| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to smoothly rotate a monitoring camera regardless of any increase in the amount of load by reducing the number of revolutions of a stepping motor if the load torque exerted on the stepping motor exceeds the output torque of the stepping motor. SOLUTION: The drive of a stepping motor 40 drives a bevel gear 42 via a rotary shaft 41, and a bevel gear 44 engaged with the bevel gear 42. It thereby rotates a rotary shaft 43, and a monitoring camera 1 mounted on a camera mounting section 45 on the rotary shaft 43. When the stepping motor 40 is initially set to 'an output torque T1 at a drive speed N1', and if the load torque exerted on the stepping motor 40 is T2, then, it is larger than the output torque T1 of the stepping motor; therefore, the stepping motor 40 is incapable of being accelerated and brought out of step. In this case a signal compare section 48 outputs a speed change signal to reduce speed to a value lower than the drive speed N2 to a drive signal generate section 49. |
