Showing papers on "Bridge circuit published in 2002"

RFID tag with bridge circuit assembly and methods of use

Abstract: Radio frequency identification tag devices with bridge circuit assemblies and methods for high-volume, low-cost production are disclosed. The bridge circuit assemblies and methods of the present invention can reduce the complexity of the RFID tag devices by providing a one-sided circuit design. The resonant frequency of the circuits formed on the devices may be tuned by severing selected connections to one or more tuning capacitor plates that form a part of the capacitor structure. Severing connections to the tuning capacitor plates changes the capacitance of the circuit that, in turn, changes the resonant frequency of the circuit. Further, the devices and methods of the present invention allow for the option of placing a die either on the antenna substrate or on the bridge circuit assembly.

Current inverter for direct/alternating currents, has direct and alternating connections with an intermediate power store, a bridge circuit, rectifier diodes and a inductive choke

Abstract: Between two direct current (DC) connections in a parallel wiring structure there is a intermediate power store and a bridge circuit with two parallel branches (A/B,C/D), to each of which are wired rectifier diodes (DA,DB,DC,DD) in parallel. Certain rectifier diodes (DE,DF) link to each other in single connecting paths (9,10) in an opposed conducting direction. Each of two alternating current (AC) connections links individually via a connection node to one of the parallel branches between two switch units by means of a connecting wire, in which each has inductive chokes (L1,L2).

Occupant presence detection device

Abstract: The purpose of this invention is to sense the presence of a seated occupant in a vehicle such as an automobile, plane, train or bus or in a room or location where it is desirable to detect if seats are occupied. The occupant presence detection device consists of a single seat. mounted electrode, an oscillator circuit, a bridge circuit, a detection circuit and a circuit for processing the detected signals. The oscillator circuit excites the electrode . If an occupant is present on the seat, additional capacitance from the human body is introduced into the bridge via the electrode. This created differences in the voltage and phase of the waveform in each arm of the bridge circuit which are amplified by a differential amplifier. The signal is then converted to a DC voltage that, when above a predetermined threshold, causes the device to outputs a signal that indicates the presence of an occupant. Using a bridge configuration and a differential amplifier allows the circuit to be operated over a wide range of supply voltages. It also reduces the need for high precision components and the need to regulate the amplitude of the waveform produced by the oscillator. The net result is a capacitive occupant sensing device that is less complex and less expensive that previous capacitive occupant sensing devices, yet is tolerant of power supply fluctuations, is able to function over a wide range of operating voltage and still provides failsafe functionality.

Temperature information detecting device for angle sensor and position detecting device

Abstract: A temperature information detecting device for an angle sensor is provided for detecting only temperature-dependent components based on middle-point potentials when a constant current is supplied to a bridge circuit for an angle sensor, for acquiring a temperature of the angle sensor from the temperature-dependent components, for employing compensating information corresponding to the acquired temperature without separately providing any additional temperature sensor, and for making temperature compensation of the output of the temperature sensor in automatically controlling the valve opening of a flow control valve.

Apparatus and method for driving a high intensity discharge lamp

Abstract: An inverter circuit (1) that drives a lamp (LAMP), includes a buck filter network (L1 and C1), an ignition network including at least an ignition capacitive device (C2), a bridge circuit including at least one pair of switching devices (Q1 and Q4, Q2 and Q3), and a controller (CTLR) that controls an ON time and an OFF time of each switching devices (Q1-Q4) to effect a polarity transition of at least one of a lamp voltage and a lamp current. The controller (CTLR) controls a length of a dead time such that the dead time ends just before the polarity transition.

Switching power supply

Abstract: A switching power supply includes: a transformer including primary and secondary windings; a switching circuit including first and second switching elements, first and second rectifying elements, first and second capacitive elements and a first inductor; and a rectifying/smoothing circuit. A first bridge circuit is configured by the first and second switching elements located in a diagonal arrangement and the first and second capacitive elements also located in a diagonal arrangement. The first and second rectifying elements are connected in parallel to the first and second switching elements, respectively. One of the first and second rectifying elements is in forward direction and other is in inverse direction. The first inductor is disposed on a connection line between the pair of input terminals and the first bridge circuit. The primary winding is connected to the first bridge circuit to form a H-bridge configuration. The secondary winding is disposed in the rectifying/smoothing circuit.

