| 摘要 |
PROBLEM TO BE SOLVED: To provide an air conditioner which can wind and lower a suction grill with high torque transmission efficiency by a motor, does not require the lock protecting mechanism of the motor and only needs a small transformer for supplying power to the motor. SOLUTION: In an air conditioner for elevating and lowering a suction grill 2. a pulley 15 for winding a wire 21 for suspending the suction grill 2 is driven by a stepping motor 11. The period of step pulse supplied to the stepping motor 11 is changed so that the rotating speed can be arbitrarily changed. Thus, a speed reducing mechanism is not required and a torque transmission efficiency can be improved. Further, supplied current can be decreased, a power supply device such as a transformer can be made compact and cost can be lowered. During an overload state, a conditioning state is obtained. In this case, a superheat state as in a DC motor is not established, so that a lock protecting mechanism such as a limiter is not necessary. |
