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Littel alt lathe test.
Jerry:
Well I'm happy to say I don't have to set in the corner with the dunce cap on.
My first test was with the star stator. 116 turns of 21 gage wire. Test rpm 500. first thing I noticed. the voltage was realy low.
After a gave that a littel thought it hit me that this little alt has only 4 very small magnets and just 3 coils, a gap of about 1/8" inch between the magnets and the coils and a diameter of only 4 and 3/16".
So I jumped the rpm up to 1600. This coil group is wired star. I used a 4 ohm 400 watt none indutive resistor as load.
I plan on doing a battery load test and look at the rippel and wave form on the osciliscope but that will be in a fewdays.
I recorded dc amps and volts. Then I removed the star stator and replaced it with the jerry riged delta stator.
Here are my test results.
Jerry riged volts=4.484 Star volts=3.890
Jerry riged amps= 1.11 Star amps= .96
Jerry riged watts=4.977 Star watts= 3.734
My point is still. I you take 1 once of copper and I take 1 once of copper and we both use the same magnets same discs same everthing. You use a wire gage twice the size of mine I use a wire gage half the size of yours.
Your out of phase sires conected coils will rob you of the power that exists within the same amount of matirial and the same money spent, the same size and the same weight.
There has been some concern that this jerry riged alt will reqier more blade power.
Yes it will, I know that. But at the same time it will give you the power of an alt that was built star with larger and more expencive magnets and larger and more expencive copper and every thing else that is required for a larger alt.
This is scalable. So imagin the power you could acctuly get from a 2 KW alt if you wernt wasting its power on out of phase coils that are not phase compatible with each other.
And for those that like to speed there alt up buy puting resistance in the line so the blades can reach a more produtive rpm, you can still do that.
Personaly I don't think we should build ineficient alts with star phases just to make our blades happy.
I think we should get all the power are magnets and copper can produce and build an apropriate balde to mach that alt. Controls such as dump loads and resistance can be added down stream from the genny to make electrical addjustments on the ground.
I don't want to be standing on the ground and look up at the genny on the tower and say that genny could be making more power right now if I had used a diferant phase configuration.
If scailed up its the diferance of 124 watts. If you build a 373 watt genny it could be produceing 497 watts at the same rpm. And again I relize there will be rpm diferances with blade diameter. A higher wattage alt requiers a larger diameter blade that spins at a lower rpm.
The diferance is the alt will cut in much sooner without the nessesity to build a much lager alt.
And Dan B I'm sorry buddy but you said it yourself. The voltage is lower cause the phases are out of phase ( you are so right on that one).
As I said earlyer if your happy with your alts phases out of phase at 120 degrees you should be real happy with your speaker out of phase at 180 degrees. Thats even more noticable then 120 degrees out. But 120 out of sinc, out of wack, on a diferant page on an on is still out of phase.
At one time disc alts were built with a single disc and laminations. We got past that. Now its time for the next step.
Some one has mentioned. The comercial manufactures wouldn't make 3 phase generators if they were not eficient.
They are eficient. There 3 phase power goes to a 3 phase load. Each phase is in sinc with each phase. And as far as the car alt.
These alts are spining at thousands of rpm with coils of 12 gage wire that ony have 3 or 4 turns each.
Extreamly low DCR and extream rpm and a 200 hp motor to power them. Save the expence of a few million diodes and this alt for this aplication is quite accepable.
As far as a 3 phase generator is concerned it supplies power phase for phase. We are combining 3 difearant phases to become one dc output.
The combining prosses of star looses power through coil wired in sires that are not in phase with each other. There for the peak output of these out of phase coils can nerver be realized it lost to the 1.73 thing.
I won't design my alts that way. Magnets and copper ain't free. I want them doing all the power there capable of. Some of my tax money goes for wellfair. I refuse to but my magnets and copper on the wellfair roles.
I urge any one to do the same test of these 2 diferant phase configurations and make your own conclusions.
I've had my convictions from the start on this subject and for me they have been confirmed.
In the compairison I even gave the star configuation some help a handicap and it still lost.
If need be I can go ever my reasoning again. I would have to show more examples or try to explain why these diferances. To me its very simple and should be easy to understand.
I'm just not sure why folks are haveing trubles with very simple and obvius diferances.
Heres a couple pix of the test alt.
JK TAS Jerry
Flux:
Jerry
Any chance of comparing delta with your connection.
Flux
oztules:
Me thinks that is a bit rude don't you flux? Surely you don't wish jerry to wire the star stator up as delta?. We know that outcome......v x .58.......oohhh, you mean wire the jerryrig up as delta?. That would not be rude, that would be interesting if that is what you were alluding to.
I doesn't matter what I think or why I think it, congratulations jerry on your results. If as flux suggests you do the test with the jerry coils as delta, i think it would be interesting. I assume that the results will be the same as jerryrig.
once again well done
...........oztules
I put my round triangular hat somewhere..... hhmmm ........
Flux:
Yes I meant jerry versus delta.
It's a pity the volts are too low to see what happens into a battery.
It would also be nice to see figures for the 2 windings as star and delta into a 3 phase resistive load ( star or delta) to check that we are equal at the start.
If Jerry has a 2 volt cell it would be nice to compare the three options into a battery load.
Interesting stuff.
Flux
craig110:
Hi Jerry,
Nice numbers and keep going with your tests! Questioning "rules of thumb" is the first step to big changes.
Craig
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