Lee de Forest (August 26, 1873 – June 30, 1961) was an American inventor, electrical engineer and an early pioneer in electronics of fundamental importance. He invented the first practical electronic amplifier,the three-element "Audion" triode vacuum tube in 1908. This helped start the Electronic Age, and enabled the development of the electronic oscillator. These made radio broadcasting and long distance telephone lines possible, and led to the development of talking motion pictures, among countless other applications.
He had over 300 patents worldwide, but also a tumultuous career – he boasted that he made, then lost, four fortunes. He was also involved in several major patent lawsuits, spent a substantial part of his income on legal bills, and was even tried (and acquitted) for mail fraud.
