Abstract: A system for current measurement and ground fault detection is disclosed. In embodiments, the system includes a plurality of phase current measurement coils configured to detect phase currents associated with at least one portion of a multi-phase system. The system further includes a plurality of phase current measurement circuits and a ground fault detection circuit connected to the phase current measurement coils. The phase current measurement circuits are configured to measure the phase currents detected by the phase current measurement coils, and the ground fault detection circuit is configured to measure a summation of the phase currents detected by the phase current measurement coils.

Abstract: A linear position detecting device applied to a linear motion system for motion measurement is provided. The linear position detecting device comprises a coding element and a detecting element corresponding to the coding element for retrieving the signal of the coding element to provide the position information. The coding element comprises a base, a first coding unit and a second coding unit wherein the base comprises an axial direction parallel to a length of the base, and a radial direction perpendicular to the axial direction. The first coding unit is configured on the base and comprises a plurality of first tracks extended along the axial direction and alternately arranged along the radial direction. The second coding unit is configured on the base and adjacent to the first coding unit, and comprises a plurality of second tracks wherein the second tracks are extended along the radial direction and alternately arranged along the axial direction.

Abstract: An elongate component such as a drill string of drill pipes connected by joint sections inside a bore is sensed using at least one set of electromagnetic coils, the coils within the set being arranged at different angular positions around the bore facing the bore. There may be at least two sets of coils separated along the axial direction of the bore. Electrical oscillations are generated in the coils to produce oscillating electromagnetic fields that interact with the contents of the bore. A parameter of the electrical oscillations generated in each coil is detected. The detected parameters may be used to derive both (1) a measure of the axial position along the bore, and (2) a measure of the lateral position. The detected parameters may be used to derive a measure of electromagnetic properties of the contents of the pipe in a region adjacent each coil, thereby imaging the contents of the pipe.

Abstract: Herein provided is a phonic wheel for use in a gas turbine engine and associated systems and methods. The phonic wheel comprises a circular disk having first and second opposing faces. The circular disk defines a root surface that extends between and circumscribes the first and second faces. A first plurality of projections extend from the root surface and are oriented substantially parallel to an axis of rotation of the disk. The first plurality of projections are circumferentially spaced substantially equally from one another and each have a first physical configuration. At least one second projection extends from the root surface and is positioned between two adjacent first projections, the at least one second projection having a second physical configuration different from the first physical configuration.

Abstract: A linear actuator includes a piston, a transmitter, and a receiver. The piston is configured to linearly extend and retract (such as within a cover tube). The transmitter is configured to generate a transmit electromagnetic waveform and direct the transmit electromagnetic waveform along a length of the piston. The receiver is configured to receive a return electromagnetic waveform that includes the transmit electromagnetic waveform after travelling to an extended end of the piston and returning to the receiver and determine a position of the piston based on a phase difference between the transmit electromagnetic waveform and the return electromagnetic waveform.

Abstract: A proximity sensor that outputs presence or absence of a detection object or a position of the detection object as a detection result includes: a detection part configured to include a detection coil and a capacitor; an oscillation circuit configured to excite the detection part; an analog/digital conversion circuit configured to detect a signal change occurring in the detection part and output a digital signal indicating the detected signal change; a temperature detection part configured to detect a temperature inside a casing of the proximity sensor; a storage part configured to store a characteristic parameter unique to the proximity sensor in advance; a control calculation part configured to process a digital signal from the analog/digital conversion circuit to calculate a signal indicating a distance to the detection object, compensate the calculated signal using the characteristics parameter stored in the storage part, and output the compensated signal as the detection result.

Abstract: A display apparatus includes a display panel configured to display an image by emitting light, and a sound generating device on a rear surface of the display panel. The sound generating device includes a bobbin, and a protection member on the bobbin.

Abstract: An injection control device controls a fuel injection valve driven by an electric power. The injection control device includes a current detection unit to detect a driving current supplied to a solenoid of the fuel injection valve, an identification unit to identify a theoretical model of the driving current in a state where a movable core moved by an electromagnetic force generated by the solenoid is at rest, and a state detection unit to detect a state of the movable core. The state detection unit detects the state of the movable core, based on a deviation between the driving current detected by the current detection unit and the theoretical model.

