preheat fluorescent lamp

preheat fluorescent lamp

[′prē‚hēt flu̇¦res·ənt ′lamp]
(electronics)
A fluorescent lamp in which a manual switch or thermal starter is used to preheat the cathode for a few seconds before high voltage is applied to strike the mercury arc.

preheat fluorescent lamp, switch-start fluorescent lamp

A fluorescent lamp in which the electrodes must be preheated in order to start the arc; the preheating is initiated by either a manual switch or an automatic-starting switch.