Inductive sensor

About: Inductive sensor is a research topic. Over the lifetime, 2282 publications have been published within this topic receiving 21984 citations.

Means for reducing minimum sensing distance of an ultrasonic proximity sensor

Abstract: A rugged ultrasonic sensor is provided which is capable of detecting objects in very close proximity to the sensor. This close proximity detection includes the detection of objects which are immediately adjacent the sensor housing. Such close range operation is achieved by tailoring the transducer to operate at previously undesirable conditions, including low Q and high frequency. Such operating conditions allow the resonating characteristics of the transducer not to interfere with close range operation.

Planar inductive sensor for small displacement

Abstract: This paper presents a meander type displacement inductive sensor, developed in printed circuit board (PCB) technology. It also describes design, realization and the input inductance measurement of sensor. The displacement in two directions (less than 0.5 mm) can be detected by using two sensor's elements (i.e. two pairs of meander coils). In each pair, one of the coils is fixed, and between its terminals the input inductance was measured, while other coil is short-circuited. If one coil is moved above the other in directions of x- and z-axes, coupling between coils will change, as well as input inductance, which serves as a measure of displacement. In order to achieve better linearity of the sensor, gap is inserted in the middle of each conductive segment of fixed coils. Four sets of inductive sensors were realized: without gap and with three different gaps: 0.25 mm, 0.51 mm and 0.76 mm. In addition, a simple model of the inductive sensor is proposed. Using this model, the input inductance of displacement sensor was calculated and compared with measured values. A good agreement was found.

Method for e.g. determining degree of wear i.e. blunting, of rotary blade in field chopper in agricultural field, involves determining reduction of width of blade back side and distance from blade to counter blade from parameters of curve

Abstract: The method involves transmitting sensor values to an evaluation unit during transit of a blade through a measuring field (4) of an analog inductive sensor (3). Signals e.g. voltage signal and current signal, of the inductive sensor are converted into a curve i.e. u-shaped voltage-time-curve. Reduction of width of blade back side and distance from a blade (11) to a counter blade (2) are determined from two characterizing parameters e.g. sensor voltage, of the curve. Sharpness of the blade is determined from the characterizing parameters of transit time and change of minimum voltage. An independent claim is also included for a device for determining degree of wear of a rotary blade and/or change of distance from the blade to a counter blade of a straw cutter.

Integrated inductive sensors for the detection of magnetic microparticles

Abstract: In this paper, we deal with novel inductive microsensors, realized by using standard CMOS microelectronic technologies, for the detection of small amounts of magnetic beads that are placed in selected regions over the surface of the microsensor. The sensor proposed here represents a step toward the development of integrated inductive biosensors for application in the area of magnetic immunoassay where magnetic markers, carrying specific antibodies that selectively bind to the cells or molecules to be detected, are used; the measurement of the analyte concentration is therefore accomplished by determining the concentration of magnetic particles tied to it. A planar differential transformer structure is proposed here as part of the measurement strategy. The analysis, simulation, and design of the proposed device are reported, and its sensitivity to the quantity of micromagnetic beads deposited over its surface has been also demonstrated through experiments.

Device for measuring rotational and translatory movements

Abstract: The device has a rotatable sensing wheel (1) attached to a magnetic pole (2), which transmits a signal. A sensor (3) detects the signal transmitted by the pole (2) for detecting rotational angle and/or angular speed of the wheel, where the sensor is formed as hall sensor, difference hall sensor, magneto-resistance sensor, giant magneto-resistance sensor or inductive sensor. Another two magnetic poles (4, 5) detect a translatory movement, which is superimposed on a rotating movement of the wheel, where the poles (2, 4, 5) are arranged at an outer circumference of the wheel.