Abstract: A barrier alarm device for reducing the number of false alarms that may occur in a home or business security system. In one embodiment, a barrier alarm device, such as a door or window sensor, determines whether a barrier, such as a door or a window, has been opened, and determines whether a human being is inside a premises in proximity to the door or window. If a human being is inside the monitored premises when the door or window is opened, it indicates that the human being is authorized to be inside the monitored premises, and the barrier alarm device transmits a timed alarm signal to a central security panel, causing a security response to be generated by the central security panel if a predetermined time period elapses without a user canceling the security response.

Abstract: In some embodiments, a coil design system is provided. In particular, a method of providing an optimized position locating sensor coil design in presented. The method includes receiving a coil design; simulating position determination with the coil design to form a simulated performance; comparing the simulated response with the specification to provide a comparison; and modifying the coil design based on a comparison between the simulated performance and a performance specification to arrive at an updated coil design.

Abstract: A joint sensing system within an enclosure can include an electrical circuit through which a first current flows, where the first current creates a magnetic field, where the electrical circuit is disposed proximate to a joint of the enclosure. The system can also include a target disposed proximate to the electrical circuit, where the magnetic field induces a plurality of second currents to flow within the target. The system can further include a sensor that measures the plurality of second currents flowing within the target to generate a plurality of measurements. The plurality of measurements can indicate a width of the joint of the enclosure.

Abstract: The present embodiment relates to a lens driving device comprising: a housing; a bobbin disposed inside the housing; and a lower elastic member provided on the lower side of the bobbin and coupled to the bobbin and to the housing, wherein the lower elastic member comprises a first outer portion, which is coupled to the housing, a second outer portion, which is coupled to the housing and is spaced from the first outer portion, a first inner portion, which is coupled to the bobbin, a second inner portion, which is coupled to the bobbin and is spaced from the first inner portion, a first elastic portion, which connects the first outer portion and the first inner portion, a second elastic portion, which connects the second outer portion and the second inner portion, and an inner connecting portion, which connects the first inner portion and the second inner portion.

Abstract: A printed circuit board (PCB). The PCB comprises a non-conductive substrate and a plurality of conductive coil loops formed on the substrate, wherein the coil loops are asymmetric. The conductive coil loops are formed as a continuous metal trace on the substrate, the coil loops are symmetric with reference to a longitudinal axis of the PCB, the coil loops are asymmetric with reference to an axis transverse to the longitudinal axis of the PCB, wherein the distance between adjacent coil loops crossing the longitudinal axis on a first side of a center of an innermost coil loop are substantially equal, and the distance between adjacent coil loops crossing the longitudinal axis on a side of the center of the innermost coil loop opposite to the first side of the center of the innermost coil loop increase with each coil loop progressing outwards.

Abstract: To detect changes in the physical properties of an examination object as changes in a plurality of different oscillation frequencies using signals with the oscillation frequencies, a sensor circuit includes: an oscillation circuit (1) with a first resonant frequency; an oscillation circuit (2) with a second resonant frequency different from the first resonant frequency; and a detection circuit (4) that detects oscillation frequencies of the oscillation circuit (1) and the oscillation circuit (2).

Abstract: An inductive movement sensor is provided including: a transducer including a primary winding suitable for producing a magnetic excitation, and a secondary winding including at least one turn, suitable for applying an electromotive force across the terminals thereof in the presence of the excitation; and a target including at least one conductive pattern, the target being suitable for moving parallel to the transducer such as to cause variations in the surface of a portion of the pattern located opposite the at least one turn, thereby causing variations in the amplitude of the electromotive force induced in the secondary winding, in which the target-transducer distance is between 0.8 and 1.5 times the optimum target-transducer distance in terms of linearity, or the distance for which the linearity error of the curve representative of the variation in amplitude as a function of the surface variation is minimal.

Abstract: A display device, a door including the display device and a refrigerator including the door are provided. A display device includes: a frame configured to be rotatably mounted to a base object; a display panel mounted to the frame; a detector disposed in the frame, and configured to detect a movement of the frame and output a signal corresponding to the movement; and a controller configured to determine a movement state of the frame based on the signal, and control the display panel based on the movement state.

Abstract: Noncontact measurements of positions of electrically-conductive objects is achieved by placing two conductive coils formed by traces on printed circuit boards (PCBs) in the proximity of the object surface, energizing one of the coils (excitation coil) with alternating electrical current and measuring the amplitude of the voltage induced on the terminals of the second coil (sensing coil). The alternating magnetic field generated by the current in the excitation coil induces eddy currents in the object, which affect the amplitude of the voltage induced on the terminals of the sensing coil. The sensing coil voltage depends on the mutual position between the object and the sensing coil, allowing the object position measurement. The excitation coil is integrated into a series LCR circuit driven by an output of an adjustable gain amplifier at the resonance frequency. The adjustable amplifier gain is constantly adjusted to maintain the sensor sensitivity constant.

