| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve an alarm function by generating an alarm, when one of the output voltages of a pair of armature coils deviates from a specific value. SOLUTION: A comparator 44A in an alarm device 4A detects the output voltage of an armature coil 12 from among a pair of armature coils, and an output voltage generates L-level comparison output, when a comparison reference voltage is equal to or less than a comparison reference voltage VR2 and genertes H-level comparison output, when the comparison reference voltage VR2 is exceeded. Therefore, when the output voltage of the armature coil 12 decreases abnormally to the comparison reference voltage VR2 or lower, the comparison output of the comparator 44A goes to L level, and an L-level voltage signal is applied to an inverted input terminal (-). Then, the comparison output of the comparator 44 turns to H level, an alarm output transistor 43 is turned on, and a display lamp 49 is driven so that it is turned on, thus alarming the abnormal decrease in the output voltage of the armature coil 12 and hence improving the reliability of an alarm function.</p> |
