8847 results about "Current sensor" patented technology

A powered surgical stapler is disclosed. The stapler includes a housing, an endoscopic portion extending distally from the housing and defining a first longitudinal axis, a drive motor disposed at least partially within a housing and a firing rod disposed in mechanical cooperation with the drive motor. The firing rod is rotatable by the motor about the first longitudinal axis extending therethrough. The stapler also includes an end effector disposed adjacent a distal portion of the endoscopic portion. The end effector is in mechanical cooperation with the firing rod to fire a surgical fastener. The stapler further includes a current sensor configured to measure a current draw on the motor and a controller configured to determine whether the surgical fastener is successfully deployed based on the current draw on the motor.

A system for efficient delivery of radio frequency (RF) energy to cardiac tissue with an ablation catheter used in catheter ablation, with new concepts regarding the interaction between RF energy and biological tissue. In addition, new insights into methods for coagulum reduction during RF ablation will be presented, and a quantitative model for ascertaining the propensity for coagulum formation during RF ablation will be introduced. Effective practical techniques a represented for multichannel simultaneous RF energy delivery with real-time calculation of the Coagulum Index, which estimates the probability of coagulum formation. This information is used in a feedback and control algorithm which effectively reduces the probability of coagulum formation during ablation. For each ablation channel, electrical coupling delivers an RF electrical current through an ablation electrode of the ablation catheter and a temperature sensor is positioned relative to the ablation electrode for measuring the temperature of cardiac tissue in contact with the ablation electrode. A current sensor is provided within each channel circuitry for measuring the current delivered through said electrical coupling and an information processor and RF output controller coupled to said temperature sensor and said current sensor for estimating the likelihood of coagulum formation. When this functionality is propagated simultaneously through multiple ablation channels, the resulting linear or curvilinear lesion is deeper with less gaps. Hence, the clinical result is improved due to improved lesion integrity.

An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). An exemplary apparatus comprises: a plurality of LEDs coupled in series to form a first plurality of segments of LEDs; a plurality of switches coupled to the plurality of segments of LEDs to switch a selected segment into or out of a series LED current path in response to a control signal; a current sensor; and a controller which, in response to a first parameter and during a first part of an AC voltage interval, generates a first control signal to switch a corresponding segment of LEDs into the series LED current path; and during a second part of the AC voltage interval, generates a second control signal to switch a corresponding segment of LEDs out of the first series LED current path.

A method and apparatus for switching AC appliances and lights of residences and other automation systems through SPDT or DPDT relays connected in electrical circuit with SPDT or DPDT switch including a current sensor and/or a status sensor. The operating key of the relay and the key lever of the electric switch can each be used for operating a dedicated appliance or light, a group of appliance and lights and all appliance and/or lights including scenarios setup via the many well known two way, three way or four way light switches, by operating the switch lever or key in multi steps. The SPDT or DPDT relays are operated via RF, IR and fiber optic communicating two way signal for operating the lights and reporting statuses.

Apparatus and method for stimulating neuromuscular tissue in the stomach. The neuromuscular stimulator stimulates the neuromuscular tissue by applying current-controlled electrical pulses. A voltage sensor detects the voltage across the neuromuscular tissue to determine if the voltage meets a predetermined voltage threshold. A control circuit adjusts the current-controlled pulse if the voltage is found to meet the voltage threshold, such that the voltage does not exceed the voltage threshold. A voltage-controlled pulse may also be applied to the tissue. A current sensor would then detect whether the current on the neuromuscular tissue meets a predetermined current threshold, and a control circuit adjusts the voltage controlled pulse such that the current does not exceed the current threshold. A real time clock may be provided which supplies data corresponding to the time of day during the treatment period. A programmable calendar stores parameters of the stimulating pulse, wherein the parameters have a reference to the time of day.

A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

An LDO voltage regulator includes an error amplifier having a first input coupled to a first reference voltage, a second input receiving a feedback signal, and an output producing a first control signal. An output transistor has a gate, a drain coupled to an unregulated input voltage, and a source coupled to produce a regulated output voltage on an output conductor. A feedback circuit is coupled between the output conductor and a second reference voltage. An overvoltage comparator has a first input coupled to receive the first reference voltage and a second input coupled to respond to the feedback signal to produce a discharge control signal indicating occurrence of an output overvoltage of at least a predetermined magnitude to control a discharge transistor coupled between the output conductor and the second reference voltage. An output current sensing circuit produces a control current representative of the drain current of the output transistor. An offset capacitor is coupled between the output of the error amplifier and the gate of the output transistor, and a servo amplifier has a first input coupled to receive a third reference voltage, a second input coupled to the output of the error amplifier, and an output coupled to the gate of the output transistor to produce a second control signal thereon. A current sensor circuit, a current capacitor, and an AND circuit operate to allow the discharge transistor to be turned on only if the output current is below a certain level.

