Stepper motor control circuit and apparatus
US4803415A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1987 |
| Grant date | Feb 7, 1989 |
| Priority date | — |
| Expiry date | Oct 7, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a motor control circuit for a stepper motor which causes a motor shaft to oscillate between an incremental rotational position nearest above and nearest below a commanded average rotational position identified by an electrical command signal. A clock is provided for sending periodic clock signal pulses to the control circuit. An up/down counter is connected to the clock for counting clock pulses on each clock cycle and for providing an output signal in the form of a binary representation of total clock pulses. A comparing circuit electrically connected to the up/down counter is used to control an up/down direction of the up/down counter before each clock signal pulse so that the up/down counter causes the motor shaft to rotate to a position nearest beyond the commanded shaft position and to thereafter oscillate between an incremental count nearest above and an incremental count nearest below the commanded average rotational position. The invention provides the benefit of greater average shaft position resolution and, additionally, because oscillation is provided, the present invention is particularly useful in the electrical positioning of valve spo…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.