| 摘要 |
PURPOSE:To perform stable operation through changing-over of small currents with a simple mechanism and circuit constitution by providing a winding drive circuit and a rewinding drive circuit and letting braking action be effected at the operation stopping by one of thses circuits. CONSTITUTION:When, for example, in high speed continuous photographing, a switch S12M is turned on by operation of the release, the transistor T2 of a motor drive circuit 7 is turned on by way of the H contact of a switch S6 and resistance R15, hence the transistor T1 goes on to let a motor 3 run. At the time when the switch S16 goes OFF upon completion of winding, the transistors T2, T1 of the motor drive circuit 7 go OFF. Since this causes the motor 3 to be operated as a generator by inertia force, a potential difference is produced between the emitter and base of the transistor T3 of a motor braking circuit 8. Then the transistor T3 goes ON to short between the terminals of the motor 3, thereby applying brake. In this way, the stable operation may be accomplished by small currents with the simple mechanism and constitution. |
