61 results about "Capacitance bridge" patented technology

The invention relates to a power converter, which is composed of three bridge arms connected in parallel and then connected in parallel with a working capacitor; and between the midpoints of the first bridge arm and the second bridge arm, there is a commercial power input and an inductance connected in series, and the second bridge arm The primary side of the transformer is connected in series between the midpoint of the arm and the third bridge arm, and the negative side of the transformer is connected to the DC output circuit; the control terminals of the first bridge arm, the second bridge arm, and the third bridge arm are all connected to the control circuit The control signal is connected; wherein the control circuit selectively controls the conduction of the switch tube corresponding to the first bridge arm and the second bridge arm according to the detection result of the zero-crossing voltage input by the mains to perform power factor correction. The control circuit also detects the load The operating state parameters selectively control the conduction of the switch tube of the third bridge arm to output energy to the secondary side of the transformer so that the DC output circuit outputs DC; the present invention combines AC anti-surge, rectification and filtering, PFC conversion, DC/ The DC is designed together, and only six switching tubes are used to complete the power conversion.

In a method for determining capacitance, a first time-varying signal is driven on a first terminal of a first capacitor and a second time-varying signal is driven on a first terminal of a second capacitor, where the first time-varying signal and the second time-varying signal have a pre-determined phase relationship with each other.

These signals are received on second terminals of the first capacitor and the second capacitor and demodulated using a periodic signal to produce demodulated signals. This periodic signal has the same fundamental frequency as the first time-varying signal and the second time-varying signal. A DC component in the demodulated signals is then determined by filtering the demodulated signals, and the sign of the DC component is used to determine a relative capacitance of the first capacitor and the second capacitor.

The invention discloses a method for improving output power of a photovoltaic module; serial-connected photovoltaic cell elements in the photovoltaic module are divided into groups uniformly, the output voltage ratio of the two adjacent photovoltaic cell element groups is ensured to be equal to the voltage ratio of the maximum power points of the adjacent photovoltaic cell element groups. According to the condition that the photovoltaic cell elements are divided into two groups uniformly, a correcting circuit is provided; the correcting circuit comprises a P channel MOSFET pipe, an N channel MOSFET pipe, an inductor and two capacitors; wherein, the drain electrode of the P channel MOSFET pipe is serially connected with the drain electrode of the N channel MOSFET pipe for forming a MOSFET bridge arm, the two capacitors are serially connected into a capacitance bridge arm, the MOSFET bridge arm is connected with the capacitance bridge arm in parallel, the connecting point of the two MOSFET pipes is connected with the connecting point of the two capacitors by the inductor. The energy conversion efficiency of the photovoltaic module is effectively improved under the condition of local shadow; in the method of the maximum power point tracking of the photovoltaic module of the invention, a normal tracking method can be avoided from falling into a local extreme point.

An infrasound testing device consists of an infrasound sensor, a lowpass, an analog-digital converter, an SCM and an LCD which are respectively connected with a battery, wherein, the output end of the infrasound sensor is connected with the input end of the lowpass, the output end of the lowpass is connected with the input end of the analog-digital converter, the output end of the analog-digital converter is connected with the input end of the SCM, and the output end of the SCM is connected with the LCD. An amplitude modulation principle is utilized to measure the slow changes of a capacitance microphone, an acoustic compliant element in the infrasound sensor acts as an arm of the capacitance bridge, the input end is connected with a high-frequency voltage with same amplitude, when the infrasound wave acts on the film, the film generates a displacement with the change of the sound pressure, which result in the capacitance changes of the plate capacitor, so that the balance of the capacitance bridge is changed, therefore, the output end can obtain amplitude modulation wave modulated by the capacitance change, the amplitude modulation wave is sent to a modern after the voltage is amplified, then the low-frequency electrical signals are gained, and the detection of the infrasound wave is achieved.

The invention provides an MEMS accelerometer reading circuit which comprises an output module. The output module is an output conversion module including differential output and single-end output, and the output conversion module is of a two-end differential type signal detection and processing structure. A capacitance bridge is built outside, can be applicable to various accelerometer headers and solves the direct-current deviation problem. Circuit precision is high, and the resolution ratio of output signals is high.

