Coil dimension confusion

[GreenTeam]

In a axial flux coil , any cool and magnet combo you know very well. I have some questions about coils , number of turns ,inductor awg  And power produced.

In a given coil size , let's say with 0.27 mm or 30 awg wire size this bobbin get us 220 turns per coil,  and with the same bobbin let's say with 0.4 mm sure I may get 150 turns. Is the power produced wildy different for both coils? And what would change if I made a coil with three wires of 30 awg twisted Into one wire and made the same size coil as the previous 2?

[electrondady1]

i cant give any values but  if the conductor in the second coil is almost 30% wider dia. than the first ,it will produce fewer volts but more amperage.
 if you want to make a 3 conductor coil do not twist the wire . you can lay  all 3 down in parallel in your coil jig.  when it comes to soldering finished coils together in the stater you can twist the starts and tails together  to simplify soldering.

[kitestrings]

Right, so the voltage will be dependent on the magnets and how many turns you have.  It will be proportional (volts/turn).  More turns, as in your example will give you a higher voltage for the same rotational speed.

If you increase the conductor size or count you will be able to carry higher amperage.  As stated, I don't think you want to twist them though.

[Adriaan Kragten]

For a certain magnet configuration, the power generated in a coil is proportional to the rotational speed and to the copper volume. But the voltage is proportional to the number of turns per coils. Assume you compare a coil with 400 turns and a 0.5 mm wire with a coil with 100 turns and a 1 mm wire. This gives the same amount of copper (if both coils have the same size). However, the voltage for the coil with 400 turns will be a factor four higher and the current will be a factor four lower for a certain rotational speed. It is easy to prove that the copper losses in the winding are the same for both coils.

Outside the generator winding, the situation is different. For a low voltage and a high current you need much thicker cables for the same copper losses in the cables.

[GreenTeam]

I wound small coils, 8 of them, and potted them into epoxy as quickly as I could.
Because as I was winding them, I did not use any glue or tape string etc to secure them!
And now, when I look at my teensy stator disc, I cant tell which way I had wound them!
I read somewhere once that I can use a magnet to figure out which way I had wound them.
Can anyone explain me the technique as to how I figure this out?
I dont want to have to throw it out because I am unsure of mistakes or not.
Its only half a plastic spoon of resin and 3 grams of PLA and some 30AWG wire.
Not alot, but still. I would rather find out first if its a throw away

[electrondady1]

never tried this, but if you connect a battery or power supply to  the leads of a coil it becomes an electromagnet.  if you place a permanent magnet over the coil it will repel or attract. you can test all the coils that way .
when i build an alternator i set up one of the mag rotors on a bearing and axle on my work bench in such a way as i can rotate the mag rotor at a set speed. then i set up the cast stator  over top with a clearance similar to the finished alternator . that's when i start to wire up the coils using a multi-meter. if you have coils flipped or wired wrong it will let you know . as you add coils the output grows . if something is wrong it reduces output .

[Adriaan Kragten]

If the eight coils are meant for an 8-pole armature the winding direction must be left-right-left-right etc. If the eight coils are meant for a 16-pole generator all eight coils must have the same winding direction. This can be left or right. If a DC current is sent through the coils the coils become electromagnets and with a PM magnet you can see if the winding direction is alternating or the same. If you find no regular pattern, the winding is useless.

[GreenTeam]

never tried this, but if you connect a battery or power supply to  the leads of a coil it becomes an electromagnet.  if you place a permanent magnet over the coil it will repel or attract. you can test all the coils that way .
when i build an alternator i set up one of the mag rotors on a bearing and axle on my work bench in such a way as i can rotate the mag rotor at a set speed. then i set up the cast stator  over top with a clearance similar to the finished alternator . that's when i start to wire up the coils using a multi-meter. if you have coils flipped or wired wrong it will let you know . as you add coils the output grows . if something is wrong it reduces output .

Would the power from a multimeter continuity circuit test check be enough electricity? My MasterCrap DMM lit up a LED on continuity, thats why I ask

[electrondady1]

?  try it, let us know.  maybe a magnetic compass would be sensitive enough to show you . if one of your coils is flipped just switch the leads around that should correct the problem. it the coil leads are already  bedded in resin you  have to carefully dig into  the resin to free up enough copper to make the switch.

[Mary B]

never tried this, but if you connect a battery or power supply to  the leads of a coil it becomes an electromagnet.  if you place a permanent magnet over the coil it will repel or attract. you can test all the coils that way .
when i build an alternator i set up one of the mag rotors on a bearing and axle on my work bench in such a way as i can rotate the mag rotor at a set speed. then i set up the cast stator  over top with a clearance similar to the finished alternator . that's when i start to wire up the coils using a multi-meter. if you have coils flipped or wired wrong it will let you know . as you add coils the output grows . if something is wrong it reduces output .

Would the power from a multimeter continuity circuit test check be enough electricity? My MasterCrap DMM lit up a LED on continuity, thats why I ask

No it is very low current.

Be VERY careful doing this! Those coils are very low resistance and will get hot quickly unless you limit the current, hot enough to burn off insulation! And burn fingers! Batteries don't like short circuits either. A current limiting resister could be used, would need to know coil ohm reading so I could do the math...

[GreenTeam]

never tried this, but if you connect a battery or power supply to  the leads of a coil it becomes an electromagnet.  if you place a permanent magnet over the coil it will repel or attract. you can test all the coils that way .
when i build an alternator i set up one of the mag rotors on a bearing and axle on my work bench in such a way as i can rotate the mag rotor at a set speed. then i set up the cast stator  over top with a clearance similar to the finished alternator . that's when i start to wire up the coils using a multi-meter. if you have coils flipped or wired wrong it will let you know . as you add coils the output grows . if something is wrong it reduces output .

Thank you! Glad I have not done this yet lol


Would the power from a multimeter continuity circuit test check be enough electricity? My MasterCrap DMM lit up a LED on continuity, thats why I ask

No it is very low current.

Be VERY careful doing this! Those coils are very low resistance and will get hot quickly unless you limit the current, hot enough to burn off insulation! And burn fingers! Batteries don't like short circuits either. A current limiting resister could be used, would need to know coil ohm reading so I could do the math...