A cold cathode operates at ambient temperatures and relies on strong electrical fields, secondary emission, or photoelectric effects to release electrons into a vacuum or gas-filled tube. Unlike thermionic cathodes that glow red-hot to boil off electrons, cold cathodes require higher starting voltages but consume less power overall. They are widely used in neon lamps, Nixie tubes, and older LCD backlights.
The inverter for the cold cathode backlight on this old monitor just failed.
Related terms
Cathode ray tube
A vacuum tube containing one or more electron guns and a phosphorescent screen used to display images.
Nixie tube
A Nixie tube is a vintage cold-cathode display device that glows to show numerals.
Vacuum tube
An evacuated glass or metal envelope containing electrodes used to control electron flow.