MPaulHolmes

The post is 0.875", but right where the encoder would go it flares out to 0.882", but I can probably sand it down a bit or something. I've heard 64 ticks per rev is good. I'm using 512 at the moment. You can run it in open loop no problem with this.

[MPaulHolmes]

Originally Posted by e*clipse

I'm having trouble finding something that will fit over your, um, big shaft that doesn't cost $$$$.

LOL. Haha.

The cheapest I have found is $145 for 1, and $100 each for 5. But I don't need 5.

[Astro]

Originally Posted by e*clipse

Hot air rework

WOW - this thing really works!

I just tried removing two 1210 resistors and replacing them with ferrite beads, using the E-bay air rework station. - model 852D+.

It works GREAT! Thanks a zillion Astro! Paul - this is definitely worth the money! (I paid about what Astro did)
...

852D+ Then you bought the same model as me. I think they updated it just after i bought it but didn't change the model number. They added a few refinements. Fan in the main unit is different to mine. Bet you even got a real power switch?

[MPaulHolmes]

Originally Posted by rapapar

Hi guys.
I'm a simracer and I'm working on an AC brushless motor for direct drive steering wheel.
I think that this project could be good to drive motor following input from ush hid device (force feedback device on computers)
I have an usb part already working, I would add your project to do this way: CarSimulator program => usb FFB signal => firmware part to catch FFB strengh and direction (force of steering respond from the simulated car) => your librairie firmware part to drive the AC motor => your electronic circuit for amplification => motor

could it be possible anyway?
Sorry for that "intrusion" here, but I'm looking everywhere to find a solution and I think your projet would be the best to do that. Isn't it?

thanks

Oh it's no intrusion! I think it would work fine. I'm not 100% sure I understand, but as long as you somehow tell the controller the amount of torque you want it to produce, it will do it, as long as it's hooked up to a motor.