| 摘要 |
PURPOSE:To detect the abnormality of a speed detector and prevent the disordered revolution of a motor while also detecting the abnormality of the load side by comparing the detecting value of armature currents and the differential value of revolution speed signals from the speed detector. CONSTITUTION:A current detector 6 is mounted to a current circuit 5 of a DC motor 1, and the output is passed through a level transducer 10, and inputted to an addition circuit 8 as (+) value. A speed detector 2 is installed to the DC motor 1, and the output signals are differentiated by means of a differentiation circuit 7, and inputted to the addition circuit 8 as (-) value. Constant signals C' are further inputted to the addition circuit 8 as (-) value. When there is no abnormality in a speed controlling system, etc., the output of the addition circuit 8 is zero; when abnormality is generated in the speed detector 2 or abnormality is generated at the load side and current value varies, the output of the addition circuit 8 shifts from zero, and abnormality can be detected. |
