| 摘要 |
<p>PURPOSE:To prevent overrun of a travelling object at the position of more than one rotation by stopping it through the counting detection signals of detection elements so arranged thereon to be sensitive to permanent magnets buried along a loop track. CONSTITUTION:Permanent magnets 3 and 4 are buried along a loop track 1 and detection elements 5 and 6 are so arranged on a travelling object 1 as to be sensitive to the permanent magnets 3 and 4. When a rotary direction command switch 13 is operated to the normal position, a command signal 31 moves to ''H''. The travelling object 2 rotates normally passing the permanent magnet 3 and returns to the permanent magnet 3 after one rotation. Each time the detection element 5 detects the permanent magnet 3, the detection signal 32 is output. When counting the detection signal 32 upto two, a counting circuit 18 opens a switch 14 to stop the travelling object 2. To reverse the rotation, detection signals 36 of the detection element 6 are counted with a counting circuit 21.</p> |
