| 摘要 |
PURPOSE:To improve the reliability on starting by providing a metal rod of a bimetal switch in a start circuit of high voltage metal steam discharge lamp such as metal halide lamp such that the cross-sectional area of the metal rod meets specific requirements. CONSTITUTION:A start circuit in which a bimetal switch 4, heater element 5 and resistance 6 are interconnected in series is connected in parallel with a high voltage metal steam discharge lamp 3 such as metal halide lamp to be connected through an inductive ballast stabilizer 2 to a 200V commercial power supply 1. Elements in the circuit are set so as to meet rquirements, V2/R0>=0.4, S>=(5V2/R0+3)X10<-3>, assuming that the sectional area of contact rods 8, 8' of the bimetal switch 4 is Scm<2>, voltage at the luminous tube side of the stabilizer V2 and resistance value of start circuit at the normal temperature R0OMEGA. Thus, the optimum pulse height and necessary duration t>=0.1sec of pulses for lighting the discharge lamp are obtained from the chattering phenomenon when the bimetal switch is closed to improve the reliability on starting. |
