Patent · US Active

Detection of a metal or magnetic object

US9304107B2 · kind B2 · utility

0Cited by

1References

10Claims

0Family size

Assignee

Robert Bosch GmbH · DE

Inventors

Tobias Zibold · Stuttgart, DE
Andrej Albrecht · Stuttgart, DE

Key dates

Filing date	Mar 8, 2011
Grant date	Apr 5, 2016
Priority date	—
Expiry date	Jan 25, 2033

Classification

Technology area (CPC G)Physics
CPC primaryG01V3/104
WIPO fieldMeasurement
WIPO sectorInstruments

Abstract

A measuring device configured to detect a metal object includes two emission coils configured to produce superimposed magnetic fields. The measuring device also includes a device configured to determine a differential voltage between the emission coils. The measuring device further includes a control device configured to supply the emission coils with alternating voltages such that the value of an AC voltage component of the differential voltage, which is time synchronized with the alternating voltage, is minimized. The control device is configured to detect the metal object when the ratio of the alternating voltages does not correspond to the ratio of the impedances of the emission coils when the metal object is not there.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.