gar
Senior Member
- Location
- Ann Arbor, Michigan
- Occupation
- EE
190211-2234 EST
172 years ago today, 11 February 1847, Thomas A. Edison was born. 72 years ago on his 100 th birthday I sent a hand keyed Western Union message to members of his family from the Smiths Creek railway station in Greenfield Village. I am sure that this was just a formality, and that the actual message traveled by Teletype. Today the telegraph desk is rotated 90 degrees from its original position. The president of Western Union was present, Henry Ford was not because his health was failing. Henry died in April 1947 during a period when we had very heavy rains and the Fairlaine Estate dam was totaly covered in water. This was the highest level I ever saw the Rouge River. So Henry died by candlelight as he had been born. His estate was DC powered and had battery backup, but no AC to DC conversion as added backup. A dam flooded over by many feet of water does not produce much power.
My life overlapped Edison's, but I was too young to meet him. I believe some of my older schoolmates did meet Edison, but none are around now for me to ask them. Frances Yehl I did meet, but too young to ask questions I would ask today. Yehl was the last living person to have been present at the making and burning of Edison's first successful light bulb in 1879.
My photo P12 at http://beta-a2.com/EE-photos.html shows Edison, Ford, and Yehl at the 1929 reenactment. President Herbert Hoover was also present, but not in this photo. The movie of the reenactment is available from the National Archives.
In Yehl's book he mentions Edison's discovery of magnetic iron core saturation. He also discusses Edison's understanding that to make a practical electrical power distribution system that the loads needed to be connected in parallel, the voltage reasonably high, and the source impedance low. This was in contrast to common thinking at the time of maximum power transfer as the criteria, which is extremely inefficient. I think 110 was a practical compromise between what could be made and efficiency. Note that Edison invented the 3 wire distribution system to improve efficiency. Thus, the concept of a neutral goes back a very long way.
Edison's electric lighting system initially was not less costly than gas lighting, but it was more convenient and safer.
.
172 years ago today, 11 February 1847, Thomas A. Edison was born. 72 years ago on his 100 th birthday I sent a hand keyed Western Union message to members of his family from the Smiths Creek railway station in Greenfield Village. I am sure that this was just a formality, and that the actual message traveled by Teletype. Today the telegraph desk is rotated 90 degrees from its original position. The president of Western Union was present, Henry Ford was not because his health was failing. Henry died in April 1947 during a period when we had very heavy rains and the Fairlaine Estate dam was totaly covered in water. This was the highest level I ever saw the Rouge River. So Henry died by candlelight as he had been born. His estate was DC powered and had battery backup, but no AC to DC conversion as added backup. A dam flooded over by many feet of water does not produce much power.
My life overlapped Edison's, but I was too young to meet him. I believe some of my older schoolmates did meet Edison, but none are around now for me to ask them. Frances Yehl I did meet, but too young to ask questions I would ask today. Yehl was the last living person to have been present at the making and burning of Edison's first successful light bulb in 1879.
My photo P12 at http://beta-a2.com/EE-photos.html shows Edison, Ford, and Yehl at the 1929 reenactment. President Herbert Hoover was also present, but not in this photo. The movie of the reenactment is available from the National Archives.
In Yehl's book he mentions Edison's discovery of magnetic iron core saturation. He also discusses Edison's understanding that to make a practical electrical power distribution system that the loads needed to be connected in parallel, the voltage reasonably high, and the source impedance low. This was in contrast to common thinking at the time of maximum power transfer as the criteria, which is extremely inefficient. I think 110 was a practical compromise between what could be made and efficiency. Note that Edison invented the 3 wire distribution system to improve efficiency. Thus, the concept of a neutral goes back a very long way.
Edison's electric lighting system initially was not less costly than gas lighting, but it was more convenient and safer.
.