English electrical engineer and physicist John Ambrose Fleming died #OTD in 1945.
He is best known for his invention of the vacuum tube diode, which he patented in 1904. The vacuum tube diode, also known as the Fleming valve, was the first practical vacuum tube and allowed for the detection & amplification of electrical signals. It was a crucial component in early radio receivers and telecommunications systems, laying the foundation for the development of modern electronics.
