Motor control circuit for automatic washer
US4972134A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 2, 1988 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | May 2, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control circuit for operating a permanent split capacitor motor from an ac source. The motor control circuit causes the motor to accelerate and decelerate according to a velocity profile. A driver circuit connects the motor to the ac source. The driver circuit receives a pulse signal at a predetermined time point after a zero crossing of the ac source and connects the ac line current to the motor at the predetermined time point, then the driver circuit disconnects the ac source from the motor at the next zero crossing of the ac source. A ramp wave signal is generated, each ramp thereof beginning at a zero crossing of the ac source and a dc voltage representative of the speed of the motor is also generated. A velocity profile having a predetermined period is provided on an output of a velocity profile generator. A first comparator circuit has a first input for receiving the dc voltage and a second input for receiving the velocity profile. An error signal is provided on an output thereof. A second comparator has a first input receiving the ramp wave signal and a second input receiving the error signal. An output signal is provided on an output thereof to a monostable circuit …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.