A cold cathode is a cathode, an electrode that emits electrons, which is not electrically heated by a filament. They are used in gas discharge lamps such as neon lamps, discharge tubes, and some types of vacuum tube. The other type of cathode is a hot cathode, which is heated by a filament which has electric current passing through it. A cold cathode does not necessarily operate at a low temperature; it is often heated to its operating temperature by other methods, such as the current passing from the cathode into the gas.
Read more about Cold Cathode: Cold-cathode Devices, Lamps, Details
Famous quotes containing the word cold:
“Shall I make it clear, boys, for all to apprehend,
Those that will not hear, boys, waiting for the end,
Knowing it is near, boys, trying to pretend,
Sitting in cold fear, boys, waiting for the end?”
—William Empson (1906–1984)