LUMINOUS RADIATION ELECTRON TUBE LIGHTING DEVICE

PURPOSE:To prevent a red heat of the cathode of a luminous radiation electron tube, to reduce the power loss so as to improve the lamp efficiency, and to extend the lamp service life, in a luminous radiation electron tube lighting device. CONSTITUTION:Discharge currents I1 and I2 fed from DC power sources E1 and E2 flow from the anode 1 of a luminous radiation electron tube G to cathode terminals 2a and 2b respectively, a constant heating current If is fed from an AC power source I2 to a cathode 2 through a capacitor C, and the constant heating current If on the cathode 2 has been made in the reverse direction to the discharge currents I1 and I2. The current is eliminated on the cathode 2 of the luminous radiation tube G, and a red heat of the cathode 2 can be suppressed.