Motor speed control system
US4680516A · kind A · utility
15Cited by
8References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 30, 1986 |
| Grant date | Jul 14, 1987 |
| Priority date | — |
| Expiry date | May 30, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/912
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor speed control system comprises an encoder (12) which produces a series of indicator pulses related to the motor's speed. The period of the pulse is compared with that of a crystal-controlled reference period produced by a period generator (14). Comparison is made by means of a period comparator (16) consisting of logic elements, including flip-flops (F1, F2, F3) and gates (G1 and G2). Digital outputs of the period comparator control UP and DOWN charge pumps whose integrated value controls the motor through a power driver. Advantages of the system are precise digital control with crystal accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.