Sensor-less circuits and related methods for back EMF zero crossing detection
US11165374B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Apr 1, 2020 |
| Grant date | Nov 2, 2021 |
| Priority date | — |
| Expiry date | May 14, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/187
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A sensor-less detection circuit includes a first voltage adjustment circuit providing a first output voltage at a first node using one of three input voltages. A second voltage adjustment circuit provides a second output voltage at a second node using all three, or only two, of the three input voltages. The second voltage adjustment circuit acts as an internal virtual neutral point for detecting a zero crossing event of the motor. A differential amplifier is coupled with the first and second nodes and outputs a third output voltage at a third node. A reference buffer has a reference voltage input and provides a fourth output voltage at a fourth node. A comparator is coupled with the third and fourth nodes and outputs a fifth output voltage at a fifth node, the fifth voltage indicating a zero cross event.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.