Circuitry for determining actuator position
US6078154A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1999 |
| Grant date | Jun 20, 2000 |
| Priority date | — |
| Expiry date | Feb 12, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/909
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Circuitry (100, 100') for determining actuator position includes four MOS transistors (T1-T4) connected to each side of a bi-directional motor (10). The current flowing through the motor (10) at any given time is proportional to voltages developed across the internal impedances of the transistors (T1-T4). The resulting motor voltages are amplified and high-pass filtered to remove any DC offsets due to the signal amplification. The conditioned motor voltages are then compared to one or more threshold voltages and passed through a one shot circuit (120) to provide detectable pulses for each motor commutation event. Circuitry (106,107) is provided for counting pulses provided by the one shot circuit (120) and, based on a desired motor position, for providing a number of digital control signals to a digital control circuit (104). Digital control circuit (104) is responsive to the number of digital control signals to control the gate voltages of the four transistors (T1-T4) to thereby control the position of the motor (10).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.