| 摘要 |
PURPOSE:To make it possible to mechanically judge the flickering of a neon lamp, by holding the wave form of the light changing timewise emitted from a neon lamp in a same phase wave form and an inverse phase wave form and comparing the previous level with the present level by using respective two hold circuits. CONSTITUTION:The light of a neon lamp 2 is detected by a light detector 1 and amplifier by an amplifier 3 to be held to hold circuits 4-7. Because the amplifier 3 alternately outputs a same phase wave form and an inverse phase wave form, said light is held to the hold circuits 4, 5 in the same phase wave form and held to the hold circuits 6, 7 in the inverse phase wave form. The difference between the held signal and a present signal is taken by a subtractor 8 and the absolute value of the output from said subtractor 8 is calculated by an absolute value circuit 9 to be given to a comparator 11. The comparator 11 compares the output of the circuit 9 with the flickering level preset to a setting device 10 and, in the case of inferiority, an inferiority judge signal is held to an inferiority judge and hold circuit 12. Because the circuit 12 receives no signal other than the signal in an external signal 13 (measuring period), the output of the circuit 12 is turned OFF when the external signal is turned OFF after the elapse of the measuring period. By this method, the flickering of the neon lamp 2 can be judged. |
