Burn-out preventive circuit for commutatorless motor
US4578623A · kind A · utility
17Cited by
2References
10Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 21, 1984 |
| Grant date | Mar 25, 1986 |
| Priority date | — |
| Expiry date | May 21, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/00
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A burn-out preventive circuit for a commutatorless motor comprises drive windings of two phases, driving power transistors connected in series with the drive windings respectively, a position detecting element detecting the angular position of rotation of a permanent magnet rotor for alternately turning on the driving power transistors, and a protective circuit detecting a counter-electromotive force induced in the drive windings during rotation of the permanent magnet rotor for interrupting energization of the drive windings when the detected counter-electromotive force is lower than a predetermined level or zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.