| 摘要 |
PURPOSE:To detect sparks from the magnitude and number of the sparks by insulating and providing brushes which slidably contact the same commutator in addition to a current brush of a DC rotary electric machine, producing a voltage between the both brushes, and extracting the high frequency part of an AC except a DC. CONSTITUTION:A brush 7 is insulated from brush group 4, and mounted at the outlet side of the same commutator 1 as a commutator 1, on which one 4 of the brush group of a DC rotary electric machine is slidably contacted (at the side that the brush is isolated from the commutator). One of the brush group 4 and the brush 7 are connected to a capacitor 13 through a switch 12 by providing separately spark detecting leads 11. The DC component is interrupted by the capacitor 13, and high frequency due to spark arc is extracted through a HPF14. This output is analyzed by positive and negative side analyzers 15, 16 to obtain the magnitude and number of the pulse, which are integrated to produce an analog amount proportional to the spark amount and to indicate it on an indicator 17. In this manner, the spark can be accurately detected safely without escaping any fine spark. |
