Richardson's handbook of projection (1930)

1036 HANDBOOK OF PROJECTION FOR connected, or it may accumulate a charge of its own account, in which event it would interfere with the flow of electrons. However, if there be a grid and it and the plate connected as shown, then it may be an advantage by adding to the effective area of the plate. At any rate, it will do no harm. NOTE. — I again warn you, do not attempt to use a tube as an amplifier which has been used as a rectifier. Bearing in mind what has been said, it may be readily understood that during the half of a wave or cycle electrons would flow freely from the hot negative filament to the negatively charged plate, but during the succeeding half wave, the plate being negative and the filament being negatively charged by the battery which heats it, none could flow, and we therefore would have only half waves flowing to the load, which of course would all flow in the same direction. It may be a bit hard for some of you to grasp the meaning of the connection shown in Fig. 389, but study it. The A. C. circuit is actually broken, except for the action in the tube itself. In other words the only current which can flow through it is the electron flow between the filament and plate. The current flow which heats the filament is D. C, of course, and does nothing but heat the filament, because it has no circuit connection elsewhere. The fact that the A. C. lead connects to it on one side affects neither it nor its action, because its other "side" does not connect. However, the A. C. has a complete circuit through the flow of electrons between filament and plate and the load back to its positive terminal. I hope I have made this clear. It is no easy task to put such matters into understandable form. I can myself