| 摘要 |
A power factor type motor controller in which the conventional power factor constant voltage command signal is replaced during a 5 to 30 second starting interval with a graduated control voltage. A ramp generator 174 provides an initial ramp-like signal which replaces a constant power factor signal supplied by potentiometer 70. The ramp-like signal is applied to terminal 40 where it is summed with an operating power factor signal from phase detectors 32, 34, and 36 to thereby obtain a control signal for ultimately controlling SCR devices 12, 14, and 16 to effect a gradual turn-on of motor 10. The SCR devices are turned on at an advancing rate with time in response to the summed or combination signal rather than simply as a function of a ramp-like signal alone, to thereby eliminate motor instabilities. |
