| 摘要 |
PURPOSE:To enable detecting simply a burnout of armature winding by deciding through a burnout detecting circuit whether there is an induced voltage to be induced in a detection conductor arranged between brush arms. CONSTITUTION:A pair of loop antennas 5a, 5b are firmly provided at the position between brush arms 4b and 4c, 4d and in opposition to an armature winding 3. The output of said antennas 5a, 5b is supplied to a burnout detecting circuit 9 via voltage detectors 6a, 6b, full-wave rectification circuits 7a, 7b, and comparators 8a, 8b. Said burnout detecting circuit 9 performs a given logical operation on the basis of a comparison output of said comparators 8a, 8b to detect a burnout of armature winding 3 and to output an alarm signal to an alarm circuit 10. |
