| 摘要 |
PROBLEM TO BE SOLVED: To control not only a compressor but also a fan motor in a refrigerator and a machine room fan motor at a variable speed responsive to a load of the compressor by commonly giving a chopper signal to a switching element for driving the motor in the refrigerator. SOLUTION: When a duty of a chopper signal is large, output power of a switching element 3 for a compressor also becomes large, and a rotational speed of the compressor 9 can be accelerated. And, in the case of a switching element 4 for a fan motor in the refrigerator receiving the same signal, since a transistor 12 is turned ON when the signal is 'H', rotational speeds of a fan motor 10 in the refrigerator and a fan motor 11 in a machine room are accelerated when the duty is large. Meanwhile, if the duty is small, the rotational speeds of both the motors 10, 11 are decelerated. That is, even at the time of using a general voltage doubler rectifier 2, the motors 10, 11 can be controlled at variable speed responsive to the rotational speed of the compressor 9 without almost increasing its cost. |
