153results about "Reference comparison" patented technology

A capacitance measurement circuit includes an operation amplifier; a reference capacitor having a first terminal coupled to a first input terminal of the operation amplifier and a second terminal selectively coupled to a first or second reference voltage; a sensor capacitor having a first terminal coupled to a second input terminal of the operation amplifier and a second terminal selectively coupled to the first or second reference voltage; an approximation unit having an output terminal and an input terminal coupled to an output terminal of the operation amplifier; a conversion unit having an output terminal and an input terminal coupled to the output terminal of the approximation unit; and a coupling capacitor having a first terminal coupled to the first or second input terminal of the operation amplifier and a second terminal coupled to the output terminal of the conversion unit.

A method and circuit for controlling current through an inductive load such as an electromagnetic valve of a vehicle anti-lock braking system includes first and second driver stages, controlled by PWM (pulse width modulation) signals, for providing, respectively, an actuation path for valve current in an “on” phase and a recirculation path for valve current in an “off” phase. A peak value of current flowing in the actuation path at the end of an “on” phase is compared with a peak value of current flowing in the recirculation path at the start of the “off” phase in order to detect any malfunction of the circuit. An embodiment of the invention has the advantage of being able to detect any malfunction at very low and very high PWM duty cycles.

The invention belongs to the technical field of sensors, and discloses a nonlinear compensating circuit of a resistance bridge type sensor. The nonlinear compensating circuit comprises the resistance bridge type sensor, an excitation voltage source and a signal amplification circuit; a common mode resistor is connected between the resistance bridge type sensor and the negative end of a bridge power supply source in series; the output end of the signal amplification circuit is connected with the common mode resistor in series through a feedback resistor. The nonlinear compensating circuit has the advantages that signals (voltage) obtained after outside information sensed by the resistance bridge type sensor is converted are/is amplified through the signal amplification circuit, after pressure parting is carried out on the resistance bridge type sensor and the common mode resistor with the appropriate proportion (by changing the feedback resistor), and nonlinear compensating for the resistance bridge output type sensor with the gradually-increased output signal sensitivity is accordingly achieved. In addition, the signal amplification circuit in a circuit can be a digital programmable amplifier, the digital debugging zero position and the full scale can be applied, and the problems of low accuracy and poor stability caused by resistor replacement in the debugging process are solved. The measurement accuracy and the stability of the sensor are improved.

Method and system for measuring the resistance of a resistive structure having at least three nodes. A first calibration signal is determined by measuring a voltage at an output of the resistance structure when no calibration current is injected into a third node between the first and second nodes of the structure. A calibration current is then injected into the third node and a second calibration signal is determined. The absolute value of the difference between the first calibration signal and the second calibration signal is determined, the absolute value being proportional to a product of the resistance of the resistive structure and the calibration current.

An arc detection means for detecting arcs in a plasma process includes at least one comparator to which an evaluation signal such as an output signal or an internal signal of an AC generator relating to the output signal and a reference value are supplied. The comparator is connected to a logic component that generates a signal for an arc suppression device.

A method of fault detection of a belt or rope includes interconnecting a plurality of cords of the belt or rope, the cords including a plurality of wires, to form a bridge circuit. A fault detection bridge circuit is subjected to a voltage excitation and outputs a voltage which is indicative of the belt or rope damage but remaining insensitive to other environmental noises.

In accordance with an embodiment, a method of performing a measurement with a capacitive sensor includes generating a periodic excitation signal that includes a series of pulses and smoothing edge transitions of the series of pulses to form a shaped periodic excitation signal that includes a flat region between the smoothed edge transitions. The method further includes providing the shaped periodic excitation signal to a first port of the capacitive sensor and measuring a signal provided by a second port of the capacitive sensor.

The embodiments of the invention relates to offset error compensation systems and methods in sensors. Embodiments relate to reducing offset error in sensor systems. In embodiments, the sensitivity and offset of a sensor depend differently on some parameter, e.g. voltage, such that operating the sensor at two different values of the parameter can cancel the offset error. Embodiments can have applicability to stress sensors, Hall plates, vertical Hall devices, magnetoresistive sensors and others.

This invention relates to one meter device and its method and especially to one integral test device and method of low temperature current comparer device, wherein, the said test device comprises two sets of coils to be tested and the two sets coils are same and different polarization; it comprises main current source and passive current source, zero device and non-balance magnetic tester SQUID. This invention can test whole test in real time work status of the current comparer uncertain proportion.

A direct current measuring apparatus includes a voltage generating part generating a voltage to be applied to a load being a measuring object; a current limiting part limiting a current flowing in the load to a set value; and an output terminal connected to the load. The current limiting part includes a D/A converter, a positive side limiting circuit, a D/A converter and a negative side limiting circuit. The positive side limiting circuit includes a negative feedback loop. The negative feedback loop includes a capacitor and a buffer circuit besides the feedback resistance. An output of the positive side limiting circuit positive side limiting circuit is connected to a non-inverting input terminal of the main amplifier through a diode.

