| 摘要 |
PURPOSE:To discriminate the malfunction of a speed detecting system by providing two speed detectors, comparing and discriminating the two output signals. CONSTITUTION:The second detector B is provided in parallel with the first speed detector A in a motor 1. The speed signals (a), (b) are inputted to a voltage comparison discriminator 13. The discriminator 13 detects the differential voltage between the signals (a) and (b) to detect the malfunction of the speed system by the value. The signals (a), (b) are equal at the normal time, and the differential voltage becomes zero, but if one voltage value varies, for example, due to wire disconnection or a defect, the differential voltage does not become zero. The discriminated malfunction signal is outputted from a signal line 15, fed to a controller 3, which instructs a motor stop or generates an alarm, and fires a malfunction lamp. |
