Conversion Part 2

[Peppyy]

I discovered that the magnets can be set in to the armature and removed, or at least shuffled with a bit of trial and error.

I attempted a couple configurations of magnets and had some results that were surprising until I turned the motor at higher RPM. Of course the best configuration is the one I haven't yet tried

With 2 poles of 4 magnets each I could spin the genny @ 2200RPM and barely make 13 volts rectified DC. 2 poles of 12 magnets was up to 40 volts and 2 poles of 20 magnets brought it up to over 90VDC.

This is with the main windings wired in series, through a full wave rectifier bridge and no load. I found out that you have to spin the armature @ 2500+ rpm to throw a magnet and it amazingly didn't hurt a thing in the motor. Just a bit of the nickel coating scratched up on the mag. It would be nice to have a tach to figure the cutin speed in series and parallel.

Tomorrow I plan to test with all 48 magnets but not until I find a decent pair of gloves. That armature really wants to jump into the center of the motor and I almost got bit badly last time by the fan blade. I also just realized while typing that my meter has a frequency setting if I can learn to read Russian. Good thing Hertz, Volts, Ohms and Amps are universal.

[DanG]

Usually the composite magnetized material under the scratch & dings has stress fractures that take awhile to become dislodged & noticed - put a good sealer coat over coating flaws ASAP as little granules of neo material will be popping out, especially after 6 months of air exposure...

[ghurd]

""That armature really wants to jump into the center of the motor ""

I cut the top and bottom off a 2-liter pop bottle, cut the side, slid it in the stator.  Like a giant funnel.

The rotor slides into the stator quite smooth and easy.

Also FAST, meaning the motor can jump up to meet the fingers.

But it stopped beating up the magnets and wire.

G-

[Peppyy]

I am pretty sure that I get the most power with 20 mags per pole and a row missing between. Turning the motor by hand with all the magnets in place makes it feel stiff in comparisom and I think I got higher readings with ony 40.

I had no luck reading frequency with my meter so I am guessing,(By trying to count fast) that it is about 4 turns per second or 240 rpm before I hit 14vdc at no load. It may be 300 if I it is 5 RPS so I have to give this some serious thought to weather this will produce any power in a low wind area.

[finnsawyer]

You can calibrate the frequency meter yourself, if you want to do some circuit design work.  Get a filament transformer (60 or 50 hz, whichever applies to you).  Run its output through a full wave bridge to a resistor.  This gives you a pulsating dc at twice the basic frequency.  You now have two known frequencies you can measure.  If you want more frequencies, amplify the bridge output to get a square wave.  You can then make a tuned circuit with a capacitor and inductor (and a simple transistor amplifier) to pick off any of the higher harmonics (240,360,etc. hz).  Or you could do this step with the 50 or 60 hz output.

Another way to do it would be to use a crystal oscillator of known frequency and count down (divide) its frequency to get to the range of interest.

Or borrow a frequency meter and use that to calibrate yours.  cheers.

[Peppyy]

Latest information and a few photos.

Here is all I have to test with at the moment

The drill is only a cheep 1/2" from sears and the best I can turn the genny with a battery attached is about 8 amps. As the drill heats up and the old dead battery begins to take a charge my drill keeps slowing down. as close as I could figure rpm with my meter, at 1080 I had 23.96 volts @ 7 amps for about 175 watts.





I decided that some automotive paint would seep in beside the magnets to help hold them in place and protect them from the elements.

The final wiring turned out to work best with both coils in series. I soldered and heat shrank the leads together. the other 2 were the start winding which were isolated and shrink wrapped.





Gotta love dollar store paint. This is a GM blue from plasticoat.

I picked up a couple of these meters from goldmine electronics for a couple bucks each. Should work good with one for charge and one for load. Already have my 12v stereo up and running in the shop and I am starting to work in some lights.

Pep

[ghurd]

Have you cnsidered using the start windings seperately?

Garbogen style.

G-

[Peppyy]

I did think about running 4 wires down the tower and possibly using the start winding for charging a different set of batteries. I almost pulled them out today to see just what I could get out of them with a load hooked up.

The problem I have is that while I may be charging 15 to 19 volts on the main it would still be below 12 volts on the start winding, or at least there was about a 50% difference when I was no-load testing. I thought if nothing else, perhaps I would light a few led's with that winding so I could see at a glance how it was turning at night.

I made a 1/2 bridge with a current limiting resistor and you should see how that strobes an led. I might be able to use this in combination with a optical counter to track rpm. Not very practical but kind of fun.

At the moment I am looking for a bigger motor to do some better load testing with the current configuration. I am using a single phase full wave rectifier, 25A I think, mounted on a large heat sink with a touch of thermal grease and I can't even begin to warm it up. I bought 3 so I could run them in parellel if need be.

[ghurd]

You may be able to seperate the starts into 2 halves then series them?

Most of my starts are a huge number of turns of smaller wire, meaning they should cut in faster.  It's not like I do anything normal, so I could be wrong.

But I can help you out with the LED idea if you want. Cheap and easy. No problem.

G-