Brushless Servo commutation chips

[JiriK]

unterhaus, did you check your motors for the phase coil arrangement?
I checked mine, and all four were like I previously described, two phase coils between pins A-C and B-D.

I´v been looking for a chip that could perform that commutation..
LM621 from National Semiconductors (NSC) might be one, but seems like it´s no longer available. So, current plan is to let Microchip Pic18F4331 do the commutation.
(And possibly step/dir drive of the motor) I guess it could do a lot more, but I don´t have enough programming skils.. Yet.
So LM629 controller from NSC will perform the PID functions.

[wotje]

Originally Posted by JiriK da21, please build a prototype brushless motor driver I´m not the only one who has this kind of motors.. Back to the chips, I have some NSC LMD18245´s here. They contain some of the needed high power circuits, including a PWM- current control etc. But they just don´t have enough capacity for these motors I have (3A vs 6A) I wonder.. Are there other similar devices that have same kind of logic & control circuits like in LMD18245´s but with driving circuits for external power devices?

That is not a problem. If you need a 6 amp driver then you can connect 2 LMD18245 parallel together and you have a 6 amp driver. And if you need 9 amps then just take 3 LMD 18245

On this side http://www.sb-microstep.nl/Nederlands.htm you find 2 stepper drivers one is 3 amp en one is 6 amp. But the 6 amp is a 3 amp with a 3 amp extension. In the pdf files from these drivers is a schematic how that is made. It is quit simple. I build myself a 6 amp based on this principe but instead of the microprocessor they used I used a pic.

[unterhaus]

Originally Posted by JiriK unterhaus, did you check your motors for the phase coil arrangement? I checked mine, and all four were like I previously described, two phase coils between pins A-C and B-D.

That's the way mine is too. I'm totally stumped. I don't think the 4 phase drivers I have seen make sense for this motor.

[wotje]

This is what I found on those DUNKERMOTOREN type BG63 and BG83.

http://www.dunkermotor.co.kr/download/BG_43_E.PDF
see page 13 "block diagram BGE 2406 A"

The DUNKERMOTOREN electronically-commutated D.C.motors have a fourphase electromagnetic motor winding designed as a complete coilpackage inserted into a quadratic stator plate with grooves.
The permanent-magnet system of the 4-pole rotor consists of radially staggered magnets (neodymium magnets BG 43, BG 63 S and BG 83 S; ferrite magnets BG 63 and BG 83) to reduce the cogging forces.
The signals transmitted from two Hall sensors and a sensor magnet are the basis for position identification of the rotor in relation to the rotary field to be generated.
Electronic commutation is executed by means of bipolar selection of the 4-phase-motor winding by employing 8 transistors in the output stage.

The 1-quadrant electronic controller BGE 2406 A, which contains the electronic commutator and a speed regulator, is usedto control the BG 43x50 and BG 63x55 series motors.
As 4-quadrant electronic controllers, the BGE 4010 A and BGE 4010 A are available.
The BGE 4010 A is above all employed to control the BG 43x50, BG 63x55 and BG 63x55 S series motors, whereas the BGE 4010 A is mainly used where higher power is required, for example in connection with the BG 83x90 and BG 83x90 S series motors.

And from this discription I understand that it is a 4 phase motor. On the other hand, you only measure 2 phases.
So I thought, is it not possible that there are electronics inside (for example capacitors) the motor who prevent you from measuring the other 2 phases.
And for that reason they work perfect in combination with the originel controllers.

Its not more then a thought.

[JiriK]

This is what´s inside of BG63..
Images were taken by Pentti U. who has a bit different motors.. BG63´s
with gears and without brake or encoder.

[wotje]

As you can see on the first picture. There are 4 coils, you can see it on the 8 big solder points round the hole. Four solderpoints of them are 2 by 2 connected together. And if it is a double sided board, then you can presume that the other 4 solderpoints are conected at the same way.

That declares why you only can measure between a-c and b-d.
The coils in the motor are connected in the same way, as in a unipolair stepper motor in paralel mode.
I don't no how I can put a picture from the schematic over here.
And I think you have to aproach this motor in a kind of way as bipolar stepper motor.
With a LMD 18245 or something like that.

I looked at the datasheet from a LS7260, but for this moment I don't see how you can drive this motor with that IC without making any changes to the motor..

But it is a funny motor. I sleep on it this night, perhaps I get a better idea.

[JiriK]

Wotje, The board is double sided.
You mean a bipolar stepping motor with 4 phase coils, of wich two and two are connected paraller? I´m familiar with stepping motors.

I finally browsed to the end of the motor datasheet, and found the commutation truth table. One 360deg mechanical revolution includes 4+4 electrical steps.
So, a big bipolar stepping motor with 45deg step angle and hall sensor feedback.. Funny motor, indeed.

A while back (like a year ago) I got those Maxon EC-motors wich are 3 phase brushless motors with three Hall sensor signals. As an excercise I made a motor driver using discrete FETs and a PIC16F84. The rpm of motor wasn´t fast, but I got it spinning... Very educative project.

Does anyone know stepper controller chips that meet following requirements:
(other than LMD18245)
* Bipolar drive
* External power devices supported
* PWM current control with a DAC onboard

[wotje]

Originally Posted by JiriK Wotje, The board is double sided. You mean a bipolar stepping motor with 4 phase coils, of wich two and two are connected paraller? I´m familiar with stepping motors. Yes. By a regular bipolar motor these coils are in series connected, but in this case they are paralel connected. This gives more speed. Does anyone know stepper controller chips that meet following requirements: (other than LMD18245) * Bipolar drive * External power devices supported I don't now exact what you mean here. * PWM current control with a DAC onboard

Perhaps a Alegro A3955 or Toshiba TA7289P or F