Current sensor

About: Current sensor is a research topic. Over the lifetime, 18957 publications have been published within this topic receiving 147433 citations.

Power line communications device and method

Abstract: In one embodiment, a power line communication system network element is provided that provides communications to one or more user devices. The device may also receive data from one or more sensors, such as current sensors, a voltage sensor, a video camera, a temperature sensor, a barometer, a motion sensor, a level sensor, and/or a vibration sensor. The device may include a controller that receives commands that relate to the collection and transmission of the sensed data via a medium voltage power line.

Low power current-to-frequency converter circuit for use in implantable sensors

Abstract: A low power current-to-frequency converter circuit provides an output frequency signal FOUT having a frequency that varies as a function of a low level analog input current signal. The analog input current signal is typically generated by an implantable sensor element, designed to sense a particular substance or parameter within body tissue or fluids to which the sensor is exposed, with the magnitude of the analog signal providing a measure of the sensed substance or parameter. Conversion of the low level analog current to the output frequency signal facilitates transmission of the data signal over a shared data bus and other digital processing of the data signal. The current-to-frequency converter circuit is fabricated from low power FET-based integrated circuits, and includes an operational amplifier having its positive input terminal connected to a storage capacitor that is charged by the analog input current signal, a voltage-controlled oscillator driven by the charge (voltage) on the storage capacitor that produces the output frequency signal, and a charge pump circuit that pumps a discrete amount of charge off of the storage capacitor during each cycle of the output frequency signal.

Single current sensor technique in the DC-link of three-phase PWM-VS inverters. A review and the ultimate solution

Abstract: This paper proposes an ultimate solution for reconstruction of three phase-currents in a PWM-voltage source inverter by one current sensor in the DC-link, and it gives a review of existing methods in literature and patents. The solution offers fully protection of the inverter including shoot-through of the DC-link, short-circuit of the output phases and earth faults with both low and high impedance. A special configuration in the DC-link can give such features. At the same time a new method to sample the DC-link current is proposed which both can eliminate disturbances from cables between an inverter and an induction motor, and it offers a true simultaneous sample value of all three phase-currents in the center of a switching period. The two methods are implemented in an experimental setup, and test results show that full protection is achieved and the three phase-currents are reconstructed precisely in the whole operating area.

Battery monitor and method for providing operating parameters

Abstract: A battery monitor which monitors the operating parameters of a battery to provide an indication of, for example, the absolute state of charge, the relative state of charge, and the capacity of the battery under battery discharge, rest, and recharge conditions. The battery monitor includes a current sensor for sensing battery current, a voltage sensor for sensing battery voltage, and a temperature sensor for sensing battery temperature. A processor approximates to a high level of accuracy the battery parameters utilizing an iterative process based upon predetermined relationships, employing empirically determined constants and parameters determined in the immediately proceeding iteration stored in memory. Output signals indicative of the determined parameters are provided and may be utilized for many different battery applications.

Sensor devices for structural health monitoring

Abstract: Described herein are wireless interrogation systems and methods that rely on a complementary sensing device and interrogator. The sensing device is disposed to measure a parameter indicative of the health of a structure. A sensor reading from the sensor indicates the level of a parameter being monitored or whether one or more particular physical or chemical events have taken place. Using wireless techniques, the interrogator probes the device to determine its identity and its current sensor reading. This often includes transmission of a wireless signal through portions of the structure. When activated, the device responds with a wireless signal that identifies the device and contains information about the parameter being measured or a particular sensor state corresponding to the parameter. The identity of the device allows it to be distinguished from a number of similar devices. Thus this invention finds particular usefulness in the context of an array of devices that can be probed by a wireless interrogation unit. In one embodiment, the devices are passive and derive power from the interrogation signal.