System Identification and Controller Design of a Self-Sensing Piezoelectric Cantilever Structure:

Abstract: This paper addresses system identification and vibration control of a cantilever fabricated from piezoelectric materials, PZT, and shows how system identification and state estimation can be used to achieve self-maintenance of a self-sensing system. Currently, self-sensing systems that have concurrent actuation and sensing can be made by using a bridge circuit. However, hardware tuning is still needed due to the unstable nature of an imbalanced bridge circuit. This problem becomes serious in the space environment where human beings may not be available to perform the maintenance. A method of achieving self-sensing without a bridge circuit is proposed in this paper. Dynamics of this proposed system can be described as the state space expression with a direct transmission component. This means that the problem of balancing the bridge circuit is equivalent to the system identification and state estimation problem. By performing a simple experiment, a model of the system was identified using the 4SID, SubSpac...

Circuit configuration for load-relieved switching

Abstract: A circuit configuration for load-relieved switching has a bridge circuit with at least two controllable power switches, whose controlled paths are arranged in series with one another and between a first and a second supply potential. The circuit configuration has a drive circuit for driving the power switches, and an inductive element that is connected to output terminals of the bridge circuit. At least one power switch is designed as a field-effect-controllable, integrated transistor in accordance with the principle of charge carrier compensation or at least one power switch has deep pn junctions.

PWM/linear driver for an electromagnetic load

Abstract: The present invention relates a Pulse Width Modulation (PWM)/linear driver for an electromagnetic load by a bridge circuit of the type having a signal input and a signal output and at least two conduction control inputs for driving a voice coil motor in a linear mode and in a pulse width modulation. The bridge circuit is driven by a PWM converter coupled to one of said two control inputs and by a linear amplifier coupled to the other of said two control inputs.

Method of controlling series resonant bridge inverter circuit and the circuit

Abstract: PROBLEM TO BE SOLVED: To improve greatly the controllability in a light loading in a series resonant inverter circuit, and fulfill the increase in efficiency and the reduction in an output ripple. SOLUTION: In a controlling method of a series resonant bridge inverter in which semiconductor switches with anti-paralleled diodes are formed in full- bridge circuit, and which is comprised of an inductance 6 for use in resonance, a capacitor 5 for use in resonance and a load circuit 16 that are connected at an AC output side of the full-bridge circuit 2, the full-bridge circuit 2 is made to operate in a full-bridge form when an output electric power falls within the predetermined range of an electric power, and the full-bridge circuit 2 is made to operate on equivalent basis and in half-bridge form when an output electric power is smaller than the predetermined range of an electric power. COPYRIGHT: (C)2004,JPO

Method and related apparatus for controlling transmission interface between an external device and a computer system

Abstract: A method and a related apparatus for controlling a transmission interface between a computer system and an external device is disclosed. The external device includes a bridge circuit for controlling the transmission interface of the external device, a driver circuit for controlling the external device according to outputs of the bridge circuit, and a memory connected to the driver circuit for storing transmission interface data. Before the computer system obtains the transmission interface data, the bridge circuit transmits a control command to the driver circuit such that the driver circuit retrieves the transmission interface data stored in the memory, and transmits the transmission interface data to the computer system such that the computer system can properly transmit data to the bridge circuit according to the transmission interface data.

Device for side impact detection in a motor vehicle

Abstract: A device for side impact detection in a motor vehicle, and a plausibility sensor side impact detection. This plausibility sensor is located in a loudspeaker which is already present in the lateral part for playback of music. This loudspeaker is used as a low-frequency microphone, a circuit being provided for the loudspeaker to differentiate between sound and rapid fluctuations in air pressure. This circuit has a bridge circuit, the differential voltage across the bridge then being used as a plausibility signal. The circuit itself is preferably located in the door.

D.c. motor bridge coil driver

Abstract: An H-type, motor bridge, coil driver circuit, is implemented with an electronic switch in each leg segment of an H-shaped circuit, this bridge circuit having its side legs each connected between a power supply and ground, with the inductive load of a motor coil being connectable as the cross leg of the H-shaped circuit. The leg segment switches are operated as cross diagonal leg segment coordinated switches, with the pairs being exclusively in a conducting state, to energize the motor field coil from the power supply. An alternate current path, voltage level stabilizing element may be connected across each leg segment electronic switch. A coil excess energy storage element may be connected to the coil nodes of the circuit, through alternate current path elements and utilized to temporarily store the discharging of the excess coil energy normally available because of the lagging nature of the motor coil current. This temporary storage element then may discharge this energy back to the power supply through a passive circuit element. A cross coupling element connected between same leg, leg segment switches, is used to avoid cross conduction. Biasing current and electronic switch heat dissipation is enhanced by the substitution of composite circuit elements for in the leg segment electronic switches. Reverse polarity protection may be included for the power supply. Bi-directional current flow is achieved in the motor field coil.

