| 摘要 |
PURPOSE:To obtain accurate information on the remaining time to reach specific tube wall temperature by making a display while making the blinking of a fluorescent lamp fast stepwise until the specific tube wall temperature is reached and turning on the fluorescent lamp continuously after the specific temperature is reached. CONSTITUTION:Temperatures T1 and T2 which are lower than the preset tube wall temperature T0 in order are set, and corresponding output voltages of a thermistor 2 are denoted as V1 and V2 and inputted to uninverted input terminals of comparators 3, 4, and 5. When the tube wall temperature of the fluorescent lamp 1 is lower than T1, a driving transistor TR16 is controlled with the output of an OR circuit 15 and a display element 17 blinks at its frequency f1. Then when the tube wall temperature of the lamp 1 is between T1 and T2, the element 17 blinks according to a pulse signal of frequency f2 from an oscillator 7. Then when the tube wall temperature of the lamp 1 exceeds T2 and lower than T0, the element 17 blinks at a frequency f3 (f1<f2<f3) from the oscillator. Further, when the tube wall temperature of the lamp 1 rises above T0, the output of a comparator 5 is inverted by a NOT circuit 14 and the driving TR16 is turned on through an OR circuit 15 to turn on the element 17 continuously. |
