| 摘要 |
<p>PROBLEM TO BE SOLVED: To miniaturize a filament by dropping the voltage, and enhance the conversion efficiency to parallel rays. SOLUTION: A commercial power supply signal lamp 1 is provided with a power supply control device 4 which performs a conversion into pulsating current PW provided with appropriate effective voltage lower than that of a commercial power supply AC by executing phase control for the commercial power supply by means of a three terminal thyristor 4a, its filament can be made smaller in size with voltage dropped much more by making a light source 2 the commercial power supply signal lamp 1 where its filament 2a satisfies a specification corresponding to the effective voltage of pulsating current PW, and a conversion efficiency to parallel rays can be also enhanced by making a light emitting area to be located at the focus of a reflection mirror smaller.</p> |
