| 摘要 |
PURPOSE:To realize a connection between a polarity change-over switch and a motor with two lines regardless of the type of a DC motor, by forming a limit switch part by combining the circuits containing a diode and a limit switch connected in series. CONSTITUTION:In the state of initialization under which the antenna ANT is through with its contraction, the limit switch part Z is shown by the diagram. When the change-over switches S1 and S2 are switched to the (a) side, the DC flows to a closed loop of the power source E motor M diode D1 limit switch LS1 switch S2 power source E. Accordingly, the motor M has a forward rotation to expand the antenna ANT. When the ANt reaches its limit of expansion, the switch LS1 opens the contact with the LS2 closing the contact. And no current flows to the motor M since the diode D2 has an adverse polarity. Then the switches S2 and S2 close at the (b) side, and thus the motor M has an adverse rotation to contract the ANT. When the ANT reaches its limit of contraction, the LS1 closes the contact with the LS2 opening the contact. Thus the motor M stops its rotation. |
