| 摘要 |
PURPOSE:To reduce the overload tone of a motor by providing a terminal detection switch which detects that an operating lens barrel positions nearby a terminal of its turning range, and a control circuit which decreases the output of the motor by its detecting operation. CONSTITUTION:When switches S1 and S2 are turned on, the motor 22 starts rotating to move a pin 17 to left in a long-sized hole 18 and the position of a notch part 28 coincides with the positions of terminals 26a and 26b right before the pin 17 abuts on one end wall surface of the long-sized hole 18 to disconnet between the terminals 26a and 26b. Consequently, a current from a puls-side power source terminal 29 is applied to the motor 22 through a known current limiting circuit 31 consisting of a transistor TR1 and resistances R1 and R2, so the maximum output of the motor 2 drops, and consequently even if the switches S1 and S2 are held on continuously while the pin 17 abuts on the one terminal wall surface of the long-sized hole 18, the overload tone is reduced greatly. |
