69 results about "Electrical capacitance meter" patented technology

The invention relates to a detection device and method for rebar in concrete, and provides a static field capacitance principle-based low-cost, high-accuracy and nondestructive detection device and method. Various types of targeted detection are implemented on the rebar in the concrete, and an accurate and convenient detection result comprising rebar position, size and corrosion quantity is expected to be acquired, and operation efficiency of detection, building engineering acceptance and detection, reinforcement and identification of an existing rebar concrete structure are improved. The detection device comprises an electrode plate, a DC power supply and a data acquisition processing device, wherein the data acquisition processing device comprises a capacitance meter, a display module, an operation module, a processing module and a data connection line socket, wherein an angular frequency of the capacitance meter is set as 10KHz, the display module is used for displaying a numericalvalue obtained after detection of a capacitance sensor, the operation module is used for performing artificial actual operation and inputting special engineering information to set a parameter, the processing module is used for performing data analysis statistics on the numerical value measured by the capacitance meter and other relevant numerical values, and the data connection line socket is used for connecting the electrode plate.

The invention discloses a voltage measurement self-decoupling method based on multi-dimensional equivalent capacitance calculation. The method comprises the following steps: 1) determining the type of a power transmission line to be measured; 2) performing non-contact measurement on the voltage of the to-be-measured power transmission line by using a non-contact electric field sensor, and establishing a self-decoupling matrix of the to-be-measured power transmission line; 3) judging whether the sensor is symmetrically distributed based on x and z axial directions, and resolving a self-decoupling matrix; 4) performing singularity verification on the self-decoupling matrix, if the self-decoupling matrix has singularity, determining that the position of the non-contact electric field sensor is a singular measurement point, replacing the position of the non-contact electric field sensor, and returning to the step 2), and if the self-decoupling matrix has non-singularity, entering the step 5); and 5) calculating a three-phase voltage signal of the power transmission line to be measured. According to the invention, the size of the signal is actually measured through the sensor, the multi-terminal voltage signal characteristics of the power transmission line are accurate, the accuracy of the decoupling algorithm is improved, and the design difficulty caused by repeated correction is effectively reduced.

A capacitance meter including an AC source providing a measurement voltage with a measurement frequency to a capacitor. A current sensor is arranged to measure a current going to or from the capacitance meter. A voltage sensor is arranged to measure a voltage over the capacitor. A capacitance calculation unit is arranged to calculate, using a controller, a capacitance of the capacitor using a measured current from the current sensor, a measured voltage from the voltage sensor and the measurement frequency. The capacitance meter is arranged to obtain measurements using the current sensor and the voltage sensor during a measurement duration. The measurement frequency and the measurement duration are selected such that the measurement duration equals a multiple of the period of the measurement frequency, and the measurement duration equals a multiple of the period of a mains electricity.

A method of calculating electrical interactions of circuit elements in an integrated circuit layout without flattening the entire database that describes the layout. In one embodiment, a hierarchical database is analyzed and resistance and capacitance calculations made for a repeating pattern of elements are re-used at each instance of the repeated pattern and adjusted for local conditions. In another embodiment, a circuit layout is converted into a number of tiles, wherein the resistance and capacitance calculations made for the circuit elements in the center and a boundary region of the tiles are computed separately and combined. Environmental information that affects electrical interaction between circuit elements in different levels of hierarchy is calculated at a lower level of hierarchy so that such calculations do not need to be made for each placement of a repeated cell and so that not all interacting elements need to be promoted to the same hierarchy level to compute the electrical interactions.

A relative-dielectric-constant measuring apparatus according to the present invention includes an ellipsometer and a capacitance measuring part. The ellipsometer allows non-contact measurements of the film thickness and optical constants of an insulation film formed on the upper surface of a wafer. The capacitance measuring part, on the other hand, allows non-contact measurements of the gap between the insulation film and an electrode and accumulation capacitance. The relative-dielectric-constant measuring apparatus can calculate the relative dielectric constant of the insulation film based on the measured film thickness, gap, and accumulation capacitance. Thus, the relative dielectric constant of the insulation film can be determined without contact and with high precision.

The present invention relates to a method for measuring the active area of an active material in an electrode, comprising: manufacturing three types of electrodes including a first electrode coated with an electrode mixture including both an electrode active material and a conductive material, a second electrode coated with an electrode mixture which includes the electrode active material as a main ingredient and does not include the conductive material, and a third electrode coated with an electrode mixture which does not include the active material and includes the conductive material as a main ingredient; a cell manufacturing step of manufacturing three types of monocells by using the same types of electrodes; a capacitance measuring step of measuring, from the monocells, capacitance of each electrode used in the monocells; and an active area calculating step of calculating the active area of the electrode active material from the capacitance.

