Joe Leger
3rd April 2020, 18:32
Looking to make my first 12v PMA.
Checking out different sized neo magnets and magnet wire. Will probably end up with a fairly typical 9 coil, 3 phase setup. that seems to be the sweet spot. Keeping the 3:4 ratio i may scale to 12:16 on a later iteration if i get there.
I do not have any specific measurements for rpm or exact air/water flow rate etc, i live in an apartment do itll nostly run on a bike, best i can get for a # is that my default pedal rpm when i ride an exercise bike is 90rpm i seem the land there even as resistance changes up until i cant keep going. I want to take it camping and run it on a water wheel in a creek and tinker on etc. So only parameters i have is my needed voltage of 13.6-18ish to go into a charge controller and my baseline pedal rpm of 90rpm which i can gear up easily from 1:1 to 4.1:1 or about 360rpm with common sprocket sizes and i can regear to suit a creek
That said, l need a baseline setup.
Seems like a lot of people say 18-20 gauge wire as a typical layout but the coil winding count ranges pretty wildly.
Magnets are plentiful for options. the ones i was looking at seem to balance size price and power reasonably.
Something like a n45 1.5 or 2" x .5 x .25 can be had for under $2ea or n52 1.5 x .5 x .25 barely over $2
Which brings me to my first question...
Is it more beneficial to use 24 magnets on 2 rotors, we'll say the n52 1.5x .5x .25 w/26 lb of pull which are 2.19ea or $52.56 total
Or 1 rotor with 12 considerably more powerful magnets with or without a blank steel plate on the opposing side?
Say 1.5x x.75 x .5 w/56 lbs of pull which are 3.56 a pop or $44.72 total
There is more combined power in the 12x thicker ones. But is the dual rotor still more efficient even with slightly less combined overall magnetic strength?
Checking out different sized neo magnets and magnet wire. Will probably end up with a fairly typical 9 coil, 3 phase setup. that seems to be the sweet spot. Keeping the 3:4 ratio i may scale to 12:16 on a later iteration if i get there.
I do not have any specific measurements for rpm or exact air/water flow rate etc, i live in an apartment do itll nostly run on a bike, best i can get for a # is that my default pedal rpm when i ride an exercise bike is 90rpm i seem the land there even as resistance changes up until i cant keep going. I want to take it camping and run it on a water wheel in a creek and tinker on etc. So only parameters i have is my needed voltage of 13.6-18ish to go into a charge controller and my baseline pedal rpm of 90rpm which i can gear up easily from 1:1 to 4.1:1 or about 360rpm with common sprocket sizes and i can regear to suit a creek
That said, l need a baseline setup.
Seems like a lot of people say 18-20 gauge wire as a typical layout but the coil winding count ranges pretty wildly.
Magnets are plentiful for options. the ones i was looking at seem to balance size price and power reasonably.
Something like a n45 1.5 or 2" x .5 x .25 can be had for under $2ea or n52 1.5 x .5 x .25 barely over $2
Which brings me to my first question...
Is it more beneficial to use 24 magnets on 2 rotors, we'll say the n52 1.5x .5x .25 w/26 lb of pull which are 2.19ea or $52.56 total
Or 1 rotor with 12 considerably more powerful magnets with or without a blank steel plate on the opposing side?
Say 1.5x x.75 x .5 w/56 lbs of pull which are 3.56 a pop or $44.72 total
There is more combined power in the 12x thicker ones. But is the dual rotor still more efficient even with slightly less combined overall magnetic strength?