| 摘要 |
PURPOSE:To improve the reliability on an advance alarm circuit by connecting a resistor having a large resistance value as compared with the 1st and 2nd solid resistors between a contact point of the 1st solid resistor with the solid contact section of a potentiometer and an input terminal of a comparison means. CONSTITUTION:With an end connected to a contact point of a sliding contact section of a potentiometer VR connected to an input terminal of a comparison means CO1 with a solid resistance section of the 1st solid resistor R1 and the potentiometer VR and with the other end connected to an input terminal of the comparison means CO1, this device is equipped with a resistor having a sufficiently large resistance value as compared with the 1st and 2nd solid resistors R1 and R2. When a contact defect arises in the potentiometer VR, a predetermined fixed level to set an advance alarm is given through a resistor R8 to the comparison means CO1 to operate an advance alarm circuit 20A. Thus, should a contact defect arise in the potentiometer VR, then the advance alarm circuit 20A would surely be able to be operated. |
