Inductive sensor

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

A novel approach of using a planar inductive position sensor for the Permanent magnet synchronous motor control application

Abstract: Permanent magnet synchronous motors (PMSM) are taking over the commercial, industrial (robotics) and automotive industry. Most of the applications demand high starting torque at zero speed. For generating the desired amount of torque at zero speed, accurate rotor position information is necessary, which is obtained by using position sensors. Hall sensors with digital output are sensitive to temperature and external magnetic fields and do not offer high resolution. Optical encoders provide good resolution but lead to higher cost and reliability related issues in the harsh/contaminated environment. Inductive sensing technology is an emerging technology which can be used in wide range of application such as proximity, angular displacement, linear displacement etc. PMSM control is one such application that can make use of planar Inductive position sensors which are contactless sensors, works on LVDT principle. These can be inexpensively built with stationary printed circuit board PCB coils and metal target. Inductive sensors are absolute devices which mean that they need no motion at power up to determine position. This paper covers planar inductive position sensor and its usage in PMSM control application. The experiments are carried out to substantiate the proposed technique in the speed controlled drive system of PMSM.

Mobile terminal with fingerprint sensor packaging structure

Abstract: The invention discloses a mobile terminal with a fingerprint sensor packaging structure. A capacitive semiconductor fingerprint sensor COG (Chip On Glass) packaging technology is adopted. The mobile terminal comprises a case, a display screen, a touch screen cover plate and a semiconductor capacitive fingerprint sensor. A touch screen module comprises the touch cover plate and a touch inductive sensor film. The touch screen cover plate covers the semiconductor capacitive fingerprint sensor through an anisotropic conductive film. Therefore, the semiconductor capacitive fingerprint sensor is arranged below the non-display area of the touch screen so as to achieve the objective of hiding the fingerprint sensor. The fingerprint sensor has extremely high detection sensitivity and can acquire a fingerprint image through the touch screen cover plate of a few hundred microns. Besides, the manufacturing technology of the standard COG packaging technology is adopted with no requirement for more modification of the touch screen production technology so that processing difficulty is reduced and efficiency is enhanced, and satisfaction of users in using the fingerprint identification sensor is enhanced.

Device for sensing the displacement of moving members in industrial equipment

Abstract: A device for sensing the displacement of working members in industrial equipment is disclosed. The above sensing device includes cheap analog inductive sensors capable of maintaining the sensing characteristics irrespective of moisture and leaking water, thereby precisely sensing the displacements of the working members. The sensor housing of the device easily fixes the analog inductive sensor by simply fitting the sensor into a mount hole formed in the housing, thereby easily changing the troubled sensor with a new one and easily focusing the sensor when initially mounting the sensor to the housing. As a pair of analog inductive sensors are mounted to both side surfaces of the working member, the sensing device of this invention also prevents the operational errors to the sensors caused by the operational vibrations of the working members while sensing the displacements of the working members.

Optimized magnetic sensors to measure speed and position in adverse environments

Abstract: The paper reviews features and applications of the modified inductive sensor, able to operate in contact with exhaust gases of temperature even as high as 1200 K. The new design includes the metal-ceramic housing ensuring proper heat transfer, the magnetic circuit containing set of permanent magnets with various magnetic field values and Curie temperatures, the completely redesigned windings and current/voltage converter used instead of the electromotive force amplifier. Its principle of operation is based on electrodynamical interaction and therefore it may be referred as a passive eddy-current sensor. Two applications of the technique are presented such as blade vibration measurement in High Pressure Turbine of military turbofan (tip-timing) and speed monitoring of roller-element bearing supporting the shaft in a turbojet engine.

Method, devices and systems for detecting an attachment of an electronic patch

Abstract: An electronic sensor patch includes a capacitive sensor configured to detect when the electronic sensor patch is applied to a patient. A processor may be powered down for a predetermined time interval in response to determining that the electronic patch is not in close proximity to a body. The electronic sensor patch may be activated in response to determining that the electronic patch is in close proximity to the body. The capacitance sensor may be used to determine whether the electronic sensor patch is in close proximity to a body by measuring capacitance of the capacitance sensor, comparing the measured capacitance to a threshold, and determining that the electronic sensor patch is in close proximity to a body in response to the measured capacitance of the capacitance sensor being more than the threshold.