Abstract: A method for detecting a short circuit to ground or to the operating voltage of a signal line (11, 12) of a resolver (16) has the following steps: —measuring the potential of the signal lines (13a, 13b; 14a, 14b) of the receiver coil (18) with respect to ground at two sampling times (R and F) provided symmetrically at the middle of the excitation period; —calculating an offset value for a signal line pair (13a, 13b; 14a, 14b) by calculating the average value of the four measured values (UHR, ULR, UHF and ULF) for the associated receiver coil (17, 18); and —identifying a short circuit and the potential to which the short-circuited line is connected in that the offset value is compared to threshold values.

Abstract: A turbo rotation sensor includes a magnet magnetized with two different magnetic poles along a circumferential direction about a rotating shaft of a compressor wheel and provided at an end portion of the compressor wheel on the air intake side, and a sensor portion that is housed in a sensor hole formed on the housing, is arranged to face the magnet in a radial direction of the rotating shaft, and includes two magnetic field detecting elements capable of measuring variation in magnetic flux density caused by the magnet. The two magnetic field detecting elements are aligned in a direction parallel to the rotating shaft so that the respective detection axes are parallel to an axial direction of the rotating shaft. The rotational speed of the compressor wheel is detected based on a difference between the magnetic field strengths detected by the two magnetic field detecting elements.

Abstract: A machinery brake of an elevator includes a frame part including an electromagnet, an armature part, an inductive proximity sensor indirectly mounted to one of the following: the frame part, the armature part, and a target mounted to another of the following: the frame part, armature part. The machinery brake further includes, for establishing the indirect mounting: a temperature change compensation device mounted between the inductive proximity sensor and one of the following: the frame part, the armature part. Some aspects relate to a method for compensating a change in switching point of an inductive proximity sensor.

Abstract: An eddy current sensor for a rotary shaft and a rotary shaft apparatus. The eddy current sensor includes: a housing; one or more position detecting probes provided on the housing; and a rotating speed detecting probe provided on the housing. The eddy current sensor integrates the position detecting probe and the rotary speed detecting probe, such that while the eddy current sensor is detecting position displacement of the rotary shaft, the eddy current sensor may also simultaneously detect the rotating speed of the rotary shaft, which facilitates detecting and monitoring the rotary shaft more comprehensively. The detected position data and rotating speed data of the rotary shaft correspond to each other at any time, such that the working state of the rotary shaft may be analyzed more intensively.

Abstract: A rotor assembly (30) comprising a rotor (32) having an annular array of rotor blades (34), the rotor mounted to a shaft (38). A phonic wheel (40) coupled to the shaft. A speed sensor (44) axially aligned with the phonic wheel and configured to measure voltage (V), amplitude of the voltage being proportional to clearance (46) between the sensor and phonic wheel. A processor (48) configured to: receive the voltage measurement; derive shaft speed (?) from the voltage measurement; identify modulation of the voltage amplitude at a frequency which is an integer multiple of the shaft speed; compare voltage amplitude to a threshold; and output a rotor damage signal based on the comparison.

Abstract: A device that will increase an inductive proximity sensor's detection distance and detection position is disclosed. The device uses a housing in combination with a sensor and axially magnetized magnet and a target magnet to achieve the increased detection distance and position. The device can be defined as universal because it allows different manufacturers and sizes of sensors to be used and calibrated. An optional threaded end section of the device allows connection of standard conduit fittings.

Abstract: A compact resolver pre-amplification assembly has first and second printed circuit boards. The boards include an interface with an N/N?1 resolver and a resolver-to-digital converter and three signal paths. The first and second circuit boards are contained in a single package configured for mounting on a robotic joint while providing high amplification and noise rejection. Low level sensitive signal are separated from high level excite signals by locating sensitive signals on the first board and excite signals on the second board.

Abstract: A method and apparatus for monitoring a door or a window is disclosed. In one embodiment, a method is described, comprising receiving, by a processor, an electronic signal from a motion sensor in response to movement of the door or window, determining a direction of movement of the door or window from the electronic signal by the processor, comparing the direction of movement to a predetermined direction by the processor, detecting, by the processor, an alarm condition of the door or window if the electronic signal indicates that the door or window is being opened, and transmitting, by a transmitter coupled to the processor, an alarm signal when the alarm condition has been detected.