The invention discloses a zigzag connection soft switching hybrid-type multi-level DC interconnection current transformer and belongs to the technical field of intermediate and high voltage DC power transmission and distribution. The current transformer includes a bridge-type chopper, a power electronics capacitance bridge arm and two identical power electronics reactance bridge arms. Two bridge arms of the bridge-type chopper are each composed of two power electronics serial switch blocks connected in series. The positive electrode of the bridge-type chopper is connected to a high voltage positive electrode terminal of the current transformer while the negative electrode is connected to a high voltage negative terminal of the current transformer. The positive electrode of the capacitancebridge arm is connected to the high voltage positive electrode terminal of the current transformer while the negative electrode is connected to the high voltage negative electrode terminal of the current transformer. The positive electrodes of the two reactance bridge arms are connected to middle points of the two bridges arms of the bridge-type chopper respectively. The negative electrodes of thetwo reactance bridge arms are both connected to a low voltage positive terminal of the current transformer. According to the invention, a voltage-transformer-free non-isolation method is adopted forrealizing power conversion of different DC voltage levels, so that all switch devices in the power electronics serial switch blocks realize zero-current current transform soft switching, advantages ofhigh conversion efficiency, low loss, easy implementation of dynamic voltage sharing and high economic cost are achieved.

The invention discloses a non-contact micro-cantilever beam rigidity measurement method based on an electrostatic force. The method comprises the following steps: establishing an experimental platform, controlling a nanometer micropositioner to drive a micro-cantilever beam to be tested to perform periodic equidistant stepping motion on a vertical direction, measuring a capacitance change betweenthe micro-cantilever beam to be tested and a plate electrode in real time by using a capacitance bridge, and performing mathematical treatment on the experimental data; and using a DC power source toload a periodic equidistant stepping voltage between the micro-cantilever beam to be tested and the plate electrode, using a laser interferometer to measure the displacement change of a free end of the micro-cantilever beam to be tested in real time, and performing mathematical treatment and fitting on the experimental data to obtain a rigidity measurement value of the micro-cantilever beam to betested. The non-contact micro-cantilever beam rigidity measurement method disclosed by the invention is based on the Hooke's law, the electrostatic force is used as the load, the nanometer micropositioner, the capacitance change, a stabilized voltage supply and the like are adopted, a micro-cantilever beam rigidity measurement platform is established, a mathematical relationship among the micro-cantilever beam rigidity, an interelectrode voltage and the displacement of the free end is established, and the non-contact measurement of the rigidity of the cantilever beam is achieved.

The invention discloses a method and a device for measuring parameters of a micro solid gyroscope equivalent circuit. The micro-solid modal gyro equivalent circuit is formed by two branches in parallel connection, wherein one branch includes a static capacitance circuit, and the other branch is a serial-connection circuit of a dynamic resistor, a dynamic capacitor and a dynamic inductor. The device comprises a variable-frequency oscillator, two terminal networks and a detector. The variable-frequency oscillator supplies a constant current to the measurement circuit and the detector is a voltage meter and is used for detecting voltage across two ends of each terminal network when the frequency is varied. The measurement method which utilizes the measurement device and is based on a maximal output frequency and a capacitance bridge can be used for solving each parameter of the equivalent circuit. In order to improve the analyzability the micro-solid modal gyro in a driving or a detecting equivalent circuit, the method and the device for measuring the parameters of the micro-solid modal gyro equivalent circuit are very necessary to provide.

A bridge accelerometer system includes four capacitors, wherein two capacitors are formed on each side of a rigid member. The other two capacitors are similarly constructed, except that the rigid member is replaced by a flexured plate. The construction of the plates with respect to the flexured plate is substantially similar to the configuration formed by the rigid member and the other two capacitors, and the fixed capacitors and rigid plate are isolated from the flexured arrangement. The four capacitors are connected to form a bridge generating a bridge voltage signal as a function of a sine wave from a symbol generator. The bridge voltage signal is amplified and converted to digital word in an A/D converter. The digital word is linearized and filtered in a microprocessor, which also includes a precision clock controlling the symbol generator and a conversion clock controlling the A/D converter.

