History of electronic engineering on to develop the first practical and widely used radio wave based communication system. In 1904, John Ambrose Fleming, the first professor of electrical Engineering at University College London, invented the first radio tube, the diode. Then, in 1906, Robert von Lieben and Lee De Forest independently developed the amplifier tube, called the triode. Electronics is often considered to have begun with the invention of the triode. Within 10 years, the device was used in radio transmitters and receivers as well as systems for long distance telephone calls. The invention of the triode amplifier, generator, and detector made audio communication
Electrohydraulic servo valve Electrohydraulic servo valve An electrohydraulic servo valve (EHSV) is an electrically operated valve that controls how hydraulic fluid is sent to an actuator. Servo valves are often used to control powerful hydraulic cylinders with a very small electrical signal. Servo valves can provide precise control of position, velocity, pressure, and force with good post movement damping characteristics. A servo valve receives pressurized hydraulic fluid from a source, typically a hydraulic pump. It then transfers the fluid to a hydraulic cylinder at a pressure that is proportional to an electrical signal that it receives. Most hydraulic control valves are binary, they