A vacuum tube diode is constructed with a glass envelope sort of like a light bulb, and it has a filament like a light bulb which heats up the cathode which in turns emits electrons. It also has a metal conductor inside called a plate, and when the cathode is more negative than the plate, electrons flow from the cathode through the vacuum to the plate where they then continue on through the rest of the circuit. If, however, the plate is more negative than the cathode, then the electrons are repelled by the plate and stay near the cathode and no current flows, generally speaking. | A vacuum tube diode is constructed with a glass envelope sort of like a light bulb, and it has a filament like a light bulb which heats up the cathode which in turns emits electrons. It also has a metal conductor inside called a plate, and when the cathode is more negative than the plate, electrons flow from the cathode through the vacuum to the plate where they then continue on through the rest of the circuit. If, however, the plate is more negative than the cathode, then the electrons are repelled by the plate and stay near the cathode and no current flows, generally speaking. |