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stator question
artv:
Hello again ....Flux, BobG, Ghurd, Let me first say "I think you guys are the best" ........(hope I'm not leaving anybody out) I'm sure I did... sorry.. on the 10' 12mag 9coil.... do the coils see one pole on one side, opposite pole on other side because coils are wound in circular design ...left goes up ...right goes down.........left see's north ...right see's south.......when I say sides I mean legs...is this correct? if this is true is'nt this really direct current but alternated buy orientation of mags on rotors
Flux:
I don't really follow the question.
Magnets are placed such that one disc has a N pole opposite the S pole of the other. Flux crosses the gap from N to S and returns from N to S on the next pair of poles.
Each coil of a phase has the same flux linkage at any instant. If one coil sees a flux passing from left to right, the other two coils will see the same so the three voltages add in series with coils joined start to finish.
There is no dc, there can't be. The instantaneous emf is proportional to the rate of change of flux linkage, if there is no change there is no emf. If the rotor is stationary there is no flux change and you get nothing. When it is rotating the instantaneous emf rises and falls and changes sign every time the other magnet polarity links the coils. The resultant waveform is some form of ac and the amplitude changes with rotational speed.
I think you are still thinking in terms of that original equation when you start worrying about coil legs and magnet position.
Think of it another way. When the magnets are over the centre of the coil maximum flux is linking but it is not changing so the instantaneous volts will be zero. When the opposite polarity magnet is in this position it ia again zero volts but you will be approaching from the opposite polarity.
The point of maximum flux change is when the magnets are mid way between the maximum linkage points, the rate of change is then the maximum so the instantaneous emf peaks. This happens when the magnets are over the coils legs in a conventional arrangement. Far better to think of it this way then your way of wires cutting flux lines at right angles.
You can't get dc as you can't maintain the situation, it is an interim stage in the flux linking process and the emf has to reverse when the next pole comes up.
Flux
artv:
Flux....let me first thank-you for the reply...I've been reading every thing I can find ....I've read your answer a 100 times .....when rotor links flux while entering coil leg ....starts at zero and quickly rises then hits the hole drops to zero then rises again on the other leg. all on one coil? This is AC because ....left side of coil is going up ......while right side is going down??To me thier just following the flow.So with the left hand rule the magnetic field is changing 180 degrees /coil leg..........thats to say the first180 degrees is positive(one leg)next 180 degrees negative second leg.Or is it whole coil is pushing current one direction ... then reversing with reversing polaritys on rotors.............just trying to understand
dsmith1427:
The following website does a good job of explaining three phase basics:
http://www.windstuffnow.com/main/3_phase_basics.htm
you may want to check this out. If I find any other illustrations that might help, I will post them.
artv:
...Flux....when there is motion....the emf rises and falls in conjunction with magnetic polarity.....if the magnetic polarity doesn't change.......won't the emf just rise to infinity
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