Stepper motor controller
US6806675B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 4, 2001 |
| Grant date | Oct 19, 2004 |
| Priority date | — |
| Expiry date | Oct 4, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/22
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A stepper motor control circuit reduces ripple current by applying both fast and slow current decays to a motor phase when current is being reduced in the motor phase while following a falling current waveform. The control circuit uses an initial fast decay to reduce a winding current and then switches to a slow decay until a winding current is sampled again. The control circuitry samples a winding current and compares the sampled current to a reference current to determine if current is to be applied or reduced using fast and/or slow decay methods. Different phase current sample circuits allow either constant current sensing or selective current sensing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.