Control grid Control grid The control grid is an electrode used in amplifying thermionic valves (vacuum tubes) such as the triode, tetrode and pentode, used to control the flow of electrons from the cathode to the anode (plate) electrode. The control grid usually consists of a cylindrical screen or helix of fine wire surrounding the cathode, and is surrounded in turn by the anode. The control grid was invented by Lee De Forest, who in 1906 added a grid to the Fleming valve (thermionic diode) to create the first amplifying vacuum tube, the Audion (triode). In a valve, the hot cathode emits
Howard Johnson (electrical engineer) Howard Johnson (electrical engineer) Howard Johnson is an electrical engineer, known for his consulting work and commonly referenced books on the topic of signal integrity, especially for high speed electronic circuit design. He served as the chief technical editor for Fast Ethernet and Gigabit Ethernet standardisation, and was recognized by the IEEE as an "Outstanding Contributor" to the IEEE P802.3z Gigabit Task Force. Johnson earned his Bachelor of Science in Electrical Engineering (1978), Masters of Electrical Engineering (1979), and PhD (1982) from Rice University. His dissertation was titled "The design of DFT algorithms". Johnson has significantly raised awareness of analog