1. Plate – The Plate is a thin piece of metal that sits inside of the tube and is used to support the other components of the tube. The plate is also responsible for conduction of electricity from the cathode to the anode.
2. Cathode – The Cathode is the negative terminal of the tube. It is typically made out of a thin metal plate coated with an electron-emitting material, such as a tungsten or carbon filament. The Cathode releases electrons when electricity is applied.
3. Control Grid – The Control Grid is a thin metal plate located between the Cathode and the Anode. It is responsible for controlling the flow of electrons from the Cathode to the Anode. The larger the electrical charge, the more current that flows through the tube.
4. Anode – The Anode is the positive terminal of the tube. It is typically made of a heated metal plate that causes the electrons to be attracted to it when voltage is applied.
5. Heater – The Heater is the power source of the tube. It is a thin wire filament that is heated up (usually by way of an AC current) to provide a steady source of voltage to the tube.
6. Envelope – The Envelope is the envelope that houses all of the other components of the tube. It is typically made of a glass tube, but can vary in size and shape. The Envelope helps to protect the other components from being exposed to the outside environment.