indirectly heated cathode

indirectly heated cathode

[‚in·də′rek·lē ¦hēd·əd ′kath‚ōd]
(electronics)
A cathode to which heat is supplied by an independent heater element in a thermionic tube; this cathode has the same potential on its entire surface, whereas the potential along a directly heated filament varies from one end to the other. Also known as equipotential cathode; heater-type cathode; unipotential cathode.