Kylmäkatodisia

Kylmäkatodisia refers to a type of gas-discharge lamp that operates without the need for significant preheating of the electrodes. Unlike hot-cathode lamps, which rely on heating a filament to emit electrons, cold-cathode lamps achieve ionization of the gas within the tube at room temperature or slightly above. This ionization process is initiated by a high voltage applied across the electrodes, which accelerates free electrons in the gas. These accelerated electrons then collide with gas atoms, creating more free electrons and ions, leading to a chain reaction known as a Townsend discharge. As the discharge intensifies, the gas becomes conductive, and a steady current flows between the electrodes.

The light produced by a cold-cathode lamp typically comes from the excitation of the gas itself or from a phosphor coating on the inside of the tube that fluoresces when struck by the ultraviolet radiation emitted by the excited gas. Common gases used include neon, argon, or mercury vapor, each producing different colors of light. Due to their inherent design, cold-cathode lamps are known for their long lifespan, robustness, and ability to operate at very low temperatures. They are often employed in applications where reliability and durability are paramount, such as in signage, backlighting for displays, and specialized scientific equipment. Their starting voltage is typically higher than that of hot-cathode lamps, but their sustained operating voltage is often lower.