The present application discloses a parameter design method for an electric field coupled wireless power transfer system with constant current output. On the basis of analyzing the total input impedance of the electric field coupled wireless power transfer system, the conditions for constant output current and the current during constant current output are deduced. Gain expression, determine the operating frequency and compensation capacitance of the system according to the current gain expression and the area of ​​the coupler as a constraint; calculate the compensation inductance according to the constant output current condition and the determined operating frequency and compensation capacitance; if any of the compensation inductance If one is greater than the preset inductance threshold, modify at least one of the operating frequency and the compensation capacitor until the compensation inductance is not greater than the inductance threshold; simulation experiments are carried out on the system parameters designed based on this method, and it shows that the system output current has nothing to do with the load impedance; This design method solves the problem of unstable output current when the system load impedance changes, and makes the system have excellent constant output current characteristics.

A method for detecting presence of an interference source is to be performed by a touch sensing system that stores a threshold capacitance difference. The method includes the steps of sampling capacitances periodically within a time period for obtaining a base capacitance value; sensing a comparison capacitance after the time period; computing an absolute difference between the comparison capacitance and the base capacitance value; and determining that the interference source is present when the comparison capacitance is smaller than the base capacitance value and the absolute difference is greater than the threshold capacitance difference.

The invention provides a control method of a door closing resistance self-adaptive elevator door motor. The control method of the door closing resistance self-adaptive elevator door motor comprises the following steps of: S1, judging whether no passenger or no foreign matter exists in an elevator door closing stroke or not in real time, and if so, performing S2; if not, performing S4; S2, obtaining capacitance between elevator doors on the two sides through a capacitance sensor, calculating the movement speed between the elevator doors on the two sides, judging whether the door closing resistance is larger than a threshold value or not according to the movement speed, if yes, executing a step S3, and if not, executing the step S4; S3, enabling a door motor controller to reduce the operation speed of a door motor to a first speed V1 and increase the door closing torque until the doors are closed; and S4, enabling the door machine controller to control the door machine to operate at the normal speed V0 and control the door closing moment to be the normal door closing moment until the doors are closed. According to the control method of the door closing resistance self-adaptive elevator door motor provided by the invention, the actual closing speed of the elevator doors is monitored in real time, the actual closing speed of the elevator doors is used as a condition for judging whether the closing resistance of the elevator doors is too large or not, and the reliability is high aiming at all factors except the air outlet force.

The invention belongs to the technical field of special vehicle comprehensive power system high-voltage safety protection, and particularly relates to an electrically-driven special vehicle distributed capacitance testing device which comprises a precise current source, a reference voltage source, an electronic switch, a voltage comparator, an electronic switch control unit and a single-chip microcomputer. The device enables the reference voltage source to charge the distributed capacitor through switching the electronic switch, discharges the distributed capacitor through the precision current source, records the discharge time of the distributed capacitor through the single-chip microcomputer, and obtains the capacitance value of the distributed capacitor according to a capacitance calculation formula. The circuit realizes the distributed capacitance detection function of the electrically-driven special vehicle, can measure the distributed capacitance value of the vehicle, and provides a basis for the duration of applying insulation detection excitation voltage to an on-vehicle insulation detection device. And meanwhile, an electric leakage subcircuit of the vehicle caused by distributed capacitance is effectively evaluated, the electric shock risk of personnel is reduced, and the safety of personnel and equipment on the vehicle is effectively ensured.

The invention provides a method, a device and a system for testing the capacitive current. The method comprises the following steps: respectively and electrically connecting the test terminals of thecurrent output module of a capacitive current testing device with the A-phase terminal, the B-phase terminal and the C-phase terminal of a switch cabinet electrified indication device; electrically connecting the grounding terminal o of the capacitive current testing device with the grounding terminal of the switch cabinet electrified indication device; electrically connecting a current transformer of each phase between the capacitor of a corresponding electrified indication sensor and the capacitor of a switch cabinet electrified display device; outputting an abnormal-frequency current signal; acquiring an abnormal-frequency voltage and an abnormal-frequency current corresponding to each phase of the an abnormal-frequency current signal; calculating the ground capacitance of each phase ofa neutral point ungrounded system; according to the ground capacitance of each phase, calculating to obtain the ground capacitance current. According to the invention, the test loop is simple. The ground capacitance of each phase of the power system, relative to the ground, can be calculated respectively. Meanwhile, the condition of power outage is not required and the safety is high. The methodcan be used for testing the capacitive currents of ungrounded systems.

The invention discloses a distribution network grounding fault identification method, device and equipment. The method first establishes that a small current signal with the same amplitude and frequency conversion is injected from the neutral point of the distribution network, and the voltage signal fed back is measured through a voltage transformer, thereby Calculate the conductance and capacitance to ground of the distribution network, and then use the conductance to ground and capacitance to ground to calculate the incremental damping rate at each frequency, and then calculate the incremental damping rate generated by the fault transition resistance and superimpose Faults are carried out according to preset criteria to achieve effective amplification of fault characteristic quantities, and at the same time greatly reduce the impact of interference, thereby effectively identifying high-resistance grounding faults. The invention solves the problem of difficult identification of high-resistance ground faults in a resonant ground distribution network, can highlight the characteristics of ground faults, has high anti-noise ability, and greatly improves the identification ability of high-resistance ground faults.