Hybrid PWM rectifiers to reduce electromagnetic interference

Abstract: A hybrid PWM rectifier is proposed as a method to reduce the electromagnetic interference. The hybrid PWM rectifier consists of parallel-connected two component bridge circuits, that is, main and auxiliary bridge circuits. The main bridge circuit to handle the active power has a full current rating and a low switching frequency. The auxiliary bridge circuit to improve the input current waveform has a small current rating and a high switching frequency. Because the high-frequency switching of the full current can be avoided in the hybrid rectifier, the EMI can be reduced. The effectiveness of the proposed hybrid PWM rectifier is demonstrated by some experimental results.

Drive control for AC motor e.g. for numerically-controlled machine tool drive, provides integrated armature short-circuit braking function

Abstract: The drive control (A) uses a current regulator (W) with current control transistors (T1,..T6) connected in a bridge circuit, with separate devices (I1,I2) for pulse blocking of the transistors in the upper and lower arms of the bridge circuit, with armature short-circuit braking provided by switching all transistors of one bridge arm using a voltage (SV2') provided by a combining logic (N1,N2,V1,..V3,L1,..L4), with interruption of the pulse blocking control voltage (SV1,SV2).

Power management system for bridge circuit

Abstract: A power control signal controls a low-power mode, a USB connection, and an asynchronous reset function for a bridge circuit. Another power control signal controls both a high power mode and a low power mode for an attached device. The two power control signals reduce the number of pins required on the bridge circuit for controlling its own power related operations and power related operations of the attached device.

Design on semiconductor coupled SAW convolver

Abstract: This paper presents results of a design study on a semiconductor coupled surface acoustic wave (SAW) convolver in which bi-directionally propagating SAWs, on a piezoelectric substrate with a high coupling coefficient, couple with bonded semiconductor diodes through multistrips To obtain convolution signals with a high efficiency, we adopted a diode-balanced bridge structure for the nonlinear operation We also found that the tapping pitches of the multi-strip electrodes have robustness against operation frequency variation and temperature-dependent variation on the delay of the SAW We verified the effectiveness of the device in a circuit simulation and an experiment on a test circuit, which was fabricated by using an epitaxial lift-off film-bonding process

Precise Positioning Stage Driven by Multilayer Piezo Actuator using Strain Gauge

Abstract: A newly developed strain gauge with a Cr–N thin film was formed directly on a zirconia plate by sputtering without using any adhesive. Unevenness of sensitivity and drift caused by an adhesive layer could thus be suppressed. The gauge factor of the strain gauge was 6, three-fold that of a conventional strain gauge such as a Ni–Cu foil type. Four strain gauges were formed on one side of a zirconia plate. This zirconia plate was attached to sensor heads. When the sensor heads were moved, positive and negative strains were induced by a diaphram construction due to the use of a full-bridge circuit. A resistance of the strain gauge of 5 kΩ could be realized by thin and fine patterning in order to suppress joule heat. Therefore 10 V could be applied on a full-bridge circuit as bridge input voltage. The value was five-fold that of conventional bridge input voltage. By these improvements, higher sensitivity could be obtained and the S/N ratio could be improved. The precise positioning stage had a 5 nm resolution using this newly developed strain gauge as a displacement sensor.

Multi-processor system and method of assigning resource

Abstract: PROBLEM TO BE SOLVED: To provide a multi-processor system capable of efficiently using resources. SOLUTION: A plurality of bus bridge circuits 2 and memory controllers 3 are prepared, and the bus bridge circuits 2 are connected to a CPU 1, a core I/O bridge circuit 6, and an I/O bridge circuit 7 point-to-point. Accordingly, the partition/cluster inside a housing can be achieved, and resources including the CPU 1, a main memory 4, and devices under the control of the core I/O bridge circuit 6 and the I/O bridge circuit 7 can be kinetically assigned among nodes after the start of operation. COPYRIGHT: (C)2004,JPO

Flow rate measuring instrument

Abstract: The voltage for driving a bridge circuit (1) using a heating resistor (RH), a reference resistor (RR), and a pair of fixed resistors (R1, R2) connected to the heating and reference resistors in series respectively is controlled so as to balance the bridge circuit. The ambient temperature (TQ) of the reference resistor is calculated from the driving voltage of the bridge circuit and the output voltage from the bridge circuit. According to the ambient temperature and the rate of change (ΔP) of the flow rate per unit temperature of the sensor body, the flow rate measured by the sensor body is corrected, thereby measuring the flow rate with high accuracy independently of the ambient temperature and the flow rate of the fluid.

