Limited-pool random frequency for DC brush motor low frequency PWM speed control
US6674962B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 29, 2002 |
| Grant date | Jan 6, 2004 |
| Priority date | — |
| Expiry date | Apr 7, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/29
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control system 10 includes an engine cooling module 14 including a DC motor 12. The system includes a switch 18 constructed and arranged to be controlled by a pulse width modulated (PWM) signal 26. The switch 18 is operatively associated with the DC motor to control current to the DC motor and thus control the speed of the DC motor. A controller 20 is operatively associated with the switch. The controller is constructed and arranged to select periods, of a limited-pool of frequencies each being less than 500 Hz, from a pseudo-random sequence of periods and to send the selected periods to the switch, thereby controlling noise and vibration of the module.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.