| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp glowing device for lighting a discharge lamp while preventing the lowering of lamp voltage at the time of low temperature. SOLUTION: As a discharge lamp L, FL40S/36 is used. A series circuit of a temperature sensitive resistor R0 having a characteristic that resistance thereof is lowered in response to the temperature lowering and a voltage dividing resistor R1 is connected between both ends of a smoothing capacitor C1 . Switching elements Q1 , Q2 are turned on/off each other by the control signal from a drive circuit IC. A comparator CP for comparing the both ends voltage of the resistor R1 with the reference voltage Vref is provided, and the output signal of the comparator CP is input to the drive circuit IC. The both ends voltage of the resistor R0 and the reference voltage Vref are set so as to be equal to each other at -5 deg.C of the peripheral temperature. When the signal from the comparator CP becomes a high level, the drive circuit IC controls the switching elements Q1 , Q2 so that the oscillation frequency of an inverter circuit comes to close to the resonance frequency. |