An integrated sensor includes a magnetoresistance element electrically coupled to a device disposed on or integrated in a silicon substrate. A conductor is provided proximate to the magnetoresistance element. The integrated sensor can be used to provide various devices, such as a current sensor, a magnetic field sensor, or an isolator. Further, the integrated sensor can be used in an open loop configuration or in a closed loop configuration in which an additional conductor is provided. The magntoresistance element may be formed over the silicon substrate or on a separate, non-silicon substrate. Also described is an integrated sensor comprising a substrate, a magnetic field transducer disposed over a surface of the substrate, and a conductor disposed over the surface of the substrate proximate to the magnetic field transducer. The magnetic field transducer can be a Hall effect transducer or a magnetoresistance element.

An inverter is provided, which includes: a voltage converter that converts a DC voltage from an external device into an AC voltage to drive at least a lamp and includes a primary coil and first and second secondary coils connected in series; a current sensor that senses at least a current flowing in the first or second secondary coil and generate at least a sensing signal based on the sensed at least a current; a feedback signal generator that generates a feedback signal based on the at least a sensing signal from the current sensor; and a controller that controls the voltage converter based on the feedback signal such that a tube current flowing in the at least a lamp keeps substantially constant.

Non-invasive, optical apparatus and methods for the direct measurement of hemoglobin derivatives and other analyte concentration levels in blood using diffuse reflection and transmission spectroscopy in the wavelength region 400-1350 nm which includes the transparent tissue window from approximately 610 to 1311 nanometers and, using diffuse reflection spectroscopy, the mid-infrared region from 4.3-12 microns in wavelength. Large area light collection techniques are utilized to provide a much larger pulsate signal than can be obtain with current sensor technology. Sensors used in separate or simultaneous precision measurements of both diffuse reflection and transmission, either separately or simultaneously, from pulsate, blood-perfused tissue for the subsequent determination of the blood analytes concentrations such as arterial blood oxygen saturation (SaO₂), carboxyhemoglobin (COHb), oxyhemoglobin (OHb), deoxyhemoglobin (dOHb), methemoglobin (metHb), water (H2O), hematocrit (HCT), glucose, cholesterol and proteins such as albumin and other analytes components.

The present invention provides a multitude of embodiments for landscape water conservation with automated water budgeting or seasonal adjustment. Water budget automation may be implemented within an irrigation controller, by means of an add-on or a plug-in to the controller, or broadcast from a central location. The environmental data used for automated water budgeting may be historical including ambient temperature, wind, solar radiation, relative humidity, soil moisture, soil temperature, or evapotranspiration, or combinations thereof, or with a combination of current sensor data. The automated water budgeting may be accomplished with a percentage accumulation method which adjusts watering intervals and schedules, or on a daily percentage basis. In addition, government based restricted watering schedules may be combined within all the above embodiments to provide additional flexibility for water conservation.

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.

A direct current feeder protection system includes six conductors, four current sensors sensing four currents flowing in four of the conductors, four circuit interrupters interrupting currents flowing in the four conductors, and a processor cooperating with the current sensors to input four sensed currents, and to output a number of commands to the circuit interrupters. The processor includes a routine detecting a number of: a directional current fault of the sensed currents, a differential current fault of the sensed first and third currents or the sensed second and fourth currents, and a residual current fault of the sensed first and second currents or the sensed third and fourth currents, and to responsively output the commands. The first, fifth and third conductors are electrically connected in series with two of the circuit interrupters, and the second, sixth and fourth conductors are electrically connected in series with the other circuit interrupters.

A controller for controlling a light emitting diode (LED) light engine. The controller includes a temperature sensor configured to sensor temperature at the LED light engine. A current sensor senses a drive current of the LED light engine. A voltage differential sensor senses a voltage differential across LEDs of the LED light engine. A timer monitors a time of operation of the LED light engine. Further, a control device controls the drive current to the LED light engine based on the sensed temperature, the sensed drive current, the sensed voltage differential, and the monitored time of operation. Further, the control device outputs an indication of intensity degradation of an LED, and if the intensity degradation exceeds a predetermined threshold the control can output an indication of such to a user, so that the user can be apprised that the LED needs to be changed.

