| 摘要 |
PURPOSE:To prevent the motor characteristics from varying due to the difference of power frequency by varying the energizing time in response to the discriminated power frequency. CONSTITUTION:When a counter 2 is formed, for example, of an octal counter, an output is produced at a synthesizer until the counted value becomes ''7''. When it becomes ''8'', the outpt is stopped. When it becomes ''9'', it is reset, and the outputs at the counter values ''1'' and ''7'' are acted to the motor 8 as DC component at the brake side. The motor 8 is driven by the output at 60Hz by a discriminator 5, and is fully conducted at 50Hz. In this manner, the motor can perform the same characteristic even in both 60 and 50Hz of commerical powe souce frequency, thereby eliminating the complicated pulley exchange conducted heretofore. |
