| 摘要 |
PURPOSE:To reduce the restriking voltage and improve the lamp efficiency by increasing the luminous tube diameter within a specific range. CONSTITUTION:In a high-pressure sodium lamp having a built-in ballast and provided with a luminous tube 2 made of a translucent ceramic tube and a resistor 3 made of a tungsten filament connected in series with the luminous tube 2 in an outer tube 1 kept at high vacuum, high efficiency and stable lighting throughout the life time can be obtained by simultaneously satisfying two equations 0.0057Wl+4.53<=D<=0.0067Wl+6.27, 0.02Wl+100<=Vb, where D is the luminous tube diameter, Vb is the luminous tube voltage, and Wl is the lamp voltage. |
