Variable motor speed control for automatic washer
US4950969A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1989 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Jun 12, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A variable speed control is provided for controlling a reversing permanent split capacitor motor in an automatic washer. The operation of the motor is controlled such that the motor will accelerate for a first predetermined time period and then coast with no power applied for a second predetermined time period. This generalized operation of the motor occurs in the spin cycle. In the agitate cycle, a logic decoding circuit uses a tach pulse signal indicative of the speed of the motor to provide a time for the motor to be on, and utilizes an AC line current zero crossing signal from a zero crossing detector to establish a time during which the motor is off, the motor on plus off time establishing a stroke rate for the agitate cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.