Microstepper motor control circuit PWM output coupled to H-bridge gates
US10084402B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 17, 2016 |
| Grant date | Sep 25, 2018 |
| Priority date | — |
| Expiry date | Oct 17, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A stepper motor control system includes stepper motor error reduction. For example, first and second power switches respectively energize and de-energize a stepper motor coil during each cycle for pulse-width modulating (PWM) the coil current. During a cycle including a zero crossing microstep, a calibrator detects a type of a body diode effect that occurs in the second power switch when the second switch stops de-energization of the coil. A selected offset is adjusted in response to the type of detection of the body diode effect of the second power switch. Adjusting the selected offset controls the trigger time for a comparator for comparing an offset reference voltage to a motor voltage developed in response to the coil current. Progressively adjusting the selected offset over successive cycles compensates for delays of components in the PWM control loop and reduces errors resulting from, for example, process, voltage, and temperature variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.