Smart Drive Motor / Generator Build Log

[Jim Mac]

I will show where I am at with the build and offer a little more explanation..

First, understand the primary of a transformer supplies the fluctuating magnetic field that induces the secondary..  I have made several solid-state circuits with 90 degree shifted waves that LOWER input when connecting a load..  But this is a problem!  Lowering Input results in the primary having LESS magnetism and LESS Flux.  

Now with a rotating Permanent Magnet Rotor, the MAGNETS become the "primary" field..  So if I manage to create a circuit that Lowers Input with a rotating rotor, the Magnets are still the same strength, but can now rotate quicker or with less input needed to rotate them.    Therefore, instead of the input lowering the magnetic flux of the primary (like a coil primary does), the quicker magnet rotation Increases the Flux going into the machine. 


So I NEED to make a magnet generator that can output Decent power  + I need it to also output 2 phases 90 degrees shifted from each other..

So here is where I am at:

   

FOUR N52's that are 40mm X 20mm..  These suckers are very strong..  They will rotate between 2 stators on either side of the rotor..  And as you see, the 4 holes on each stator are shifted by 45 degrees.  Now each stator will have a separate phase, and should be 90 degrees apart.  

I have made a similar generator with 4 of these magnets and comparable coils, which produced decent output with only 1 stator..  So 2 stators should do rather well as it will have even more output..  

I need to ensure the output under normal operating RPM's is enough to keep the rotor in motion under no-load conditions.  SO I will need to first Free-wheel the rotor with open circuit output to measure the required power to sustain that RPM unloaded.  Then I will need to load the generator to ensure it can produce at least that amount of power while loaded..  Without getting to that point- the build is worthless..  

SO I print the bobbins now, hopefully tomorrow I can have this thing going

[Jim Mac]

So here is 1 completed stator..

   

500 turns per coil, 2000 turns per stator.  Notice the next stator, how the coil holes are shifted.  Each stator will create it;s own AC phase, and they should be shifted 90 degrees..  Now I can take those 2 phases and work with them, possibly rotating them in a 2nd non-moving setup.  

I am not quite sure where this will go,  but I know I wanted a 90 phase generator for a while now that can output atleast a few watts..  (enough to rotate the unloaded rotor) So hopefully this will do it

[Jim Mac]

Not too bad...   Here is single coil Phase Tests..



This is only watching 2 coils to see the phases..  My gaps are a little off resulting in slightly different amplitudes, but the phase looks spot-on..  I may end up redesigning the stator / bearing stands for more support.  

The output should be pretty decent once I hookup all 8 coils..

[Jim Mac]

I had to back the cores out 6 mm and use a rather large gap because way too much cogging..  But even so,  Not Bad!

I have all 4 coils on each stator in series, forming 2 output phases..  Each phase at 17 Hz gives me around 25V VRMS. I can get over 50 Volta per phase when I crank up the motor. I can't check current properly because when I short 1 output, the rotor comes to a stop..    But viewing the current on wind-down, I believe I am over 1/2 amp per phase shorted (at least).  So I should definitely have some watts..

And the Phases looks PERFECT..

   

   

So I feel I have enough output power to experiment and get some real data!  So I plan to experiment with different configurations with the 90 degree phases on output.

[unimmortal]

Great result Jim, and somehow you've managed to test the one configuration I haven't tried on the Axial yet - which I'm going to now have to test.

You've gone small with the cores, once you start to get over half the magnet width, the cogging will start to diminish.