Detection of a dielectric object

US9310454B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

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

Key dates

• Filing date: Mar 10, 2011
• Grant date: Apr 12, 2016
• Expiry date: Jun 14, 2032

Classification

• Technology area (CPC H): Electricity
• CPC primary: H03K17/955
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A measuring apparatus for detecting a dielectric object comprises a potential probe for determining an electric potential in an electric field, a first capacitance device, a second capacitance device, and a control device configured to supply alternating voltages to the first and the second capacitance devices. The control device is configured to amplify the alternating voltages in opposite directions to one another in order to minimize the magnitude of an AC voltage component, which is clock-synchronous with the alternating voltages, of a voltage which is recorded by means of the potential probe. The dielectric object is detected when a ratio of the alternating voltages does not correspond to a ratio of (i) a first distance of the potential probe from the first capacitance device to (ii) a second distance of the potential probe from the second capacitance device.