The invention relates to a dual detector with a detection head (10), comprising:—a platform (11) and—an induction sensor fastened to the platform (11) and comprising a transmitter coil (12) and a receiver coil (13), the transmitter coil (12) and the receiver coil (13) each forming a loop, the loop of the transmitter coil (12) overlapping the loop of the receiver coil (13) at least partially so as to form a coupling zone (14), the coupling zone (14) being elongated in a first longitudinal direction defining a first axis (X.sub.1), the handle (20) extending in a plan (P.sub.1) normal to the platform (11) and the first axis (X.sub.1) of the coupling zone (14) being transverse to this plane (X.sub.1).

A foreign object detector includes detection coils between a transmitter coil in a transmitter device and a receiver coil in a receiver device, a power supply circuit that supplies AC power having a predetermined frequency to each detection coil through a feeder coil located to be electromagnetically coupled to each detection coil, and a detection circuit that detects, while power to be transmitted to the receiver coil is being supplied to the transmitter coil, a criteria voltage to be a criterion for foreign object detection output from each detection coil at a start of power supply from the power supply circuit and outputs a signal to stop power supply to the transmitter coil in response to the criteria voltage for any detection coil deviating from a predetermined range. The transmitter device transmits power to the receiver device contactlessly.

A metal detector apparatus having a balanced coil system, a receiver unit, a drive coil with at least one capacitor forming a series resonant circuit connected to a transmitter unit having a converter, and a drive controller. The metal detector apparatus configuration generates a first square wave signal set to a fixed/selectable operating frequency which is applied to a first drive switch connected on one side to a first voltage potential and on another side to a centre tap of a half-bridge circuit. A second square wave signal set is generated to the fixed/selectable operating frequency and is applied to a second drive switch connected on one side to a second voltage potential and on another side to the centre tap, via which a drive current is supplied to the drive coil.

The invention concerns a system (1) and a method for scanning a person (2) before access to a restricted access area (3), comprising a processing unit (14) and a metal detector (10, 70) for detecting metal in the shoes (20) or in a waist portion of the person walking on a surface (15). The processing unit controls an indication unit (12, 13) for: letting the person walk towards the restricted area if a first scan indicates the probability of the presence of metal lower than a first threshold; in case of a probability higher than the first threshold, prompting the person to carry out a second scan close to a mark (11) on the carpet; and prompting the user to remove his shoes or object if the first scan indicates a probability higher than a second threshold, or if the second scan indicates a probability higher than a third threshold.

A metal detection apparatus has a passage channel (100) through which products (P) that may contain metal contaminants (C) pass. The apparatus has at least one transmitter unit (1) that provides transmitter signals to a transmitter coil (2) that is inductively coupled to a first and a second receiver coil (31; 32). The receiver coils are balanced and connected separately or combined to an input of a receiver unit (4). The transmitter coil has at least two coil sections (211, 212; 221, 222) that are arranged inclined to one another, with each coil section generating at least a first and a second magnetic field (M.sub.y; M.sub.Z). Each of the first and the second receiver coils has at least a first coil section (311; 321) that is engaged in the first magnetic field and at least a second coil section (312; 322) that is engaged in the second magnetic field.

The present invention aims to provide a coil unit for improving an accuracy in detecting foreign matter and an apparatus for detecting foreign matter which improves the accuracy in detecting foreign matter when a power is transmitted in a contactless manner. A power feeding coil unit (a coil unit) of the present invention is provided with a power feeding coil (a coil for power transmission) and an apparatus for detecting foreign matter. The apparatus for detecting foreign matter is provided with a plurality of resonators having a resonator coil and a resonator capacitor and also an excitation coil for exciting the plurality of resonators. The plurality of resonators are disposed to cover at least an area interlinking with a magnetic flux generated by the power feeding coil and to decrease an influence of mutual inductance.

This invention relates to metal detectors used to detect metal targets in soils wherein the detector is insensitive to signals induced by a received magnetic field due to perpendicular components of a uniform conducting half-space, including metal detectors simultaneously capable of suppressing signals due to components of substantially log-uniform viscous superparamagnetic soil, and including metal detectors using repeating transmit signal cycles resembling a pulse induction-like waveforms. It discloses signal processing, in particular synchronous demodulation functions which may simultaneously substantially suppress signals due to perpendicular components of a uniform conducting half-space in a received magnetic field, signals due to components of substantially log-uniform viscous superparamagnetic soil, and signals due to a movement of the receive coil with respect to a static magnetic field.

The present invention relates to a portable metal detector adapted for detection of dangerous metallic items carried by individuals, for example during access to a departure lounge in an airport, comprising a casing which houses a transmitter/receiver winding, the casing being extended by a gripping and handling handle, and a processor which feeds a loop of the winding to generate a magnetic field and which detects perturbations of the magnetic field caused by the environment, characterised in that the detector comprises a sensor for detecting orientation of the detector in a vertical position of the handle and which, when the detector is in a vertical position, activates a single dynamic detection mode of the winding whereas, when the detector is in another position, it activates a static operating mode of the winding.

An apparatus for detecting objects includes a transceiver configured to generate a radar signal, a radar having a transmit antenna configured to transmit the radar signal, and a receive antenna configured to sense a return signal in response to a transmission of the radar signal. The apparatus also includes a processor configured to detect an object based on the return signal. One or more of the transmit antenna or the receive antenna include offset spiral feed antennas.

In accordance with some embodiments, an antenna is presented. In some embodiments, an antenna includes a plurality of coil arrays arranged along a core; and a switch coupled to each of the plurality of coil arrays, the switch connecting the plurality of coil arrays in one of a plurality of configurations in response to one or more sensitivity control signal.