| 摘要 |
PURPOSE:To determine a failure of motor without checking such failure with a tester and the like by connecting alarm terminals of a plurality of motors in series and by detecting the change in flowing current. CONSTITUTION:If at least one of motors 3-5 is defective, a voltage proportional to the number of defective motors is generated at a measuring point 12. Said change of voltage is detected by the use of a comparator circuit 14. In this case, an alarm signal can be generated when at least one motor is defective, if values of resistors R3 and R4 are set so that a reference voltage 11 of the comparator 14 is intermediate between a voltage of the measuring point 12 in normal operation and that of said point 12 when one of motors 3-5 becomes defective. |