Abstract: An integrated fluxgate device, which includes a magnetic core, an excitation coil, and a sense coil. The magnetic core has a longitudinal edge and a terminal edge. The excitation coil coils around the longitudinal edge of the magnetic core, and the excitation coil has a first number of excitation coil members within a proximity of the terminal edge. The sense coil coils around the longitudinal edge of the magnetic core, and the sense coil has a second number of sense coil members within the proximity of the terminal edge. For reducing fluxgate noise, the second number of sense coil members may be less than the first number of excitation coil members within the proximity of the terminal edge.

Abstract: In one embodiment, an inductive/LC sensor device includes: an energy storage device for accumulating excitation energy, an LC sensor configured to oscillate using energy accumulated in the energy storage device and transferred to the LC sensor, an energy detector for detecting the energy accumulated in the energy storage device reaching a charge threshold, and at least one switch coupled with the energy detector for terminating accumulating excitation energy in the energy storage device when the charge threshold is detected having been reached by the energy detector.

Abstract: The invention relates to a safety system (1) for a separating protective device with a first monitoring device for monitoring whether the separating protective device is bolted with a bolting system and with a second monitoring device for registering the position of the separating protective device. The second monitoring device has a sensor that generates direction-dependent signals and that differs from the first monitoring device.

Abstract: The present disclosure relates to sensor devices and the teachings may be applied to a sensor for determining a displacement of a shaft along its longitudinal axis. In some embodiments, a sensor device may include a sensor unit and a detection element. The sensor element is disposed at a fixed radial distance from the longitudinal axis. The detection element is arranged between the shaft and the sensor unit and coupled to the shaft. The side of the detection element facing away from the axis comprises a convex shape. A gap distance defined between the detection element and the sensor unit varies over an extent of the sensor unit perpendicularly with respect to the longitudinal axis and independently of a tilting angle of the shaft. The sensor unit generates a shaft displacement signal dependent on a displacement of the detection element in relation to the sensor unit along the longitudinal axis.

Abstract: A device for detecting the axial position of a rotor shaft of a rotary machine having a stator and a rotor is provided. The detecting device includes a sensor stator ring, secured to the stator, made from ferromagnetic material, facing the shoulder of one end of the hollow or not hollow rotor shaft and arranged so as to leave an axial airgap with the one end of the rotor shaft. The sensor stator ring having at least one annular slot receiving an annular induction coil. The rotor shaft is made from solid magnetic steel, an outer end of the rotor shaft acts as a target surface whose axial position is to be measured by the sensor stator ring.

Abstract: A variable inductor of which variable inductance characteristics can be adjusted is provided. The inductor includes: a magnetic core having a preset shape; and a coil part surrounding a portion of the magnetic core and generating a magnetic flux depending on a current flow, wherein the magnetic core includes a first magnetic region formed of a first magnetic material and a second magnetic region formed of a second magnetic material different from the first magnetic material.

Abstract: A method of measuring the thickness of a coating layer of a workpiece, the layer being formed on a substrate of the workpiece. The method comprises several steps. First, feeding a probe alternating electrical signal to induction device in order to induce a magnetic field in the workpiece. Second, measuring at least one physical characteristic that varies as a function of the magnetic field induced in the workpiece. Third, determining first and second values of an indicator, the values being determined respectively from measurements of the physical characteristic taken when the electrical signal has first and second given frequencies. Forth, calculating the difference between the first and second values of the indicator and determining the thickness of the coating layer as a function of the difference and of predetermined data correlating: the difference between the values of the indicator; and corresponding values for thicknesses of the coating layer.

Abstract: A circuit arrangement (1) for controlling an inductive displacement measurement sensor (2) is described. The displacement measurement sensor has a sensor coil (2), which is supplemented by means of a capacitor (Cpar) to form an oscillating circuit. In addition, the circuit arrangement has an oscillator (3) for generating an excitation signal (UExciter), which excites the oscillating circuit to oscillate. The excitation signal (UExciter) is superimposed with a DC voltage (Utemp), the amplitude of which changes when the temperature of the sensor coil (2) changes. The sensor coil (2) is connected to a controllable resistor (Rvar). Furthermore, the circuit arrangement (1) has a comparator (4), which compares the DC voltage (Utemp) with a reference voltage (Utref). On the basis of the result of the comparison, the comparator (4) outputs a control voltage (Ur), which controls the controllable resistor (Rvar).

