Inductive sensor

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

Circuit arrangement for evaluating the signals of an inductive sensor

Abstract: The invention is directed to a circuit arrangement for evaluating the signals of an inductive sensor such as the kind utilized on internal combustion engines. The coil of the inductive sensor is connected via a coupling capacitor to a differential amplifier connected in the form of a comparator. The coil of the sensor is also connected via the coupling capacitor to a resistance for equalizing charge as well as to a peak-value detector. The peak-value detector is connected to the input of the comparator either directly or via an amplifier circuit and effects a threshold adjustment for the comparator which occurs in dependence upon the signal supplied by the inductive sensor and in dependence upon the rotational speed. Manufacturing variations of the inductive sensor as well as temperature changes have no influence on the output signal.

Alarm system for detecting hazards due to power transmission lines

Abstract: An alarm system for detecting and warning of the risk of shock and electrocution is provided. The alarm system is adapted for use with mobile construction equipment, e.g., cranes, trucks, etc., that can be used around overhead power transmission lines. The present alarm system has a sensor that detects the presence of outside power at the equipment where current is flowing therethrough to ground. The sensor preferably includes a conductor and an inductive sensor such as a current transformer which limits the output signal on its low side that is sent to an alarm unit. In this manner, the system herein continues to properly function despite the presence of large voltages at the equipment such as when the equipment contacts a high voltage power transmission line. The sensor can include a cable that provides a path of least resistance for current flowing through the equipment which can be detected by the sensor. Preferably, the cable is attached across a moving joint of the equipment where potential differences readily can be found. Alternatively, the conductor can be a portion of the equipment itself through which current flows with the sensor detecting the flow through the equipment portion.

Wireless current sensing by near field induction from a spin transfer torque nano-oscillator

Abstract: We demonstrate that spin transfer torque nano-oscillators (STNO) can act as wireless sensors for local current. The STNO acts as a transducer that converts weak direct currents into microwave field oscillations that we detect using an inductive coil. We detect direct currents in the range of 300–700 μA and report them wirelessly to a receiving induction coil at distances exceeding 6.5 mm. This current sensor could find application in chemical and biological sensing and industrial inspection.

Intrusion alarm apparatus

Abstract: An intrusion detection apparatus employing two or more diverse types of sensors for sensing entries into a room, building or other enclosure. The sensors are connected to a signal processor which processes sensor output signals to indicate when an intrusion has occured. One type of sensor is a local sensor which includes a sensor conductor in combination with a phase locked loop. Whenever an intruding object is within close proximity to the sensor conductor and disturbs the conductor field, the equilibrium condition of the phase locked loop is disturbed to provide a sensor output signal. A second type of sensor includes in one embodiment an omni-directional antenna having a field which is located in close proximity to or which is overlapping the field of the sensor conductor. Whenever the omni-directional antenna and the sensor conductor are disturbed, the two disturbances are detected by the signal processor to signal an intrusion if the proper time relationship exists between them.

A highly sensitive dual mode tactile and proximity sensor using Carbon Microcoils for robotic applications

Abstract: This paper presents a highly sensitive dual mode tactile and proximity sensor for robotic applications that uses Carbon Microcoils (CMCs) The sensor consists of multiple electrode layers printed on a Flexible Printed Circuit Board (FPCB) and a dielectric substrate into which the CMCs are dispersed The dielectric layer is simply put on the top of the FPCB Thus, the sensor provides ease of fabrication and robustness against repetitive external contacts because the dielectric layer protects the electrodes The electrical properties of the sensor are changed when an object approaches or touches the sensor The sensor uses a capacitive sensing mode for tactile sensing and an inductive sensing mode for proximity sensing CMCs amplify the change of the sensor signal because of electrical impedance formed by the CMCs, and thus, the sensitivity of the sensor increases We fabricate the prptotype sensor with the dimensions of 30 × 30 × 06 mm3, and with 3 mm spatial-resolution The sensor detects the applied pressure up to 330 kPa and the distance of an object as much as 150 mm away