Props made for: Museums- Science- Technology- Movies-TV-Books and Advertisement Projects. For Sale
 by Antiques of Science and Technology   781 245 2897

The design that should have  been.

We made our design with the basic items shown below along with an 1877 understanding of electricity and magnetism. We improved the return path for the  magnetic field and involved the diaphragm in this path. The essential items were an  electromagnet, a soft  iron diaphragm, and a fixture to hold them. This design worked. We believe that if Bell had been more familiar with the electromagnetic principals that he would have gone with this design on his first try. He got to it after the patent was in his hands.


The disk responds  to the variation of sound pressure and moves back and forth in the magnetic field of the electromagnet generating  a current and voltage in the coil representing the sound variations. We added  a fixed magnet to the end of the electromagnet core  to produce a resident magnetic field which is picked up by the disk. this makes the disk act as  armature of a generator. One could have wound the coil around a permanent magnetic as shown in the Oct 6th 1877  Scientific American. The diaphragm is used to generate the  undulating current and voltage in the coil as a transmitter. When transmitted via wires to a similar unit it would  produce sound from the vibrating soft iron disk and thus act as a receiver.

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Copyright 12/10/2004 Jim & Rhoda Morris