Thermionic Emission Conservation of Energy I am learning about thermionic emission and how it led to the vacuum tube. It is said that thermionic emission was a way to increase the flow of electrons from a signal (e.g. in a radio receiving a weak signal, boosted by thermionic emission). What I don't understand is how it &quot;generates&quot; electricity; even if the coil is heated to it's work threshold, wouldn't a coil only be able to emit as many electrons as are supplied?
Thank you for your time
I was mistaken on the principle that governs vacuum tubes. It is not that the signal is being amplified by thermionic emission; rather, the radio wave is being used as a gate to allow or block electrons from being received. Thermions are being emitted from a coil using electricity, emitting at a higher current, modulated by the radio wave as a control grid (preventing or allowing the thermions from being collected at the anode).