Patent attributes
A dimming-control lighting apparatus for an incandescent electric lamp with less accompanying color temperature change, using a dimming power source installed in TV studios or theater stages, is disclosed. The voltage of the first filament whose rated voltage is lower than the maximum output voltage of a dimming power source rapidly rises to the sawtooth voltage of the dimming power source, and after the first filament reaches a constant color temperature, the output of the second filament having the same rated voltage as the maximum output voltage of the dimming power source is delayed to thereby light the second filament. Thyristors and connected to the first filament and the second filament, respectively, are operated by the control of control means based on the detection of the ignition phase angle of the sawtooth wave of the dimming power source to thereby light the first filament and the second filament (lamps), as mentioned above, so that dimming control having a smaller color temperature change is performed using the dimming power source.