The invention provides a passive temperature measuring sensor of substation primary equipment. The passive temperature measuring sensor comprises a radio frequency receiving circuit, a temperature sensing circuit, a digital logic circuit and a storage unit. The radio frequency receiving circuit comprises a coupling element, a rectifying circuit, a voltage stabilizing circuit and a modulation and demodulation circuit. The temperature sensing circuit comprises a capacitance temperature measuring circuit and an analog-digital converter. The digital logic circuit comprises a coder/decoder and a logic controller which is in bidirectional signal electric-connection with the coder/decoder. The radio frequency receiving circuit responds to excitation signals in the frequency same as or approximate to inherent frequency of the coupling element and selectively senses the temperature of detected equipment by means of frequency of surface acoustic wave coupling element. The capacitance temperature measuring circuit measures capacitance-temperature characteristics, maps the relation of capacitance and temperature, and outputs signals corresponding to the temperature according to the capacitance bridge theory. The passive temperature measuring sensor adopting the passive temperature measurement technology is high in interference resistance and applicability, high in integrity, convenient in implement and low in cost.

A fluid level sensor comprises a parallel plate capacitor coupled to an integrated circuit located in the bottom of an oil pan or other receptacle in which fluid level is being sensed. The sensor is preferably mounted on a drain plug for the receptacle. It includes an integrated circuit board encapsulated in a potting material disposed within the drain plug and a probe extending upwardly from the integrated circuit with its lower end also encapsulated with a resin such that its leads are protected by the resin encapsulating the integrated circuit. The probe may include one or more slotted plates in which capacitance bridges are formed within the slots or a plurality of parallel plates in which capacitance bridges are formed between adjacent plates. The sensor can be used to control operation of a gauge and/or an ignition control circuit for the machine's engine.

The invention discloses a power factor correction method based on a double-inductor double-voltage DC output circuit. The double-inductor double-voltage circuit comprises an uncontrolled rectifier bridge circuit, a capacitance bridge circuit and a voltage division circuit, which are connected in parallel. The uncontrolled rectifier bridge circuit comprises a first bridge arm and a second bridge arm. The voltage division circuit comprises at least two resistors, which are connected in series in sequence. The voltage division circuit is provided with a DC side sampling end. The first bridge arm and the second bridge arm of the uncontrolled rectifier bridge circuit are connected with a power live wire and a power zero wire respectively, and a dual-gate switch is arranged between the power live wire and the power zero wire to form an input voltage and input current sampling end. A first power inductor L1 and a second power inductor L2 are arranged between the first and second bridge arms of the uncontrolled rectifier bridge circuit and the capacitance bridge circuit respectively. The method carries out inner-ring power factor correction on input voltage ui and input current iL collected at the input voltage and input current sampling end and carries out outer-ring voltage control on the output voltage uo collected at the DC side sampling end of the voltage division circuit.

The invention discloses a determination method for distributed MEMS (micro-electromechanical systems) phase shifter capacitance bridge height tolerance based on electromechanical coupling. The determination method comprises the steps of 1) determining structural parameters, material attribute and electromechanical working parameters of the distributed MEMS phase shifter; 2) determining equivalent circuit parameters of the phase shifter; 3) determining a digit k of the phase shifter; 4) determining a standard capacitance bridge height of the phase shifter; 5) providing offset of initial capacitance bridge; 6) calculating phase shifting amount generated by single capacitance bridge by using an electromechanical coupling model of the single capacitance bridge; 7) calculating phase shifting amount of the phase shifter; 8) calculating deviation value of the phase shifter; and 9) judging whether the deviation value of the phase shifter satisfies the tolerance requirement or not under the condition of the capacitance bridge height. The influences on the phase shifting amount of the phase shifter by the capacitance bridge structural parameters are directly obtained by using the electromechanical coupling models between the phase shifter capacitance bridge structural parameters and the phase shifting amount, so that reasonable capacitance bridge structural tolerance precision can be rapidly provided, the processing cost and processing difficulty are lowered, and the research and development period is shortened.

