| 摘要 |
PURPOSE:To enable indication of revolution speed difference between rotary members in a mobile argricultural machine or the like, with a simple construction by moving the pointer in response to a difference in currents supplied to multiple coils of a meter. CONSTITUTION:When the rotary shafts 1 and 2 rotate at a same revolution speed, the drive currents 1a and 1b are equal so that the rotation force of permanent magnets due to the coils 14 and 15 are cancelled to allow a pointer 18 to point to zero. When there occurs a difference in revolution speed between the rotary shafts 1 and 2, the current 1a differs from the current 1b so that the magnet 16 is turned in a predetermined direction to move the pointer 18 by an angle theta. Thus, by forming the dial 19 to correspond to the revolution speed difference, the pointer 18 is able to indicate which of the shafts 1 and 2 has a greater revolution speed and the speed difference between the two shafts. |
