The heater element is usually made of tungsten wire and is used for heating the coated sleeve to a temperature ... CIRCUIT SCHEMATIC Electron tubes, like all other electronic components, are usually represented by a symbol in what isanbsp;...
|Title||:||Elements of electronics|
|Author||:||Henry V. Hickey, William M. Villines|
|Publisher||:||Gregg Division McGraw-Hill - 1980|