| 摘要 |
PURPOSE:To allow operation of one type of motor for different power supply frequencies by controlling a machine to be controlled based on the discrimination results of a frequency discriminating means. CONSTITUTION:When the frequency is 50Hz, a frequency discrimination circuit 100 delivers a pulse signal P1 at a repetitive period of 20 msec. Since a pulse signal P4 is also delivered at same repetitive period, an overlapped interval is produced and during the overlapped interval, the output P5 from a NAND circuit 14 has 'L' level and sets an FF1 17 at a repetitive period of 20 msec. A pulse signal P. is delivered from the invert Q terminal of the FF1 17 to a transistor 21 but the 'H' level part of the pulse signal is not inputted because an integrating circuit 22 is provided and a fan motor serves as a 50Hz fan motor. In case of 60Hz, the invert Q output has 'H' level and the transistor 21 is turned OFF and thereby the fan motor serves as a 60Hz fan motor. |