FFT analysis of the composite PWM voltage source inverter

Abstract: This paper describes a FFT analysis of the composite PWM voltage source inverter (VSI). The VSI has the normal single-phase bridge circuit and an additional arm. The composite PWM method contributes to reduce the ripple in the AC output current. The VSI has a LC series-resonance circuit tuned to twice the utility frequency connected in parallel with the smoothing capacitor Also, the smoothing capacitor is drastically reduced The smooth DC current is obtained by using the resonance circuit tuned to twice the AC source frequency.

Monolithic bridge circuit manufacturing method, by heating of anti-ferromagnetic layers to above blocking temperature and cooled so that it follows magnetization of adjacent magnetic reference layers

Abstract: The manufacturing method uses 4 magnetoresistive bridge elements, each provided with a magnetic reference layer (9) and an adjacent layer with natural anti-ferromagnet, the bridge element reference layers magnetized in at least 2 different directions via localized setting fields (Hext) provided via a field generator with current-carrying conductor paths (7). The bridge elements are heated to above the blocking temperature of the anti-ferromagnetic layer and subsequently cooled, so that the antiferromagnetic layer follows the magnetization of the adjacent reference layer. An Independent claim for a monolithic bridge circuit is also included.

Control apparatus of electric motor

Abstract: PROBLEM TO BE SOLVED: To detect failures in each switching element, using a simple structure, and to improve reliability by providing a resistor in the middle of a bridge circuit. SOLUTION: In a motor drive circuit 10, a resistor 24 for reference voltages, having a large resistance and voltage detection sections 25 and 30, are provided. Also, the voltage in middle wiring 15, when all FETs 11-14 are open, is stored at a storage section 19 in advance as a reference voltage VS. Then, when the motor drive circuit 10 is to be operated, a voltage VM of the middle wiring 15 is compared with a reference voltage VS by an MPU 18, while the FETs 11-14 are open, thus detecting short-circuiting of the FETs. Also, by successively closing only one FET among the FETs 11-14, disconnection in the FET can be detected. As a result, by allowing a small current to flow to the electric motor 4, failures in each FET can be detected.

Motor drive unit

Abstract: PROBLEM TO BE SOLVED: To provide motor drive circuitry wherein a current sensing resistor does not become common impedance for a next and following stage. SOLUTION: A motor drive circuit is connected with (n) loads and provided with at least n+1 output terminals OUT. Then, a pair of output terminals are allocated to one load to constitute a bridge circuit H. A control circuit 2 controls the opening and closing of a transistors Q belonging to the individual bridge circuit H, and thereby energizes the loads in the forward direction and reverse direction. Of the two pnp and npn transistors Q1 and Q2 connected to the specific output terminal OUT1, either is constant current-controlled with a feedback loop, and the other is constant current-controlled with an open loop. The load connected between the output terminal OUT1 and an adjacent output terminal OUT2 is constant current-driven by selectively using the feedback loop and the open loop according to the direction of the passage of a current. COPYRIGHT: (C)2004,JPO

Driving method of a bridge circuit for driving an inductance load

Abstract: A driving system of a bridge circuit for driving an inductance load turns OFF one of switching elements on either an upper arm connected to a power supply or a lower arm connected to a ground and turns ON the other one of the switching elements on the same arm when a pulse width modulation signal is OFF when a phase difference occurs between an electric current of a control signal with a sine wave and a voltage and when a polarity of the electric current differs from a polarity of the voltage, wherein the electric current is circulated via the other one of the switching elements, the flywheel diode connected to the one of the switching elements, and the inductance load.

