A foreign matter detecting device includes a plurality of detection coils disposed so as to be capable of being electromagnetically coupled to each other between a transmission coil of a power transmission device and a reception coil of a power reception device between which power is transmitted in a non-contact manner, a plurality of capacitors each forming a resonance circuit together with each of the plurality of detection coils, a power supply circuit supplying AC power having a predetermined frequency to an input coil that is one of the plurality of detection coils, and a detection circuit detecting a voltage of AC power transmitted via the plurality of detection coils from an output coil that one of the plurality of detection coils and is different from the input coil, and detecting foreign matter entrapped between the transmission coil and the reception coil according to the voltage detected.

Provided is a technique for detecting a vehicle type and a traveling direction of a vehicle by an electromagnetic induction sensor.

A sensor unit (10), which is an electromagnetic induction sensor, includes a transmission coil (TX1), a first reception coil (RX1), and a second reception coil (RX2). A magnetic field of a vehicle (90) made of steel attracts a magnetic field emitted from the transmission coil (TX1) (S1). As the vehicle (90) approaches, a state 1 indicated by the broken line changes to a state 2 indicated by the dash-dot line (S2). A reduction in induced voltage and a phase change occur with respect to the induced voltage when the first reception coil (RX1) is in the magnetic field of state 1 (when the vehicle is not detected) (S3). The differential output signals of the second reception coil RX2 and the first reception coil RX1 change according to the advancement of the vehicle and according to the unevenness of the vehicle bottom portion 92 and the metal species (S4). The trajectory image representing a differential output signal in rectangular coordinates of a reception level and a phase difference is different for each vehicle, so the vehicle type may be distinguished.

A fluxgate detector for buried and abandoned chemical weapons is provided, comprising: a probe for sensing an external magnetic field, comprising a probe input and a probe output; an excitation module electrically connected to the probe input for inputting an excitation signal into the probe; a frequency selection module electrically connected to the probe output for isolating a second harmonic signal in an induced voltage generated by the probe; and a signal acquisition module electrically connected to the frequency selection module. The second harmonic signal in the induced voltage can be isolated by the frequency selection module, transmitted to the signal acquisition module, and converted to an intensity of the magnetic field by the signal acquisition module. The substance detected can be identified according to the intensity of the magnetic field, so that the buried ACWs can be found efficiently and accurately.

The invention relates to a system for detecting the crossing of a vehicle, including: a primary set of coils, of rank 1 to N and arranged in a particular layout, a secondary set of coils, of rank 1 to N, arranged in the same particular layout, a primary power supply and measurement device connected to each coil of the primary set so as to supply power to and measure the inductance of each coil, a secondary power supply and measurement device connected to each coil of said secondary set so as to supply power to and measure the inductance of each coil, wherein each secondary power supply and measurement device is synchronized with the primary power supply and measurement device, a storage device for recovering information relating to the number of vehicles detected by each set.

A metal detector and method of operation are disclosed, wherein the metal detector includes 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 generating: a first square wave signal set to a fixed/selectable operating frequency and 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, and a second square wave signal set to the fixed/selectable operating frequency 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.

A metal detection system includes a detection module, a control module, a positioning module, and a computer module. The detection module includes an electromagnetic wave emitter that emits electromagnetic waves, and an electromagnetic wave receiver that senses electromagnetic signals emitted by underground metal in response to the electromagnetic waves emitted by the electromagnetic wave emitter. The control module processes the electromagnetic signals received by the electromagnetic wave receiver and generates metal detection data based on the received electromagnetic signals, or processes output signals provided by the detection module and generates metal detection data based on the output signals provided by the detection module. The positioning module generates information about positions of the metal detection device over time.

The invention relates to a system for detecting the crossing of a vehicle, including: a primary set of coils, of rank 1 to N and arranged in a particular layout, a secondary set of coils, of rank 1 to N, arranged in the same particular layout, a primary power supply and measurement device connected to each coil of the primary set so as to supply power to and measure the inductance of each coil, a secondary power supply and measurement device connected to each coil of said secondary set so as to supply power to and measure the inductance of each coil, wherein each secondary power supply and measurement device is synchronized with the primary power supply and measurement device, a storage device for recovering information relating to the number of vehicles detected by each set.

A sensor apparatus for detecting a target object is provided, together with a corresponding method for operating the sensor apparatus. The sensor apparatus comprises a transmitter device which is operated by periodic excitation signals at a basic frequency, a receiver device which couples to the transmitter device, wherein the coupling is dependent on a relative position of the target object with respect to the receiver device, and the receiver device delivers signals at the basic frequency which are dependent on the relative position of the target object with respect to the receiver device. A threshold value checking device checks whether signals lie within or outside a threshold value range. A linking device acts on signals from the receiver device or signals derived therefrom in such a way that signals or signal combinations are shifted into the threshold value range insofar as they previously lay outside this range.

A device (10) for detecting electrically conducting objects to be measured in a ground is provided, including a housing (21), a solenoid unit (34) situated in the housing (21), which includes a transmitter coil unit (38) and a receiver coil unit (39), a control unit (36), and an evaluation unit (37). A metal sheet (35) is provided in the housing (21), the solenoid unit (34) being situated on a lower side (53) of the metal sheet (35) facing the ground during the measuring operation, and the control unit (36) being situated on an upper side (54) of the metal sheet (35) facing away from the ground during the measuring operation.

An intruding metal detection method for a supplying-end module of an induction type power supply system having a supplying-end coil includes interrupting at least one driving signal of the induction type power supply system to stop driving the supplying-end coil during a measurement period, to generate a coil signal of the supplying-end coil; measuring a plurality of peaks of the coil signal within a plurality of consecutive oscillation cycles of the coil signal, to obtain a plurality of peak trigger voltages, respectively; calculating a first attenuation parameter according to a first peak trigger voltage and a second peak trigger voltage among the plurality of peak trigger voltages; and comparing the first attenuation parameter with a first threshold value to determine whether there is an intruding metal existing in a power supply range of the induction type power supply system.