The invention relates to a capacitance human body approach alarming control device. The alarming control device comprises a 220V alternating current power supply, a 12V direct current power supply, a capacitance bridge circuit, a differential pressure signal detecting circuit and a differential pressure signal amplifying and alarming control circuit, wherein the capacitance bridge circuit comprises capacitors C1-C4; the differential pressure signal detecting circuit comprises Schottky diodes D1-D4; certain defects exist in certain finished product monitoring devices or facilities on the market; and the capacitance human body approach alarming control device is designed in order to solve or make up the certain defects existing in various monitoring devices on the market, higher selling prices and other problems. The capacitance human body approach alarming control device is mainly used for detecting whether a human body approaches a fortification area, is flexible and various in the monitoring mode and is not limited by factors such as the size of monitoring areas or properties of articles and the like; when certain cases happen, the alarming device acts dexterously and solves the problems of misinformation of non-substantiality conditions and failed reporting of dangerous warning conditions; four monitoring passageways can be simultaneously used; and a part of monitoring passageways can be used according to the need.

The invention relates to the pressure measurement field, in particular to a high static pressure resistant dynamic pressure measurement proposal. The proposal is realized through the following technical measures: a by-pass passage connected with a main passage is provided; the by-pass passage comprises a sampling passage and a damping passage, wherein the damping passage is connected with one side of a differential pressure measuring and transmitting device, the sampling passage is connected with the other side of the differential pressure measuring and transmitting device, and the measured pressure signals on the two sides are outputted after treatment of a capacitance bridge. The proposal has simple method, easy realization, and simple structure and convenient assembly of realization form; the dynamic pressure signals are outputted according to a 4-20mA standard.

The invention relates to an AC frequency conversion speed regulating technique of an asynchronous motor, in particular to an AC frequency converting apparatus of a feedback-free type asynchronous motor. The invention solves the problems that the asynchronous motor has wattles current and loss in the processes of converting frequency and regulating speed, and the prior frequency converting apparatus has higher cost, can not fully balance the wattles power and does not have ideal energy-saving effect. The AC frequency converting apparatus comprises a three phase rectifier bridge, and a three phase inverter bridge which is connected between DC output ends of the three phase rectifier bridge and consists of six thyristors, wherein three main capacitance bridge circuits respectively formed by connecting in serial with two power capacitors are connected between the DC output ends of the three phase rectifier bridge, three midpoints of the three phase inverter bridge lead out three ends respectively as one end of each phase of the three phase AC output, and the three midpoints of the three main capacitance bridge circuits lead out the other ends respectively as the other end of each phase of the three phase AC output. The AC frequency converting apparatus overcomes the significant defect of a series of loss caused by the feedback wattless current in the inverting process, and adopts ordinary thyristors, the power capacitors and a rectifying tube to form a main loop of the apparatus, thereby remarkably reducing the cost.

A grounding test apparatus of reversely connected flow ratio device high voltage bridge based on a cable insulation technique relates to the test apparatus. The invention is proposed to solve the problem that the present flow ratio device capacitance bridge is largely limited in working voltage, difficult in ground insulation and liable to cause electric shock when testing a grounding tested object. Both a passive flow ratio device bridge and an active flow ratio device bridge use a leader cable which is a high-voltage coaxial cable; the high voltage end of the leader cable is connected with a high voltage leading-out wire and the tested object end of the leader cable is connected with the grounding tested object. The high-voltage coaxial cable has excellent insulating property and can isolate the high voltage from a case body and other devices therein, complex ground insulation is unnecessary, and no accident of the electric shock takes place during high voltage test; the terminal of the leader cable employs two terminals including a taped terminal and a cold-shrinkage terminal, thus eliminating the limit of the working voltage, and simultaneously providing a new test apparatus that replaces the traditional reversely connected, diagonally-grounded Schering bridge for the test of the grounding tested object. The invention can be applied to passive and active balanced bridges.