A wireless interface remote monitoring system for self-propelled irrigation systems (center pivot and lateral move sprinklers) includes a remote terminal unit (RTU) mounted on an outer drive tower of the irrigation system. The RTU includes a radio transceiver capable of sending and receiving data packets over a satellite or terrestrial telemetry backbone to and from a central control computer. The RTU further includes a current sensor and a GPS receiver both for detecting movement or non-movement of the sprinkler, a microprocessor with nonvolatile memory for storing current data and GPS coordinate data from readings taken in series over time, and a pressure or flow sensor for detecting the presence or absence of water flow at the outer drive tower of the sprinkler. The current sensor connected between the RTU and a tower drive motor, allows the RTU to calculate the “movement” or “non-movement” of the irrigation system over a specified time period. Redundantly, the GPS receiver records changes in position to indicate movement or non-movement within the GPS error tolerance. Once a change from movement to non-movement or vice-versa is determined, the RTU transmits the data by satellite or radio telemetry to a central control computer which logs the movement or non-movement of the monitored drive tower, the GPS coordinate data and the water status readings, all with time and date stamp. The central control computer creates “page message” and “text message” updates as necessary on the status of individual irrigation systems and “groups” of irrigation systems that are in turn delivered to wireless devices and computers for sprinkler operators.

A motor control device capable of suitably inhibiting the pulsating torque of an alternating-current motor is provided. The motor control device comprises an axis error inference machine (30) which infers an axis error based on a current value of an inverter, detected by a current sensor (2); a Fourier rectification machine (316a) which extracts an axis error vector from the time-base changes of the axis error; an integral control machine (316b) additionally provided with a circular amplitude limiter, which is used to calculate a correction current vector for offsetting the pulsating torque, wherein a circle with a set amplitude limiting value serving as the radius is used as the base for limiting the movement of the correction current vector, and the integral control machine (316b) additionally provided with the circular amplitude limiter performs the circular amplitude limiting for limiting the movement of the correction current vector so as to enable the deflection angle of the correction current vector to be close to the deflection angle of the axis error vector.

An integrated current sensor includes a magnetic field transducer such as a Hall effect sensor, a magnetic core, and an electrical conductor. The conductor includes features for receiving portions of the Hall effect sensor and the core and the elements are dimensioned such that little or no relative movement among the elements is possible.

An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and substrate having a first surface in which is disposed one or more magnetic field transducers, with the first surface being proximate the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit relative to a conventional orientation. With this arrangement, a current sensor is provided for which the one or more magnetic field transducers are very close to the current conductor portion, resulting in a current sensor having improved sensitivity.

An apparatus, method and system are provided for controlling the solid state lighting, such as LEDs. An exemplary apparatus comprises: a switch for switching electrical current through the LEDs, a current sensor; a first comparator adapted to determine when a switch electrical current has reached a first predetermined threshold; a second comparator adapted to determine when the switch electrical current has reached a predetermined average current level; and a controller. The controller is adapted to turn the switch into an on state and an off state, to determine a first on time period as a duration between either a detection of a second predetermined current threshold or the turning the switch into the on state, and the detection of the predetermined average current level; to determine a second on time period as a duration between the detection of the predetermined average current level and the detection of the first predetermined current threshold; and to determine an on time period of the switch as substantially proportional to a sum of the first on time period and the second on time period. Additional exemplary embodiments utilize a difference between the first and second on time periods to generate an error signal to adjust the on time period of the switch.

A disk drive is disclosed comprising a spindle motor for rotating a disk, wherein the current applied to the spindle motor is controlled by adjusting a duty cycle of a pulse width modulated (PWM) signal. A current sensor generates a current sense signal representing a current flowing from a supply voltage. The current sense signal is integrated to generate an integration signal. The integration signal is compared to a threshold, and the result of the comparison is used to adjust the duty cycle of the PWM signal. In this manner the disk drive draws essentially constant average input current from the supply voltage which decreases the spin up time of the disk.

An integrated circuit current sensor includes a lead frame having at least two leads coupled to provide a current conductor portion, and a substrate having a first surface in which is disposed one or more magnetic field sensing elements, with the first surface being proximate to the current conductor portion and a second surface distal from the current conductor portion. In one particular embodiment, the substrate is disposed having the first surface of the substrate above the current conductor portion and the second surface of the substrate above the first surface. In this particular embodiment, the substrate is oriented upside-down in the integrated circuit in a flip-chap arrangement. The current sensor can also include an electromagnetic shield disposed between the current conductor portion and the magnetic field sensing elements.