Patent ID: 8493074

Claim:
An electrical hand-held device that can be placed on a surface, comprising at least a transmission electrode, a reception electrode and a compensation electrode arranged between the transmission electrode and the reception electrode, with which an approach of a hand to the hand-held device is detectable, wherein from the transmission electrode a first alternating electric field and from the compensation electrode a second alternating electric field can be radiated wherein the first alternating electric field with respect to the second alternating electric field is phase-delayed and wherein the alternating electric fields can be coupled into the surface and into the reception electrode, wherein the alternating electric fields coupled to reception electrode generate a current in the reception electrode that is representative of an approach of a hand to the hand-held device, wherein the transmission electrode and the reception electrode on the hand-held device are arranged so that the sum of the impedances between the transmission electrode and the reception electrode that consist of the impedance between the transmission electrode and the surface, the impedance of the surface and the impedance between the surface and the reception electrode when a hand-held device is placed on the surface exceeds a predetermined value that is suitable to keep the current generated in the reception electrode under a predetermined value.