Circuit and method for controlling speed of an alternating current motor
US4465957A · kind A · utility
14Cited by
11References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 17, 1983 |
| Grant date | Aug 14, 1984 |
| Priority date | — |
| Expiry date | Feb 17, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of controlling the speed of an alternating current motor is disclosed. A direct current reference signal, the magnitude of which is proportional to the speed of an electric motor, is coupled to one input of a voltage comparator. A control pulse is generated at the beginning of each half cycle of the alternating current source and utilized to periodically discharge a timing capacitor. The voltage present on the timing capacitor is applied to a second input of the voltage comparator and when the timing capacitor voltage equals or exceeds the direct current reference signal, power is applied to the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.