| 摘要 |
1,099,660. Control of A.C. motors. GENERAL ELECTRIC CO. Nov. 28, 1966 [April 27, 1966], No. 53200/66. Heading H2J. A reversible two-phase induction motor 100 has a control winding supplied sinusoidally from A.C. source 90 through power transistors Q5- Q 8 which are pulse-controlled by transistors Q 1 -Q 4 . A source 10 responds to a servo command and a feedback signal from transformer T 9 to provide a variable amplitude, bi-polarity, D.C. signal to saturable transformers T 1 -T 4 whose cores have matched square-loop hysterisis characteristics to provide integration. Square-wave signals are applied to the transformers, synchronized with the A.C. power, and having the same frequency. A D.C. bias is also applied to the transformers. Transformers T 1 , T 2 provide control action for a first half-cycle, and transformers T 3 , T 4 , control the second half-cycle, diodes CR 1 -CR 4 affording this division of control. As the signal from source 10 deviates from zero, a voltage is developed across resistor R 5 connected to summing resistors R 1 , R 2 , and is applied to the bases of transistors Q 1 , Q 2 to render one of the power transistors Q 5 , Q 7 conductive. When a negative signal is produced at resistor R 6 by summing resistors R 3 , R 4 , transistor Q 4 conducts and transistor Q 6 is driven to connect power to the motor during the second halfcycle for a set period. Diodes CR 5 -R 8 are poled to permit the desired current-flow. |
