Can anybody recommend any 6-step commutation BLDC motor controller ICs; I can't use a microcontroller or DSP as this is a safety critical application which precludes the use of software.
I'm considering UCC2626 from TI, however, I really need something with synchronous rectification. I'm not that familar with motor control so any help would be much appreciated.
I don't keep close track of available-off-the-shelf motor-controller IC's, so I don't know if what I did about 15 years ago for Bosch... electronically commutated simply by sensing winding voltages, is available as a standard part. Hall effect sounds _way_ expensive to me.
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
"The American Republic will endure until the day Congress
discovers that it can bribe the public with the public\'s money."
- Alexis de Tocqueville
That kind of controller requires some sort of feed back on the angles. If you look at the docs, it talks about HALL returns. those are HALL pick ups that report back as to where the rotor is.. This in turns allows the controller to help maintain the position of the rotor to stay in sync.. I don't know if that is what you're referring to how ever, it maybe what you're looking for.
A/C fan motors for Mercedes don't need precision positioning, just be very quiet, even during acceleration/deceleration... and not run backwards even when driven by wind ;-)
...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
"The American Republic will endure until the day Congress
discovers that it can bribe the public with the public\'s money."
- Alexis de Tocqueville
Hall sensors are very cheap. Normally they are mounted in a group that slightly offsets the index notches.. this allows for the drive controllers to jokey the the rotor in place. Most of the time they are mounted internally, synchronized with the stator windings so there is no problem with alignment at installation time. They make 2 varieties of motors for this application. a normal induction motor and a motor with a PM in the rotor. the PM has much more torque at lower speeds while other does not but deals very good at higher RPM's..
Today's technology now uses Vector Feed back system which is just a AC motor with tightly laminated bonded windings with a larger rotor in many cases and potted heat sinked cases for heat extraction. When operated in the "Vector Close Loop mode" via (Q encoder), these units can step down to very fine moments if so desired and lock them self's into position.
It's a cheaper alternative to other expensive precision controlled motors.
Ok, I'll keep that in mind when I'm driving my Hyundai! :))
Toshiba TB6575 and others from this "family", sensorless...
hth
- Michael Wieser
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