| 摘要 |
PURPOSE:To permit to monitor also such an anomaly as defective contact of the brush by detecting a surface temperature of the collector ring in a contactless manner. CONSTITUTION:A surface temperature of a collector ring 1 is detected by a temperature detector 4 in a contactless manner to obtain a temperature signal (a). The temperature signal (a) is turned to a temperature differentiation signal (c) through a differentiator 6, and then fed to a temperature change rate alarm generator 7. When the temperature differentiation signal (c) exceeds a positive or negative alarm level, an alarm signal (d) assumes 1 and an alarm signal (e) from an OR circuit 9 also assumes 1, so that an alarm is issued from an alarm device 10. The temperature signal (a) is also input to a temperature alarm generator 8, and when it exceeds either one of two alarm levels, an alarm level (b) assumes 1 so that an alarm is issued from the alarm device 10 similarly. By so doing, it becomes possible to monitor not only spark discharge caused in the current collecting section, but also also such an anomaly as defective contact of the brush. |
