05-20-2008, 12:55 PM
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Desi Club Badshah
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Join Date: Jun 2007
Posts: 1,272
Thanks: 51
Thanked 250 Times in 65 Posts
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Re: 204 Simple Science Experiments ~ {ERG}
Electro Buzzer
(Please See Image Above)
Nail board B and wooden blocks C and D onto board A (about 5 X 5 inches). Push an iron bolt F through a hole bored in B. Wind covered copper wire G 100 times round the bolt and connects the ends to a battery and to H respectively. Bore a hole through block C and wedge the fret saw blade H firmly into it so that its end is a short distance from bolt F. Hammer a long nail K through A and bend it so that its point rests in the middle of the saw blade. Oil the point of the nail. Use a piece of beading E as a key, with a rubber band P as spring and drawing pins M and N as contacts. Join all the parts with connecting wire (remove the insulation).
If you press the key down, you connect the electric circuit, bolt F becomes magnetic and attracts H. At this moment the circuit is broken at K and the bolt loses its magnetism. H jumps back and reconnects the current. This process is repeated so quickly that the saw blade vibrates and produces a loud buzz. If you wish to do Morse signaling with two pieces of apparatus, you must use three leads as in the lower circuit diagram.
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