Abstract: An improved sensor apparatus for developing a signal related to an inductive sensor in a resonant circuit are disclosed. This improvement is realized by adding a known capacitance to the resonant circuit and comparing the resulting natural resonance frequency to the frequency without the known capacitance. In this way a measure of the resonant capacitance is developed to correct the sensor signal for the effect of any changes in that capacitance. One disclosed embodiment adds an electronically variable capacitance which is adjusted to yield a constant capacitance that produces a sensor signal insensitive to variations in the resonant circuit capacitance. The resonant capacitance measurement may also provide an indication of another sensor state, such as temperature or pressure, which may be used to further correct for temperature or pressure sensitivities in the sensor signal. The invention is extended by juxtaposing the inductance for capacitance in the sensor resonant circuit.

Abstract: A sine wave oscillator for an inductive sensor system is disclosed. The sine wave oscillator comprises a decoupler and a low-pass filter, wherein the decoupler is configured to provide a pulse width modulated signal as a decoupled signal at one output of the decoupler. One input of the low-pass filter is connected to the output of the decoupler. The low-pass filter is configured to provide a sinusoidal signal for the inductive sensor system by using the inverted signal at an output of the low-pass filter. The sine wave oscillator further comprises a microcontroller that is designed to provide the pulse width modulated signal with a predetermined frequency and a predetermined duty cycle at one pin of the microcontroller.

Abstract: A foreign matter detection device including a detection coil between a power transmitting coil and a power receiving coil, and a detection unit detecting an induced voltage V generated in the detection coil and detects, from this induced voltage, presence or absence of a conductive foreign matter between the power transmitting coil and the power receiving coil. The detection coil includes a continuous conductive wire where two loop portions are wound in mutually opposite directions. An area or a winding number of each loop portion or a direction connecting centroids of the two loop portions is set so that the induced voltage (i.e., a reference voltage) generated in the detection coil when no conductive foreign matters exist becomes 0 or a minimum.

Abstract: A stroke sensor system includes a vehicle-body-side member, a wheel-side member, and a movement-amount deriving section. The movement-amount deriving section derives a movement amount of relative movement between the vehicle-body-side member and the wheel-side member. At least a part of one of the vehicle-body-side member and the wheel-side member is a conductor, and the other is provided with a coil. The movement-amount deriving section includes an even number of capacitors and an even number of exciting sections. The even number of capacitors are electrically coupled to the coil and configure an LC resonance section. The even number of exciting sections are for exciting an oscillation waveform output by the LC resonance section. The even number of capacitors and the even number of exciting sections are divided into equal numbers to configure a balanced circuit. The movement-amount deriving section derives the movement amount based on the oscillation waveform.

Abstract: A mobile device and a control method thereof are provided. The mobile device including a detecting module (1), a determining module (2), a controlling module (3) and a storing module (4).

Abstract: The present invention relates to a contactor, a connector and a contactor component. According to the first aspect of the invention, a contactor relates to a switch mechanism, an iron core, an iron core position sensing circuit and a control circuit. The control circuit can measure the position of the iron core by measuring the variation in inductance by using the property that the coil can produce different inductances when the iron core is in different positions in the coil. According to the second aspect of the invention, a connector and contactor component are provided, wherein a control circuit is arranged on a connector, the control circuit comprises a PWM power-saving circuit. The PWM power-saving circuit is integrated on the connector, so that the average driving current of the contactor is reduced and meanwhile, the size of the contactor is reduced.

Abstract: A magnetic sensing device including a U-shaped magnet with a pair of legs and a base defining a first interior channel and a distal plane. A sensor assembly in the first interior channel includes a sensor that extends above the distal plane. The magnet generates a first region of low or no flux above the distal plane in a first position of the magnet, a second region of low or no magnetic flux in the interior channel in a second position of the magnet, and a third region of magnetic flux above the distal plane in the second position of the magnet which causes the sensor to activate a control signal. The base includes steps and a second interior channel that opens into the first interior channel.

Abstract: The present invention relates to a non-contact potentiometer.

Abstract: An apparatus for testing an impedance range of a wireless power transmitter is provided. The apparatus comprises an adjustable impedance circuit configurable to be connected to a power source. The apparatus further comprises a transformer coupled the adjustable impedance circuit. The apparatus further comprises a sensing circuit configured to sense a parameter indicative of a parasitic impedance of the adjustable impedance circuit. The apparatus further comprises a driver circuit configured to drive the transformer with a signal based on the sensed parameter that causes the transformer to apply a first voltage to the adjustable impedance circuit. The first voltage has a substantially same amplitude as a voltage drop caused by the parasitic impedance. The second voltage is out of phase with the voltage drop. The sensed parameter is a current circulating in the adjustable impedance circuit or a voltage across at least a portion of the adjustable impedance circuit.

