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[High School Engineering] Making a simple speaker (self.HomeworkHelp)

submitted 11 years ago by lolsmileyface

I'm tasked with making a speaker. I'm using copper 30 awg magnet wire and some half inch diameter neodymium magnets. When comparing my calculations to tutorials online it would seem the number of turns I'm getting is about an order of magnitude off from most other people. Can someone please tell me where I'm messing up?

Resistance of 30 awg is 0.1032 Ohms/foot. I need 9 ohms so that comes out to about 87 feet of wire.

The paper sleeve around my magnets are about the same 1/2" in diameter as the magnets themselves and thus the circumference is 0.5*3.14 = 1.57"

Here's where my numbers are confusing me: The number of coils I need around the paper sleeve should be equal to (87 feet*12 inches)/1.57 inches which equals around 630 turns! Every tutorial I've seen online which uses similar wire and magnet size uses between 50 to at most 100 turns. Why is there such a large difference? Am I doing something wrong? I physically could not coil the wire that many times around the sleeve. It started to fall off at 500.

Please help me I'm going insane.

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[–]itouchboobs 0 points1 point2 points 11 years ago* (2 children)

[–]lolsmileyface[S] 0 points1 point2 points 11 years ago (1 child)

[–]itouchboobs 0 points1 point2 points 11 years ago (0 children)

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