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Evolution of Electronics

I'm wondering if anyone else had heard this story. When Edison finally developed a practical light bulb he observed that there would always be a deposit forming on the glass. That is when he added an additional element to the bulb to try and alleviate the problem. That's when he discovered the 'Edison effect'.
 
Edison was trying to understand the observed phenomenon of vapor deposition but discovered thermionic emission.

http://www.ieeeghn.org/wiki/index.php/Edison_Effect

The name Edison Effect was given to a phenomenon Edison observed in 1875, although it'd been reported two years earlier in England. Edison refined the idea in 1883, while he was trying to improve his new incandescent lamp. The effect is this: in a vacuum, electrons flow from a heated element -- like an incandescent lamp filament -- to a cooler metal plate.

Edison saw no special value in the effect, but he applied for a patent anyway. Edison patented anything that might ever be of value. Today we call the effect by the more descriptive term 'thermionic emission'. In any case, the magic of the effect is that electrons can flow only from the hot element to the cool plate, but not the other way.

The Fleming Oscillation Valve was the first practical application of the Edison Effect used as a vacuum tube rectifier and detector. It was invented by J.A. Fleming in 1904 and was the major influence on the development of wireless telegraphy and telephony. The Fleming Valve is considered by most wireless historians to be the grandfather of the modern Triode vacuum tube.
 
That's more precise than my story. I see alot of sources gloss over those details, I'm in the midst of rediscovering what a marvelous technology they are.
 
Pick up a book on physical electronics from the 50's or 60's and you'll learn about all kinds of interesting details. The one I have is "Physical Electronics" by Hemenway, Henry, and Caulton, Wiley, 1962.
 
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