Abstract: A piston-cylinder assembly, in particular for pneumatic, hydraulic or mechatronic systems, includes a cylinder housing and a piston. The piston is coupled to a piston rod and disposed in the cylinder housing such that it can move along a longitudinal axis. A measuring device for detecting piston or piston rod position is provided inside the cylinder housing.

Abstract: An electrically driven motor includes a motor rotor having a rotor core and a plurality of permanent magnets attached onto an outer circumferential portion of the rotor core. The electrically driven motor also includes a stator having a plurality of slots. In the electrically driven motor, a plurality of projections rotor teeth are disposed at positions of the outer circumferential portion of the rotor core which are spaced apart from each other by a predetermined interval of distance and which include a magnetic pole center of at least one permanent magnet. The plurality of rotor teeth extend all the way to a location of the teeth of the stator.

Abstract: A high sensitivity inductive sensor for measuring clearance of a rotating blade tip includes a one or more of sensing coils. The sensing coils are formed of magnet wire, which is wound to form planar spiral coils. Each of the coils are coupled in series with a function generator, which applies an excitation signal thereto. Accordingly, based on the change in impedance of the coils, a clearance measurement, which identifies the distance between the coil and the tip of the rotating blade can be obtained using predetermined calibration curve values.

Abstract: A vessel (1) includes a spud (10), a spud lifting device (20) and a plurality of spud guiders (30). The spud guiders (30) are arranged to hold the spud (10) in a substantial vertical orientation and guide the spud (10) when moving in a substantial vertical direction between a lower position in which it can engage with a water bottom and an upper position. The spud lifting device (20) is arranged to lift the spud (10) from the lower position to the upper position. The vessel (1) further includes a spud position detector (40) to detect passage of the lower end (11) of the spud (10) along one or more spud detection points at predetermined heights.

Abstract: The disclosure relates to systems, methods and apparatus for analyzing an infrastructure system including measurement of a parameter associated with the infrastructure system, electronically recording the measured parameter as a data, transferring the data to an infrastructure unit which may be remote from the infrastructure system, analyzing the data to generate a risk model, and predicting a characteristic of the infrastructure system according to the risk. An implementation plan may be generated, and/or maintenance services may be performed as per the characteristic that is predicted.

Abstract: Method, device and system for measuring a degree of torsion or bending of a joint. The method comprises the steps of attaching a sensor (56) to the limbs that are joined by the joint, measuring an output signal of the sensor during torsion or bending at the joint, and a final step of relating said output signal of the sensor to a degree of torsion or bending. The sensor comprises an electrically conductive loop (51), with loop parts that run from one limb to other and back in the loop, the area of said loop at least partially covering both limbs from one limb to the other. The limbs may be limbs of the human or animal body, for instance limbs at a knee. The sensor further comprises an output unit (57) for providing an output signal that is a measure for the inductance of the loop. Calibration data for the sensor may be determined by detecting the output signal of the sensor for a well defined degree of torsion or bending at said joint under static conditions and storing the calibration data.

Abstract: A testing assembly for testing a magnetic sensor comprises a testing interface and a detachable magnetic-field generator. The testing interface has a base plate and plurality of testing terminals. The base plate has a first side and a second side opposite to the first side. The plurality of testing terminals is arranged on the first side of the base plate. The detachable magnetic-field generator is arranged on the second side of the base plate in a detachable fashion. The detachable magnetic-field generator has a coil support and at least one coil winding around the coil support.

Abstract: A metal detection device includes a metal detection coil arranged in a metal detection area, wherein the metal detection coil is excited, and an electromagnetic wave radiated from the metal detection coil detects whether metal exists in the metal detection area. An oscillation circuit generates a sinusoidal oscillating current having a single fundamental frequency and supplies the oscillating current to the metal detection coil to excite the coil. A harmonic level detection circuit detects a harmonic component of the fundamental frequency component of the oscillating current and generates a detection signal. A comparison circuit compares a signal level of the detection signal and a pre-set reference value. A processing circuit determines whether metal exists in the metal detection area based on a comparison result. When determining that metal exists in the metal detection area, the processing circuit drives a notification unit to issue a notification indicating detection of metal.