Quieter from the ferrite doesn't make any sense to me, unless its from the extra weight, or a different physical charicteristic of the assembly.
I'm convinced it's because the ferrite is a 16 pole where the neo is a 12. The generator in the neo unit makes groaning noises at various speeds and at one certain speed makes a howling noise that reminds me of some experimental stators I wound once. If you put blindfolds on and somebody led you to the base of the tower with the 16 pole ferrite on it, you'd swear there's a 31-20 Jake on that tower. That's exactly how it sounds. It's got a nice hum to it that gets slightly louder with more power output. But none of the groaning and howling that the neo generator makes at certain speeds.
Smoother doesn't make any sense to me either. Higher frequency should be a far smoother output, and not worse enough to make an analog meter pulse if the lower frequency machine is smooth.
I believe that's something in the Classic controller that does that. The DC output pulses at low outputs from 5-10 amps. At least with the neo one it does. With the ferrite machine it does not do that. I attributed that to the fact that the ferrite machine has such smooth DC input to the controller, where the neo is probably a little "bumpier". I don't know for sure.
2 things I really like about this post.
1) Same power output, with the same dia, from very different machines.
They're actually the same machine with different generators. VERY different generators. I designed the neo one to run at higher voltage, as my thoughts were to use the clipper for heating water with the higher voltage turbine. That didn't really pan out because it requires the machine to operate at maximum rpm all the time. I found out that it's better to use the solar Classic controller with what they call "Waste Not Hi" mode in the controller to heat the water. And I also found out that the multiple Classic controllers play VERY nicely with one another.
I did design the different generators to have very similar power curves, although on paper the neo one should've been a little more powerful. And it may be - but I think the reason they are both so close is that I'm running my blades right up against the edge of their performance envelope with either generator. To get the extra capacity from that neo generator that I know it has in it, I'd have to put bigger blades on the turbines. At 21-22 amps and 125 volts, the stator windings barely get warmed up in it. It's wound with 13 AWG and it could easily handle 30 amps. But 30 amps @ 125 volts is 3.7 kW. And it could easily handle running at 150-180 volts. But 30 amps @ 180 volts is 5.4 kW. It takes 35-40 mph wind to get that from my 3.2 meter blades.
The neo generator is incredibly powerful. Watch this video, which is a demonstration of throwing the shorting switch and engaging the clipper load at Full Dawg. To bring a 45 lb 10 foot rotor to a dead stop like that, that fast, takes some VERY powerful braking:
2) The power difference between 25MPH /1.7KW and 28MPH /2.5KW (12% increase in wind for a 47% increase in output).
You bet. As the wind picks up, that's where your power is. I've had the ferrite machine pushing over 4 kW @ 100 volts when I first built it and was experimenting with it to see what it would do. But it takes 35 mph wind to get it.
The thing is, the Classic controller is good for 94 amps on a 24 volt system, which is 2.8 kW @ 30 VDC. BUT - the Classic will de-rate itself as it gets hot from continuous high output. So if the controller gets hot it might de-rate itself down to only 84 amps. So I have amp output limit set in the controller at 84. When the DC amps to the battery gets to 84 and the wind picks up more, the controller starts to unload the turbine and let the input voltage climb. When it climbs to where I have the clipper set to kick in, the clipper takes over and brakes the turbine by applying ever increasing load if it tries to speed up more.
So my end arrangement on these turbines, that I settled on, was to limit the power to the battery to 2.5 kW and use the clipper for a brake to keep the turbine out of over-speed. And forget about using the clipper to heat water. It takes too complicated of a system, too much wire, and too many elements to heat water with three phase power. The system I have set up now where the factory stock thermostats in the water heaters switch elements as the water heats up works good. And I'm only running one 2 kW heating element at a time during the process.
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Chris