I just watched this video on voice coils being made and it raised some questions:
It has been many used since I took any physics, but I think I remember the right-hand-rule and faraday's law. Here's my question:
If the second layer is wound in the opposite direction, then won't the induced magnetic field from the second layer be equal and opposite to the induced magnetic field from the first layer?
Wouldn't the result be 0 inductance and no net magnetic field or force?
What am I missing?
It has been many used since I took any physics, but I think I remember the right-hand-rule and faraday's law. Here's my question:
If the second layer is wound in the opposite direction, then won't the induced magnetic field from the second layer be equal and opposite to the induced magnetic field from the first layer?
Wouldn't the result be 0 inductance and no net magnetic field or force?
What am I missing?
The drill is always rotating clockwise. The first layer is applied from right to left and the second from left to right. The current will circle round both layers in the same direction, hence no cancellation.
P.S. Change over occurs at 2 minutes in.
P.S. Change over occurs at 2 minutes in.
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Cool, it still holds true, apply it to top and bottom layer and see where magnetic field points to in each.
In fact, you can extend it to 4 layer coils, like some car woofers use.
I think this video is clearer.
start winding
turn-around
end of winding
Another video. No English but a touch of Spanish will get you through. (Yes, Juan, it is Portuguese in the Brazilian style.)
start of voice-coil process, at factory speed
centragem (spider) is a waffle-iron
start winding
turn-around
end of winding
Another video. No English but a touch of Spanish will get you through. (Yes, Juan, it is Portuguese in the Brazilian style.)
start of voice-coil process, at factory speed
centragem (spider) is a waffle-iron
Let us try the tight hand rule. Form a fist with your right hand. Extend the thumb. Now as the current rotates through the windings (+ to -) represented by your fingers the magnetic direction (North) is represented by your thumb. Notice it is only the direction of the current flow going round. It doesn’t matter if it starts at the top or the bottom. Notice on a two layer coil the coil form being wound is always rotated in the same direction.
Of course if you are left handed, then your loudspeakers won’t work! 🙂
Of course if you are left handed, then your loudspeakers won’t work! 🙂
NOTICE everything, end to end, is made in-house; or worst case, still inside Brazil (magnets).
That´s the BENEFICIAL effect of high tariff.
Complex heavy machinery, large factories, lots of production, lots of "good" industrial jobs, local taxes reinvested in infrastructure (plus schools, hospitals, etc.) , none of which would exist if speaker parts or worse, fully assembled speakers o even "worser", ready made cabinets were easily available from China for peanuts.
They complain about it ("we have the most expensive I Phone in the World",etc.) but thanks that they have a strong Industry, a strong Country, always growing.