Permanent magnet assisted motor coil designs

[captainpecan]

Edited post... I found some math errors. I took down my efficiency test results until I get it figured out better.


I think I went from a possible 128% efficiency to 31% efficiency because i figured wrong.. that's pretty bad... lol. I think I will work a bit more on making sure my efficiency tests are as accurate as possible and start making some huge adjustments to design. The whole concept may end up very inefficient afterall. Hopefully I'm figuring something wrong. Time will tell.

[Floor]

Bad numbers happens some times,  for sure, no big deal.  That's the way it some
times goes when presenting on the fly. When you find that it's the case, just don't
let it bog you down.

[captainpecan]

Ok, I think I have nailed down all my issues trying to figure out efficiency of this motor. It's simple really, the performance just kind of blows as a motor after all. I have now done many tests, and all have came out to between 35% efficient to 38% efficient. I switched my coils to parallel and push more current. It seemed a little less efficient but not much change in percentage. I determined my pulley was way to small and could be making the calculations all messed up converting things. I made one myself that is larger out of an empty wire spool. It still fell within that range. I will post my math just in case someone can see an error I made, but I think I have it correct.
Here is one of my test results with my own diy pulley.
Pulley circumference - 8.625 inches or .71875 feet
Voltage - 16.2v
Amperage - .16 amp
RPM - 562
Work done - 50 grams


Following the dynomometer test I learned from Peter Lindemann in his motor secrets video, here is what I came up with...
16.2v * .16 amp = 2.579 watts
1 HP = 746 watts
2.579 / 746 =
0.003457 Input HP


562 RPM / 60 = 9.36 rev/sec
9.36rps * .71875 (pulley circumference feet)
=6.73 ft/sec
50 grams / 456 (grams per pound) = .1101 lbs
6.73 ft/sec * .1101 lbs = 0.7414 ft-lbs/sec
(1 HP = 550 ft-lbs/sec)
.7414 / 550 =
0.001348 HP Output


Efficiency = Output / Input
0.001348 / .003457 = .389 × 100
38.9% efficiency


If anyone can see an error in how I performed this test, please let me know.

[captainpecan]

Bad numbers happens some times,  for sure, no big deal.  That's the way it some
times goes when presenting on the fly. When you find that it's the case, just don't
let it bog you down.

I agree. Thanks for the response. There is a lot to learn from what I've done here though. I think there is something to this coil design but the numbers show different so far. I have some more work to do learning more about it. It does run really nice amd at very little wattage. It just doesn't put out the kind of torque I was hoping for to go with it. Not giving up on it for sure. I just may need to adjust my perspective and change what I'm doing with it.

[captainpecan]

Another thought. Pulse motors are really never made for torque. I am having a really hard time finding anything anywhere of others doing these actual tests with pulse motors? If anyone knows of a resource I can make comparisons with, please post it. It may be that these results are good for a pulse motor, it's just that I'm expecting more than one can deliver at this low of power usage.


I think i will start tuning it to have the sharpest, shortest pulse possible, and start studying the flyback more. It seems to me that there is extra energy to be had out of these PM embedded coils. I need to change directions I was heading in trying to use it. May be on my way to trying them out in solid state oscillations as well. So much to learn and so many things to try.