Capacitive obstacle detector for vehicles in reverse gear
US4887066A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1987 |
| Grant date | Dec 12, 1989 |
| Priority date | — |
| Expiry date | Jun 11, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C3/00
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The capacitive proximity sensor for motor vehicles comprises a capacitance-measuring device for measuring the capacitance between at least one capacitor plate (1) which is fixed to the motor vehicle, on the one hand, and the environment, on the other hand, and an indicator for receiving the output signal of the measuring device. To provide a proximity sensor in which the disturbing and parasitary capacitances occurring in practice are particularly taken into account, the output signal S.sub.c of the capacitance-measuring device (5) is delivered to an amplifier (6), which is provided with a degenerative feedback loop (9) comprising a storage device (11) and a switch (10) so that the output signal (s.sub.A) of the amplifier (6) is held constant during normal travel, and the switch (10) is opened to interrupt the degenerative feedback loop (9) for a measurement. The switch is closed when the measurement has been completed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.