| 摘要 |
PURPOSE:To detect abnormality with lamp alone and both of the lamp and a silicon control rectifier element by applying the outputs of the connection point of the lamp and the silicon control rectifier element to the input of a differential amplifier, and comparing and monitoring the same with the reference voltage. CONSTITUTION:If the output of an AC power source 5 and the output of the 1st DC power source 8 are applied to the circuit of a lamp 6 and a silicon control rectifier element 7, the voltage at the point A2 shifts by the 1 volt of the voltage E of the power surce 8. On the other hand, a differential amplifier 11 is applied with the divided voltage from a voltage dividing circuit 10 to its positive input (+) and the reference voltage from the power source 9 to its negative input (-), and compares both. Then, a decision circuit 18 is receiving a sampling signal C properly from a sampling generating circuit 17 and therefore the output of a terminal SV at the time when it is received is read and the presence or absence of any abnormality of the lamp and the element 7 is decided by the standard shown in the table. |
