Power factor controller
US4413217A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1981 |
| Grant date | Nov 1, 1983 |
| Priority date | — |
| Expiry date | Feb 5, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E40/30
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.