Electricity: motive power systems – Induction motor systems – Power-factor control
Patent
1981-02-05
1983-11-01
Smith, Jr., David
Electricity: motive power systems
Induction motor systems
Power-factor control
318812, H02P 540
Patent
active
044132174
ABSTRACT:
A power factor controller for AC induction motors having a control triac connected in series with the motor for controlling the voltage applied across the motor to reduce the power to the motor commensurate to motor loading. A sensing circuit produces square wave pulses representative of the phase difference between the current through the motor and line voltage across the motor. A reference circuit provides a reference signal representative of the full cycle of the pulse. A comparison circuit compares the output of the sensing circuit with the reference circuit and produces the phase lag signal for the control circuit. In a digital embodiment the sensing means and reference means each respectively control gated clocks whereby the count is representative of the duration of the pulse. In an analog version there is included an integration circuit which produces an output voltage level proportional to motor loading. A regenerative feedback circuit is coupled across the integration circuit and responds to turn on of the motor as well as application of sudden loads to the motor to provide full voltage to the motor.
REFERENCES:
patent: B458010 (1976-03-01), Sem-Sandberg
patent: 3663956 (1972-05-01), Purdy et al.
patent: 4099109 (1978-06-01), Abbondanti
patent: 4249120 (1981-02-01), Earle
patent: 4266177 (1981-05-01), Nola
"Improved Power-Factor Controller", NASA Tech. Briefs, Summer 1980, G. C. Marshall Space Flight Center, Ala. 35812.
Goldner Sandor
Green Dan
Cynex Manufacturing Corporation
Smith Jr. David
LandOfFree
Power factor controller does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Power factor controller, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Power factor controller will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2170491