Brushless D-C motor system with improved commutation circuit
US4535275A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 7, 1982 |
| Grant date | Aug 13, 1985 |
| Priority date | — |
| Expiry date | Dec 7, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P2209/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
To provide for reliable commutation of a single-strand or single-line winding (25) connected in the diagonal of a transistor bridge circuit (40, 40') having four transistors (70-73) which are alternately rendered conductive in accordance with a Hall-IC rotor position sensor (32) affected by the field of a permanent magnet rotor (13), time delay capacitors (64, 66; 87) are connected to charge current sources, for example high-resistance resistors (59, 63; 88, 90, 95) to delay turn-ON of respective transistors of the bridge permitting current flow through the winding in a first direction after commutation from the other transistors (71, 72) of the bridge which are being turned OFF or blocked, so that a finite time interval or gap of no current flow is provided to reliably prevent possible short-circuit currents across the power supply buses (44, 45) if the inherent switching characteristics of the transistors are longer than the commutation interval. The capacitors are connected to a rapid-discharge circuit, for example through diodes (62) or the inherent semiconductor, such as a transistor (54) in a Hall generator-integrated circuit combination. If transistors of inherent sufficient…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.