RaserTech, brushless power from induction... - RC-Monster Forums

zeropointbug · 12.09.2006, 07:53 PM

yah, i think square wire is harder to spin/make. i don't think it would work in a motor cuz of all the twisty turnings, you dig...

Would you know anything about using Bifilar in motors by any chance? BrianG

BrianG · 12.09.2006, 08:01 PM

Quote:

Originally Posted by zeropointbug

yah, i think square wire is harder to spin/make. i don't think it would work in a motor cuz of all the twisty turnings, you dig...

Would you know anything about using Bifilar in motors by any chance? BrianG

Yeah, the twisties would be a bit difficult to negotiate, but if the winding was done by machine, it could be done I think.

Yes, I know what Bifilar means, but in which way? There are several ways they can be connected; Straight parallel connected pair, series connected pair but parallel wound, parallel but opposing directions, etc?

I've also wondered at what inductance these motors have. If the inductive reactance value is too high, compared to the pure resistive, it may be "difficult" for an ESC to drive. Has anyone heard of a capacitive correcting netork that would help bring the voltage and current in phase, which would make the ESCs job easier?

zeropointbug · 12.09.2006, 08:57 PM

Do you mean motor starting capacitors? Like that have a relay to disconnect when up to speed?

Has anyone heard of the Halbach array? It's magnetic sequence where each subsequent magnetic is turn 90' from the next, and this cancels the field on one side of the array, and magnifies it on the other side. A small company (couple guys) made a BL motor for solar races and it used Halbach array, the motor had a full load efficiency of 98%. WOW.

Also, can someone explain the Neu motor codes... like what does 1515 1/Y mean?

BrianG · 10:56 PM

Quote:

Originally Posted by zeropointbug

Do you mean motor starting capacitors? Like that have a relay to disconnect when up to speed?

Has anyone heard of the Halbach array? It's magnetic sequence where each subsequent magnetic is turn 90' from the next, and this cancels the field on one side of the array, and magnifies it on the other side. A small company (couple guys) made a BL motor for solar races and it used Halbach array, the motor had a full load efficiency of 98%. WOW.

Also, can someone explain the Neu motor codes... like what does 1515 1/Y mean?

No, not starting caps, but caps to cancel the negative phase angle of current vs voltage due to the inductive reactance. Really, power factor correction. Before this thought went any further, I did some reading and found that you definitely should not use caps when the motor is being driven with a veriable speed controller, which our BL motors are. I guess that ESC designers, knowing this, probably take this into consideration somehow when designing the circuits, or maybe simply don't care.

I'm sure there is all kinds of technology out there just waiting for application in our BL world, but there must be reasons why it hasn't been done yet. Cost, complexity, comparatively low market penetration of BL equipment, etc.

I've also wondered at the Neu motor codes, but simply don't know. The 15xx and 19xx series motors are 15.6mm and 19.6mm in diameter, respectively. That seems to be a pattern until you get to the 22 series, then it falls apart since those cans are 2.5" in diameter. The last two numbers in the model seem to be related to can length. No conversion per se, but 1512's are 2.4" long, 1515's are 2.7" long, etc. But then the same last two digits mean different lengths for other series motors. I assume the "D" and "Y" stand for Delta and Wye, which is simply the coil configuration. But the number is puzzling but it seems to relate to the number of turns, but not the actual amount of turns. The lower the number the lower the turns/higher the KV.