Henry hess invented the echosounding devices because i learned it onmy project that I am doing in science which by the wasy is very very difficult.
The Chinese invented Gunpowder
relay and vacuum tube are the electronics devices which are invented firstly in the field of electronics. but they are not revolutionary as transistor which was discovered by John Bardeen.after that other devices are invented like fet mosfet and after that digital devices was invented with the help of these devices.
ben fraklin
jason woodson
Vacuum tube was invented by lee de forest .
AMD (Advanced Micro Devices)
They were invented as lightweight beach toys (and floatation devices) that could be used in the water.
I think that Henry Hess invented echo-sounding devices for mapping the ocean floor. But I am not 100% sure that is the correct answer. LOL <3
Various devices in which light is the operating principle, are by definition, the devices with the fastest operations.
The iPhone for one
Tony Jennings did he was the first person
Otis F. Boykin invented the electrical resistorand patented it on Feb. 21, 1961. He invented a total of 28 electronic devices