Variable threshold motor commutation pulse detection circuit
US6262546A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Jul 1, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P7/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved motor commutation pulse detection circuit for comparing a filtered motor current signal to a threshold value, where the circuit is responsive to the actual or expected amplitude of the commutation pulses for adjusting the motor current signal or the threshold value so that the compared threshold value is substantially equal in amplitude to minimum amplitude commutation pulses in the compared motor current signal. In one circuit, the threshold value is varied in accordance with the average current flowing through the motor at the time of the commutation event. In another circuit, the threshold is effectively switched between a high value and a low value depending on the mode of operation of the motor. A motor run detection threshold is activated during motor running periods, while a motor brake detection threshold is activated during motor braking. The run time detection threshold is set to a relatively high value to detect the relatively high amplitude commutation pulses that occur during motor running, while the brake detection threshold is set to a relatively low value to detect the relatively low amplitude commutation pulses that occur during motor braking. The thres…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.