A radio frequency (RF) weak magnetic field detection sensor includes a ferromagnetic core, a pickup coil disposed to surround the ferromagnetic core, a substrate that includes an opening, a core pad connected to the ferromagnetic core and a coil pad connected to the pickup coil, and an insulating tube interposed between the ferromagnetic core and the pickup coil. The insulating tube includes a bobbin around which the pickup coil is wound, and a core hole formed to pass through the bobbin and configured to accommodate the ferromagnetic core.

Wireless occupancy sensors and methods for using the same are provided. In some embodiments, a occupancy sensor comprises: a housing that includes a window positioned at a top portion of the housing; a battery at a lower portion of the housing; a first magnetometer that detects changes in a magnetic field when a vehicle moves over the first magnetometer; an optical sensor that detects one or more objects in a field of view of the optical sensor through the window; a transmitter for transmitting sensor data to a gateway device, and a processor that controls the first magnetometer, the optical sensor, and the transmitter.

Wireless occupancy sensors and methods for using the same are provided. In some embodiments, a occupancy sensor comprises: a housing that includes a window positioned at a top portion of the housing; a battery at a lower portion of the housing; a first magnetometer that detects changes in a magnetic field when a vehicle moves over the first magnetometer; an optical sensor that detects one or more objects in a field of view of the optical sensor through the window; a transmitter for transmitting sensor data to a gateway device, and a processor that controls the first magnetometer, the optical sensor, and the transmitter.

A magnetic sensor device for detecting linear movement of a moving body includes a magnetic field generation unit and a magnetic field detection unit, which is provided to be capable of detecting the magnetic field generated by the magnetic field generation unit. The magnetic field detection unit is provided to be relatively moveable along a first axis accompanying linear movement of the moving body. The first axis is parallel to the direction of movement of the moving body. The magnetic field generation unit includes a first magnetic field generation unit and a second magnetic field generation unit. The first magnetic field generation unit and the second magnetic field generation unit are arranged substantially parallel to the first axis. A first line segment parallel to a first magnetization direction of the first magnetic field generation unit is inclined with respect to a second axis orthogonal to the first axis. A second line segment parallel to a second magnetization direction of the second magnetic field generation unit is inclined with respect to the second axis. The first line segment and the second line segment are positioned symmetrically with respect to the second axis and intersect each other to open toward the first axis.

A demarcating system for indicating the boundary of an area to an object (for example a robot, such as a robotic lawnmower), which has a receiver for receiving electromagnetic signals. The system includes a control system, a wire loop, a signal generator, and current sensing circuitry. The wire loop can be arranged by a user along a path, so as to indicate the path to the object as part of a boundary of the area. The signal generator is under the control of the control system with the voltage signals applied by the signal generator to the wire loop being controlled by the control system. The current sensing circuitry senses current signals present within the wire loop and the processors of the control system analyse such current signals. The processors of the control system are programmed to operate in a calibration mode whereby they: cause the signal generator to apply a series of test voltage waveforms to the wire loop, each of the test voltage waveforms generating a corresponding current waveform within the wire loop; and analyse the series of corresponding current waveforms, as sensed by the current sensing circuitry, so as to determine an operating voltage waveform that, when applied to the wire loop, generates a corresponding operating current waveform that is substantially the same shape as a predetermined current waveform.

A magnetic sensor device includes at least one magnetic sensor and a support. A center of gravity of an element layout area of the at least one magnetic sensor is deviated from a center of gravity of a reference plane of the support. The at least one magnetic sensor includes four resistor sections constituted by a plurality of magnetoresistive elements. Magnetization of a free layer in each of two of the resistor sections includes a component in a third magnetization direction. The magnetization of a free layer in each of the other two resistor sections includes a component in a fourth magnetization direction opposite to the third magnetization direction.

A measuring apparatus for measuring losses in a circumferential segment for an electrical machine is provided. The measuring apparatus includes a frame to which a circumferential segment is fixable and a flux element attached to the frame so that a circumferential segment fixed to the frame and the flux element are radially distanced and that a magnetic flux generated by a current flowing along the coil windings housed in one slot of the circumferential segment follows a magnetic flux path including at least a first path portion in one tooth circumferentially adjacent to the one slot, a second path portion in the yoke, a third path portion in the other tooth circumferentially adjacent to the one slot and a fourth path portion in the flux element.

Various embodiments of the teachings herein include an apparatus for measuring a magnetic field of a conductor of an electric current. The apparatus may include three magnetic field sensors arranged on a circumference of a non-circular ellipse defined by parallel projection or orthogonal projection of a circle. Three first positions are arranged equidistantly on a circumference of the circle. The three first positions emerge from the parallel projection or the orthogonal projection onto at least three second positions on the ellipse. The three magnetic field sensors are arranged at the three second positions. The magnetic field is measured without using a flux concentrator.

A magnetic sensor device includes first and second surfaces, and first and second inclined surfaces, which are inclined with respect to the first surface; first through third magnetic sensor units for detecting magnetism in first through third axial directions; and a signal processing unit that performs signal processing on the basis of first through third sensor signals output from the first through third magnetic sensor units. The first axial direction is a direction orthogonal to the first surface, and the second and third axial directions are directions orthogonal to each other on the first surface. The first and second magnetic sensor units are provided on the second inclined surface, respectively. A corrected signal generation unit included in the signal processing unit generates first and second corrected signals, which are the first and second sensor signals corrected in accordance with the inclination angles of the first and second inclined surfaces.

Example embodiments of the present invention provide a magnetic relaxometry measurement apparatus, comprising: a magnetizing system configured to supply a pulsed magnetic fields to a sample; a sensor system configured to detect magnetic fields produced by induced magnetization of the sample after a magnetic field pulse from the magnetizing system; one or more compensating coils configured to suppress generation of eddy currents in an environment surrounding the apparatus due to the pulsed magnetic fields.