BEMF rectification during power off to prevent parasitic effect
US5883479A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 1, 1997 |
| Grant date | Mar 16, 1999 |
| Priority date | — |
| Expiry date | Jul 1, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit and method to clamp a node of a power device connected to a driving node of a polyphase d-c motor to a reference potential during a powering off of the drive includes a current mirror and a comparator. A first input of the comparator is connected to the reference potential, and a second input is connected to the driving node. The reference potential may be a ground potential, or, preferably, the potential at another driving node of the motor. An output of the comparator is connected to a first side of the current mirror. A circuit is connected to apply a current reflecting the output of the comparator to a low side driver connected to the node.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.