Variable speed control switch for direct current electric power tools
US5892885A · kind A · utility
30Cited by
15References
17Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 12, 1998 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | May 12, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/937
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A motor control circuit for a power tool includes a function switch which has a first battery contact, a speed control contact, a bypass contact and, a second battery contact connected in that order in a line. The function switch also has a movable contact which sequentially connects the first battery contact to the bypass contact, the speed control contact to the second battery contact, and the bypass contact to the second battery contact. A solid state switch has conduction path connecting the speed control contact to the second motor terminal wherein the conduction path is controlled in response to an oscillator signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.