In a vacuum tube, are the anode and the cathode connected in any way?
In the wikipedia article, they refer to the cathode as a filament, which I thought was a bit odd. The only other filament I'm familiar with is in a light bulb. I was reading a book about vacuum tubes earlier, when I looked them up in wikipedia searching for a diagram: vacuum tube. Basically, a vacuum tube is a capacitor with a vacuum as the dielectric? Does a vacuum tube retain a charge? They seem to have the same principle: anode, cathode, dielectric. In a way, a battery seems to also be similar; the difference being the galvanic process involved. I attached a picture of a Daniel's cell from back in the day.