Position control and monitoring circuit and method for an electric motor
US6031350A · kind A · utility
Inventor
Key dates
| Filing date | Mar 17, 1998 |
| Grant date | Feb 29, 2000 |
| Priority date | — |
| Expiry date | Mar 17, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/42237
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A position control and monitoring circuitry is provided for an electric motor having a plurality of coils and a movable element. A drive circuit generates a square wave drive signal of variable mark/space ratio to drive the coils to position the movable element. A monitoring circuit modulates square wave transitions at a sub-harmnonic of the drive signal frequency and generates a monitoring signal for injection into the coils. A sensor senses the monitoring signal from the coils to determine the position of the movable element. A difference circuit drives the drive circuit with a difference between an input signal and an output signal of the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.