Control device for an electrically powered foldable rearview mirror for automobiles
US5514940A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 26, 1995 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | May 26, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60R1/074
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The control device controls an electrically powered foldable rearview mirror in which a mirror body is reversibly rotatable around a shaft by an electric motor contained in the mirror body and in which the mirror body rotation is stopped in a predetermined erected position and folded position by rotation stop devices. The control device for controlling mirror rotation includes a switching circuit for switching the power supply connections to the motor to rotate the mirror body in one of two direction, a relay circuit for supplying and cutting off power to the motor and a relay control circuit connected to the relay circuit and the motor. The relay control circuit includes a resistance and a semiconductor device for switching the relay control circuit connected in parallel with the resistance to perform a switching operation when the motor driving electric current is increased due to a stoppage of the mirror body rotation which causes the voltage drop across the resistance to exceed a threshold voltage of the semiconductor device and to open or release the relay cutting off current to the motor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.