4 ms·

Thank you for your excellent comments. I never understood what made vacuum tubes good transistors. How does the gate voltage control the commercial loan conduct

• blattimwind 8y ago
  > I never understood what made vacuum tubes good transistors. They generally aren't. Vacuum as-in the medium may be technically superior, but vacuum tubes as practically implemented weren't just displaced because solid state was easier to manufacture, but also because solid state quickly outperformed valves in many areas. (There are areas where valves held out for much longer and are still used today in some cases, e.g. transmitter output stages). That being said a great thing about valves is that they're very hard to kill. They can take huge momentary overloads (a bit like magnetics, but with much shorter time constants), which would literally detonate similarly specced solid state output stages. And because they can run much hotter than any known solid state tech they can have huge energy densities and can be cooled very efficiently (boiling water cooling): https://upload.wikimedia.org/wikipedia/commons/8/80/Rs2041_siedegekuehlt.jpg https://upload.wikimedia.org/wikipedia/commons/8/80/Rs2041_s... (Siemens RS2041V, 600 kW output tube, diameter of the copper anode dissipating about 240 kW is 239 mm, was still made in 1999)