The invention provides a system and a method for measuring response time of a cold air thruster based on a variable medium capacitance bridge. The system comprises a capacitance bridge circuit component and an operational amplifier circuit component. The capacitance bridge circuit component is connected with the operational amplifier circuit component; the capacitance bridge circuit component comprises a capacitor C1, a capacitor C2, a capacitor C3, a capacitor C4 and the cold air thruster; One end of the capacitor C1 is connected with one end of the capacitor C2; the other end of the capacitor C1 is connected with one end of the capacitor C3; the other end of the capacitor C2 is connected with one end of the capacitor C4; the other end of the capacitor C4 is connected with the other end of the capacitor C3; and the capacitor C4 is connected with the cold air thruster. Thrust signals are converted into voltage signals by adopting a variable medium capacitance bridge method, the signals are amplified by adopting an operational amplifier circuit, and finally mus-level signal acquisition can be realized through an oscilloscope so that the requirement of thrust response time is met.

The invention belongs to the technical field of security protection and electronic monitoring, and relates to a capacitance bridge type human body proximity alarm. The alarm comprises a 220V alternating-current power supply, a 12V direct-current power supply, a capacitance bridge circuit, a signal detection circuit, a signal amplification circuit and a sound-light alarm circuit. As certain finished monitoring devices or facilities in the market have certain defects, the capacitance bridge type human body proximity alarm is designed for solving the problems of certain defects, relatively high price and the like of various monitoring devices in the market. The monitoring alarm is used for detecting whether a human body enters a fortification region or not, and has the main functions and effects that firstly, monitoring modes are flexible and diversified and cannot be limited by factors such as the size of a monitoring region or the properties of an article; secondly, when a warning occurs, the sound-light alarming action of the monitoring device is quickly generated; thirdly, the problems of false alarming of non-substantial dangerous cases, missed alarming of dangerous cases and the like are solved; fourthly, the four monitoring channels of the alarm can be simultaneously used or part of the monitoring channels are used as needed.

The invention relates to the technical field of electric power test equipment metering, and discloses a high-voltage capacitance bridge automatic frequency locking device which comprises a test power supply, the output end of the test power supply is electrically connected with a tested device and a standard capacitor, and the output end of the tested device is electrically connected with a current comparator. According to the invention, when a signal transmitted from a tested device is transmitted to a frequency detector through a current comparator, the frequency detector detects the transmitted frequency, then adjusts the unbalanced frequency through an unbalanced current regulator, and transmits the frequency adjusted by the unbalanced current regulator to a frequency selector. The frequency selector amplifies the frequency through the frequency amplifier and then transmits the amplified frequency to the balance current display device for display, and through the application of the automatic frequency locking amplification device, the situation that the safety of a whole power grid is affected due to the fact that some specific harmonic waves are damaged is avoided.

The invention provides an N input single-phase N+1 switching group MMC rectifier and a control method of the N input single-phase N+1 switching group MMC rectifier. The rectifier comprises N alternating-current inputting power supplies, N alternating-current inductors, a capacitance bridge arm, a switching bridge arm and a rectification load. The capacitance bridge arm is formed by connecting N+1 capacitors in series and the switching bridge arm is formed by connecting N+1 switching groups, a first inductor and a second inductor in series. The ith switching group of the switching bridge arm is formed by connecting n power switching units in series, wherein i is selected between 1 and N+1. The two ends of the kth alternating-current power supply serve as inputting of the kth circuit, wherein k is selected between 1 and N. The N input single-phase N+1 switching group MMC rectifier is controlled through carrier phase-shifting PWM, the N input alternating current power supplies are converted into alternating current inputting of N circuits of n+1 levels and after currents are rectified and overlapped, the load is powered. The voltage stress borne by each switching tube in an MMC power switching unit is only one nth of the voltage of the direct-current power supplies and the problem of voltage sharing of the switching tubes is solved. The N input single-phase N+1 switching group MMC rectifier is applicable to multiple-alternating-current-power-supply-inputting, high-voltage and large-power occasions.