Apparatus for DC motor position detection with capacitive ripple current extraction
US7064509B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2005 |
| Grant date | Jun 20, 2006 |
| Priority date | — |
| Expiry date | Mar 14, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/0094
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An apparatus for determining angular positions of DC motor includes a capacitor connected in parallel with the DC motor. The current flowing through the capacitor, at any given time, is an AC ripple current responsive to a commutation event of the DC motor. The capacitor partially sources the motor current ripples during commutation and recharges itself during the off-commutation period. Since the number of commutation events per mechanical revolution is pre-determined once the DC motor is designed, the frequency of the AC ripple currents through the capacitor corresponds to the frequency of commutation, and thus a motor position of the DC motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.