Keywords: Triode demonstration circuit.svg triode vacuum tube works The filament heated by a separate current provided by a low voltage source V<sub>f</sub> typically 3-6V heats the cathode above it The cathode releases electrons into the tube The plate is biased with a positive voltage from 22 to several hundred volts The electrons are attracted to the positive plate and flow to it through the grid establishing a DC plate current The input voltage v<sub>i</sub> applied to the grid controls the plate current; an increase increases the number of electrons allowed through the grid The grid bias source V <sub>g</sub> applies a negative voltage of a few volts to the grid to ensure that it doesn't become positive on the positive input voltage swings causing grid current 2013-06-25 16 52 12 own Chetvorno cc-zero Uploaded with UploadWizard Vacuum triode circuits |