Electrical power tool for operating with alternating current
US8692525B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 2008 |
| Grant date | Apr 8, 2014 |
| Priority date | — |
| Expiry date | Mar 18, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to an electrical power tool, particularly an electric hand power tool, for operating with alternating current, having an electric motor, and electronic control device, and an electrical power switch for actuating the electric motor, wherein the electronic control device comprises a bias voltage output and a detection input, connected to each other by means of a voltage divider comprising a summation point and to the side of the power switch facing the electric motor, and the control device is further designed such that the potential at the detection input is monitored after actuating the power switch and used for checking whether the power switch is conducting, and that it is actuated again if the power switch was not conducting or returned to the non-conducting state during the monitoring, and that said checking and any renewed actuation of the power switch is repeated within a half-wave of the alternating voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.