First dynamos

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Original poster: Esondrmn-at-aol-dot-com 

My wife bought me a great book for Christmas.  Empires of Light by Jill 
Jones.  Random House, New York, 2003.  The description inside says: Edison, 
Tesla, Westinghouse and the race to electrify the world.

Of course I have read most of this before in several other books but the 
chronological history is very interesting.  I had forgotten just how much 
Faraday contibuted to the science of electricity.  Certainly more than any 
other single person.  He was the first in 1831 to discover the relationship 
between magnetisim and electricity and was the first to generate 
electricity by moving a magnet through a coil of wire.  He also invented 
the first continuous current generator.  It was comprised of a hand crank, 
and a 12" copper disk that rotated between the opposite poles of a 
permanent magnet.  Commutating wires were connected to the axle and the rim 
of the disk.

Over the next several years, many inventors built bigger and more efficient 
dynamos.  By the early 1870s a Belgian engineer named Zenobe-Theophile 
Gramme, working in Paris, had developed a more powerful direct current 
generator and had also invented the electric motor, "which he showed was 
just a dynamo or generator running in reverse".  "Gramme incorporated a 
major advance introduced by Werner von Siemens: The bit of genius that 
propelled his generator ahead of all others was using electromagnets rather 
than regular magnets".

Paul Jablochkoff, a Russian engineer also working in Paris, used the Gramme 
generator to develop a new arc lighting system that was used for street 
lighting.  Because the system used D.C., one of the carbon sticks in the 
arc lights always burned up twice as fast as the other.  Gramme solved this 
problem by redesigning his generator to produce alternating current. I 
believe this was in 1876.

Just thought I would mention this since it is the first time I have heard 
anyone other than Nikola Tesla credited with inventing the A.C. dynamo.  I 
haven't got to Tesla in the book yet, Edison is still trying to perfect his 
light bulb and working on an electrical distribution system to light New 
York.  Edison did have a hell of a job ahead of him.  Few of the components 
that he needed even existed at the time.  He had to figure out how to 
splice and insulate wire (all his cables were buried at that time), disign 
switches, fuses, insulators, lighting fixtures, etc. etc.

Ed Sonderman