Monday, September 5, 2011

A failed upgrade to the three phase generator

After I created a three phase generator, my first thoughts were about how could I upgrade it to increase the power. Ideally I wanted a generator which could produce three phase power at a low enough frequency that I could see the A B C phase rotation in real time on LEDs.

The most obvious way I could upgrade my generator was with a iron core. The iron in the core gets magnetized whenever a magnet passes by. This dramatically increases the magnetic flux through the core and therefore increases the voltage produced by the generator. The best material for such a core is laminated steel. This is complicated and expensive if you don't have the tooling. So I followed another DIY generator page and used iron filings for a core.

The first thing I tried was to go into my side yard with a magnet. This failed. The soil was too hard for me to get any significant number of filings from it.

Next, I tried to destroy an old rusty pan with a file. This worked, but was way too much work. I then tried drilling a whole bunch of holes in the pan with a drill. This also worked, but also was too much work. There just isn't as much steel in a muffin pan as you would expect.

Next, I tied two large neodymium magnets to a string and went for a walk dragging the magnet around. Eventually, I found a big area with loose dirt next to a road. This was just full of iron filings and in ten or fifteen minutes I was ab to get what I needed.

After getting home, I cleaned the filings by dumping them on the ground and picking them back up until I got the dirt out of them.

Then I mixed the filings with wood glue and filled my cores with the sticky mess.

I then put the rotor on the generator and tried to spin it. Nothing. Not that it didn't produce any Voltage, but it didn't spin. The magnets were so strong that they bent the cd pulling all the magnets right up to the core. The rotor was just not strong enough to spin them.

I thought I could fix this with a stronger rotor. So I went and bought a 4.5 inch saw blade and mounted the magnets on it. This failed too. Instead of the top CD bending, the bottom CD bent.

I tried gluing the bottom cd to the acrylic plate. Still, no luck. The magnets could rotate if I got them high enough, but not fast enough to produce a reasonable voltage.

The last thing I did was put 8 smaller magnets on it. I couldn't rotate unless the magnets were well above the cores, but finally I got a volt out of the generator. I was still not all that happy with the output though. So I went ahead with a redesign of the generator.

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