| 摘要 |
<p>PURPOSE:To detect surely the disconnection of a potentiometer by simple constitution by connecting a voltage dividing resistor to a plus side terminal of the potentiometer, and a resistor larger in resistance than that of the former between the plus side terminal and a movable terminal. CONSTITUTION:A resistor R1 is connected in series to the plus side terminal of a resistor R of the potentiometer 11 and a voltage of 5V is applied. A resistor R2 is connected between the plus side terminal and a movable terminal 12, the resistance values of the resistors R, R1 are set to be equal, the resistor R2 is set to be sufficiently larger than these of resistors R, R1 and the output voltage at the movable terminal 12 is set to be within the range of 0-2.5V. A CPU 14 discriminates whether the output voltage related to the slide amount of the movable terminal is within the range up to the maximum voltage of 2.5V. Any voltage excess is judged to indicate the disconnection of the potentiometer 11 and an alarm signal SG2 is issued. Hence the disconnection may be surely detected by simple construction to improve safety and reliability.</p> |
