Over-temperature protection circuit for power devices
US9024549B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2011 |
| Grant date | May 5, 2015 |
| Priority date | — |
| Expiry date | Jan 19, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P29/032
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An over-temperature protection circuit for a direct current (DC) electric tool includes a current detecting circuit electrically coupled to a battery pack, a power device control circuit electrically coupled to an electric motor of the DC electric tool and a power device for controlling the power state of the circuit. A computation control circuit controls the power supply of the motor according to the circuit current value detected by the current detecting circuit. When the electric motor is not in a speed control state, the allowable current passing through the over-temperature protection circuit of the DC electric tool cannot exceed a preset first current value. When the electric motor is in the speed control state, the allowable current passing through the over-temperature protection circuit of the DC electric tool cannot exceed a preset second current value less than the first current value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.