Method and apparatus for measuring a fluid characteristic

Abstract: A tube through which fluid flows is installed in a fluid system. A piezoelectric driver is mounted on the exterior of the tube. A piezoelectric sensor is also mounted on the exterior of the tube. A feedback loop from the sensor to the driver is adapted to cause vibrations in the tube at its resonant frequency or a harmonic thereof. One or more strain gauges mounted on the exterior wall of the tube sense the strain exerted on the exterior wall by the pressure of the fluid flowing through the tube. A temperature sensor mounted on the exterior wall of the tube senses temperature. A microprocessor determines the density of the fluid flowing through the tube responsive to the piezoelectric sensor, temperature sensor and the one or more strain gauges. The one or more strain gauges comprise a bridge circuit. Strain gauges comprise two arms of the bridge circuit and temperature dependent resistors comprise the other two arms of the bridge. The output from the one or more strain gauges is used to correct the frequency reading given by the piezoelectric sensor.

Saturated magnetoresistive approach for linear position sensing

Abstract: A method and system for sensing linear position utilizing a magnetoresistive bridge circuit. A permanent magnet is provided having a gap formed therein. The magnetoresistive bridge circuit is generally located within the gap of the permanent magnet. The magnetoresistive bridge circuit includes a plurality of magnetoresistors. The magnet can be positioned in proximity to the ferrous target, which is associated with a slider that moves along a shaft. The magnetoresistive bridge circuit is generally biased by a magnetic field of the magnet. The magnetic field can saturate the magnetoresistive bridge circuit and a response of the magnetoresistors thereof. An output signal of the magnetoresistive bridge circuit can then be detected such that the output signal is produced by a change in an angle of the magnetic bias field. The output signal determines a target position with respect to a torque applied to the shaft.

Transformerless two-phase inverter

Abstract: A DC to two-phase AC inverter that includes three one-leg switch mode inverters circuits or a three-phase bridge circuit and a controller/driver circuit. The controller/driver circuit includes a triangular waveform generator and two sinusoidal reference waveform generators out of phase with each other, the sinusoidal waveforms generated at the desired AC output frequency, and the triangular waveform generated at a higher frequency. The controller/driver circuit is configured to drive one leg of the bridge circuit with a 50% duty cycle at the triangular waveform frequency and the other two legs at the triangular waveform frequency with pulse width modulated signals, the pulse widths of each signal varying with a discrete one of the sinusoidal waveforms. Each phase of two-phase AC is provided by the inverter between the leg driven at the 50% duty cycle and a discrete one of the other legs.

Optimization of structure and power supply conditions of catalytic gas sensor

Abstract: The analytical optimization of the structure and the power supply conditions of the catalytic gas sensor consisting of two spherical elements and connected to a Wheatstone bridge circuit is presented. Expressions for the parameters of the sensitive and reference elements and the catalytic gas sensor connected to the bridge circuit are obtained. The ratio of the sensitivity of the catalytic gas sensor to the bias voltage of the bridge circuit is chosen as a goal function and the heat balance equation for the element of the sensor in ambient air without combustible gases is used as a constraint. The diameter of the elements and the bias voltage of the bridge circuit are chosen as independent parameters. The optimization problem of the catalytic gas sensor is solved by its transformation to one parameter optimization problem without the constraint. Dependencies of optimum values of the goal function and corresponding values of the independent parameters, the sensitivity, the resistance of each element, the consumed power of each element and the current density flowing through the elements on the design parameters of the elements and their operating temperature are determined.

Gas sensor, and fuel cell system and car using the same

Abstract: PROBLEM TO BE SOLVED: To provide a gas sensor for detecting the amount of hydrogen without being affected by the influence of vapor under environment where hydrogen and the vapor coexist SOLUTION: The gas sensor comprises a first reference element 2a where a first thermistor 7a is sealed into a first nonporous case 11b with dry air; a first detection element 1a where the second thermistor 7a is put into a first perforated case 11a; a second reference element 2b where the third thermistor 7b that has nearly the same temperature - resistance characteristics and different moisture absorption characteristics as compared with the first thermistor 7a is sealed into the second nonporous case 11b nearly in the same shape as the first nonporous case 11b; and a second detection element 1b where the fourth thermistor 7b is put into a perforated case 11a nearly in the same shape as the first perforated case 11a A first bridge circuit comprises the first reference element 2a and the first detection element 1a, a second bridge circuit comprises the second reference element 2b and the second detection element 1b, and hydrogen concentration is obtained from the differential output of the bridge circuits COPYRIGHT: (C)2004,JPO