Patent · US Expired

Stepper motor exciting circuit

US4476421A · kind A · utility

17Cited by
1References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 3, 1983
Grant dateOct 9, 1984
Priority date
Expiry dateMar 3, 2003

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02P8/12
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An exciting circuit for a stepper motor requiring only a single decoder device yet being capable of controlling the speed of the stepper motor using plural different modes of excitation. A memory stores digital data representing a predetermined sequence of activation of the exciting coils. A counter drives the address input port of the memory in accordance with its output count. A clock signal generator supplies clock pulses to the counter in one of two patterns, representative of high and low speeds. The first of the patterns contains clock pulses spaced at equal intervals with a frequency such that the stepper motor can follow the corresponding changes in activation of the exciting coils of the motor. In the second pattern, the clock signals are supplied in bursts, the internal frequency of which is higher than the stepper motor can follow. In this latter case, portions of the normal excitation sequence are effectively omitted, thereby driving the motor at a different speed.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.