Experiance with DIY brushless dc controllers?

[DennisCNC]

If you built a regular brushless dc motor controller with hall feedback I would like to know what ic you used and your results, please?

Or if you know of a site that might talk about building one share the link, please.




Thanks

[epineh]

Ordered and recieved a couple of Motorola MC33035's with the intention of having a try, but that is as far as I got, it is now #4575 on the "to do" list

I only posted as you may like to have a look at the chip...

Russell.

[DennisCNC]

It looks like a simple chip to work with. I'll order a few also. I just need a simple controller to go forward reverse and change speed.

Thanks

[epineh]

No prob let us know how you go.

Russell.

[Al_The_Man]

There is also a couple of Motorola app notes, one being AN1046 which may be usefull.
BTW Motorola semi. is now Freescale.
Al.

[DennisCNC]

I also came across this PIC kit:
http://www.microchip.com/stellent/id...cName=en024213
It's $130.

I don't know if I will be able to make one feature work that just realized I need on the regular single chip controllers.

The controller needs to accelerate the motor and maintain speed set by the pot or pulse input but never decelerate. For instance you turn the accel pot up to full speed when motor gets to full speed and stays there and if you turn the pot all the way to low the motor needs to just coast naturally to the new setting of the pot and if you decided to turn the speed up again the controller needs to catch the motor as it's decelerating and accel to the new setting.
The motor will be driving a heavy load, it will be slowed by other means this way there will be less stress on the motor and controller.

[Al_The_Man]

You didn't mention what power motor/drive you need? Do you already have the motor?
If you need a standalone combination, pot controlled, then you could use a standard type drive in Velocity mode this requires feedback, digital or analogue from the motor in order to maintain a constant speed, otherwise the speed will vary with load.
Another possibility is a 1ph in VFD controlling a 3ph motor with encoder or pulse generator feedback, with feedback a VFD can be quite precise.
Al.

[DennisCNC]

Al,

I was messing with a vfd that I have it has sensorless vector control and I connected it to a allen bradley ac servo (~1.5kw) but it was acting a little weird it would slip a lot. The vfd has two pages of setting for the control parameters but I didn't go through all of them.
Have you used vfd's that run permanent magnet motors with some kind of feedback like hall sensors?
For now I want to start with a smaller motor around ~1kw and latter try to control some bigger ones.

[epineh]

It does sound like a VFD would be a better solution for you, you will have to go through all the parameters and set any relevant ones. The VFD's we use at work will accept encoder feedback (I think most new ones will these days) and use a PID loop to control the response, as Al mention's they are very accurate.

Our VFD's have an automatic tuning function when using sensorless vector mode, and some motor's just won't work using this mode.

There also should be a max voltage output you should check so you don't exceed the servo's voltage rating.

Cheers.

Russell.

[DennisCNC]

I bought two of these brushless controllers, they run LS7262 ic's.

I doing more reading on the VFD manual to see what feedback device it likes. This is the vfd i have:
http://www.kimatek.com/orion.html