| 摘要 |
PURPOSE:To control a driving speed to the best speed even if a source voltage varies by detecting the source voltage prior to motor driving, and determining a driving duty ratio according to the voltage and stabilizing a driving speed. CONSTITUTION:A monitor voltage V'BAT from a battery voltage detecting circuit 64 is led to an input terminal I1 and A/D-converted by an A/D converter 63 and the result is inputted to a CPU 61. The CPU 61 determines the duty ratio of driving pulses by a specific duty ratio control means so that the driving speed is held stable according to the detected voltage. A driving motor 23 controls the speed of the photographic is braked, the on-off duty ratio is varied according to the voltage of a battery 75 to make the braking time different. |