The invention relates to a thin-film magnetoresistive sensor element. The thin-film magnetoresistive sensor element comprises a lower electrode, a seed layer, an anti-ferromagnetic pinning layer, magnetic nail-pinning layer structure, a non-magnetic isolation layer, a magnetic free layer, a protecting layer, an upper electrode and a magnetic biasing layer. The invention also relates to a bridge for the thin-film magnetoresistive sensor. The thin-film magnetoresistive sensor element and the bridge thereof disclosed by the invention have the characteristics of small magnetic retardation, high precision and linearity, adjustable linear range, simple process, high response frequency, low cost, strong anti-jamming property and favorable temperature characteristic.

A method and a system for detecting and processing one or more deviations from an acceptable electrical behavior at a point of interest in an electrical network, the system comprising a voltage sensor and/or a current sensor, a measurement-processor configured to process measurements received from the at least one of a voltage sensor and a current sensor, at least one storage for storing one or more acceptable values related to the electrical behavior at the point of interest, and a deviation-processor, the deviation processor is configured to receive one or more detected values related to the electrical behavior at a point in time at the point of interest and detect one or more deviations between the one or more acceptable values and the one or more detected values, and analyze one or more deviations between the one or more acceptable values and the one or more detected values.

A balanced bridge comprises an input signal source, a reference impedance, an impedance to be tested, a bridge balancing module and a balance control module. The reference impedance is serially connected with the impedance to be tested and connected with the input signal source and is used for obtaining current vectors. The bridge balancing module comprises a reference impedance current extraction unit and an impedance to be tested current extraction unit and is used for providing bridge output pressure for the balance control module. The reference impedance current extraction unit is coupled to two ends of the reference impedance, the impedance to be tested current extraction unit is coupled to two ends of the impedance to be tested, and an output port of the bridge balancing module is an output port of bridge output pressure. The balance control module comprises a pressure detection module, a feedback circuit module and a single chip microcomputer, wherein one end of the pressure detection module is connected with the output port of bridge output pressure, the other end of the pressure detection module is connected with the single chip microcomputer, the other end of the single chip microcomputer is connected with the feedback circuit module, and the feedback circuit module is coupled to the impedance to be tested current extraction unit.

The invention discloses a high-precision electromigration early warning circuit, which comprises an interconnection wire testing structure, a two-stage low-gain amplifier, a high-gain comparator and an output stage. An output end of the interconnection wire testing structure is connected with an input end of the two-stage low-gain amplifier; an output end of the two-stage low-gain amplifier is connected with an input end of the high-gain comparator; and an output end of the high-gain comparator is connected with the output stage.

A differential current measuring module is composed of a housing that encases a current transformer core and a printed circuit board, the current transformer core surrounding a line duct of the housing and having at least one secondary winding. The differential current measuring module is characterized in that in the line duct, at least one primary conductor is led out on a top side of the housing to be connected to an external electrical feed line and whose other end protrudes out of a bottom side of the housing and is provided with a solder terminal. The principle idea is based on continuing the electrical line to be monitored, in sections, as a primary conductor in the effective area of the current transformer core so as to advantageously arrive at a differential current measuring device whose integration is constructionally simple and which offers an uncomplicated connecting option.

Disclosed is a magnetoresistive magnetic field gradient sensor, comprising a substrate, a magnetoresistive bridge and a permanent magnet respectively disposed on the substrate; the magnetoresistive bridge comprises two or more magnetoresistive arms; each magnetoresistive arm consists of one or more magnetoresistive elements; each magnetoresistive element is provided with a magnetic pinning layer; the magnetic pinning layers of all the magnetoresistive elements have the same magnetic moment direction; the permanent magnet is disposed adjacent to each magnetoresistive arm to provide a bias field, and to zero the offset of the response curve of the magnetoresistive element; the magnetoresistive gradiometer includes wire bonding pads that can be electrically interconnected using wire bonding to an ASIC or to the lead frame of a semiconductor chip package.

An all-turn off detection circuit for a thyristor in a cycloconverter system, belongs to the technology of thyristor conversion, and consists of a voltage detection circuit and a logic judgment circuit; wherein, the input of a voltage detection circuit is the terminal voltage of the thyristor, an output signal is transmitted to a logic judgment circuit which outputs an all-turn off detection signal. Detection of voltage at the two terminals of the thyristor is realized through the voltage detection circuit. The logic judgment circuit makes logic judgment by utilizing a trigger signal and a voltage detection signal, providing an on-off signal of the thyristor. The utility model has the advantages of rapidly and precisely providing the zero current information of a main circuit, greatly shortening the dead time of zero current in the shift between positive and negative groups, reducing the negative impact on motor load.