| 摘要 |
<p>PURPOSE:To prevent a state where loading is impossible from occurring by utilizing a switch for short-circuiting for a position detect switch, and switching surely the movable contact point of the switch whenever the loading ends. CONSTITUTION:When the connection of an operation switch SW 12 is converted from b(d) contact to a(c) contact, a current flows through a motor 11 and loading starts. At the same time, a control signal is inputted to one input of an OR circuit 15, and the signal is inputted to a muting circuit 14 and the muting is executed. The loading part moves, and when it reaches the specified position, a position-detection switch 13 switches from contact a(c) to contact b(d), cutting the current to the motor off to stop the loading. At the same time, the control signal to the circuit 14 is stopped so that the muting is released. Because the switch 13 is a short-circuiting switch, the moving contact point contacts both contacting points at switching, however, because the same current as that before the switching continues to flow, the loading also continues. That is, the loading continues until the moving contacting point of SW 13 completely departs the point of preceding connection, and when the loading ends, the contact is made with only the opposite contact point.</p> |
