感容式节能镇流器的原理与设计

介绍了采用附加启动电感线圈的电感电容串联组合形式的感容镇流器，通过电路设计，达到节能和克服纯电感镇流器低压启动性能差等缺点。

A Novel Capacitive Biaxial Microaccelerometer Based on the Slide-Film Damping Effect

A novel capacitive biaxial microaccelerometer with a highly symmetrical microstructure is developed. The sensor is composed of a single seismic mass, grid strip, supporting beam, joint beam, and damping adjusting combs. The sensing method of changing capacitance area is used in the design,which depresses the requirement of the DRIE process, and de- creases electronic noise by increasing sensing voltage to improve the resolution. The parameters and characteristics of the biaxial microaccelerometer are discussed with the FEM tool ANSYS. The simulated results show that the transverse sensitivity of the sensor is equal to zero. The testing devices based on the slide-film damping effect are fabricated, and the testing quality factor is 514, which shows that the designed structure can improve the resolution and proves the feasibility of the designed process.

A Novel Capacitive Pressure Sensor

A novel capacitive pressure sensor is presented, whose sensing structure is a solid-state capacitor consisting of three square membranes with Al/SiO2/n-type silicon. It was fabricated using pn junction self-stop etching combined with adhesive bonding,and only three masks were used during the process. Sensors with side lengths of 1000,1200,and 1400μm were fabricated,showing sensitivity of 1.8,2.3, and 3.6fF/hPa over the range of 410～ 1010hPa, respectively. The sensi- tivity of the sensor with a side length of 1500μm is 4. 6fF/hPa,the nonlinearity is 6. 4% ,and the max hysteresis is 3.6%. The results show that permittivity change plays an important part in the capacitance change.

The Velocity Measurement of Two-phase Flow Based on Particle Swarm Optimization Algorithm and Nonlinear Blind Source Separation

In order to overcome the disturbance of noise,this paper presented a method to measure two-phase flow velocity using particle swarm optimization algorithm,nonlinear blind source separation and cross correlation method.Because of the nonlinear relationship between the output signals of capacitance sensors and fluid in pipeline,nonlinear blind source separation is applied.In nonlinear blind source separation,the odd polynomials of higher order are used to fit the nonlinear transformation function,and the mutual information of separation signals is used as the evaluation function.Then the parameters of polynomial and linear separation matrix can be estimated by mutual information of separation signals and particle swarm optimization algorithm,thus the source signals can be separated from the mixed signals.The two-phase flow signals with noise which are obtained from upstream and downstream sensors are respectively processed by nonlinear blind source separation method so that the noise can be effectively removed.Therefore,based on these noise-suppressed signals,the distinct curves of cross correlation function and the transit times are obtained,and then the velocities of two-phase flow can be accurately calculated.Finally,the simulation experimental results are given.The results have proved that this method can meet the measurement requirements of two-phase flow velocity.

Development of capacitive sensor signal conditioning system for angular displacement measurement using timer IC LM555 and UFDC

In this research paper,we have presented variable area type capacitive sensor signal conditioning system for angular displacement measurement and for this purpose we have used timer LM555 based astable multivibrator and universal frequency to digital converter (UFDC). Due to variation in angular displacement in the variable area type capacitor which is connected in the timer based astable circuit,capacitance changes which in turn changes the time period of the timer circuit output. The time period of the timer output waveform is linear with the capacitance and hence linear with angular displacement. The timer output is further processed with UFDC for the measurement. The experimental results show that the time period is linear with the angular displacement in the range of 0- 180° and the uncertainty we should associate it with this average time period value is the standard deviation of the mean,often called the standard error (SE),which is ± 0.023 μs. Because of the simplicity,this measurement system can be used in both electronic and industrial instrumentation.

照明节电调研报告

一、前言 随着城市建设和生产的发展、人民生活的提高,照明用电量也迅速增长。我国照明用电量约占总用电量的7％～8％,个别地区高达15％。宁波市的生活用电量约占13％,且以每年25％～30％的速度不断增长。电能是能源中的“精品”,在目前电力紧张的情况下,重视照明节电具有十分重要的意义。 目前,工厂、企业、商店、宾馆、机关、学校以及家庭中的照明,大多为传统的白炽灯和普通荧光灯,使用节能灯的估计仅1％左右,作为第一代的照明白炽灯,其发光效率仅2％左右,其余98％的电能则以热辐射的形式损失了。作为第二代的普通荧光灯和高压汞灯,其发光效率可达7％～12％,比普通白炽灯高3～6倍。随着科学技术的发展,近几年出现了一种新型的稀土三基色节能灯和用电子镇流器配套的节能型荧光灯,以及大功率低压钠灯和高压钠灯,属第三代灯具,是目前较理想的节能电光源。 节约照明用电,就是要在控制合理、有效的照度和亮度的前提下,提高电能的发光效率,降低照明用电负荷。

Calibration Method of Capacitive Soil Moisture Sensor

Soil properties and water content vary from place to place. The calibration method based on capacitive soil moisture and humidity sensor is carried out. The sensor readings are compared with the mass water content measured by the oven dried method,and the calibration formula of sensor reading and mass moisture content is established.Results show that the sensor reading has a good linear relationship with the mass water content measured by the oven dried method,and has high precision. It can calibrate the mass moisture content of the data obtained from the moisture migration test in the soil column.

Reliability Analysis of Sensor Networks

To Integrate the capacity of sensing, communication, computing, and actuating, one of the compelling technological advances of these years has been the appearance of distributed wireless sensor network (DSN) for information gathering tasks. In order to save the energy, multi-hop routing between the sensor nodes and the sink node is necessary because of limited resource. In addition, the unpredictable conditional factors make the sensor nodes unreliable. In this paper, the reliability of routing designed for sensor network and some dependability issues of DSN, such as MTTF (mean time to failure) and the probability of connectivity between the sensor nodes and the sink node are analyzed. Unfortunately, we could not obtain the accurate result for the arbitrary network topology, which is #P-hard problem. And the reliability analysis of restricted topologies clustering-based is given. The method proposed in this paper will show us a constructive idea about how to place energy-constrained sensor nodes in the network efficiently from the prospective of reliability.

Edge-Weighted Centroidal Voronoi Tessellations

Most existing applications of centroidal Voronoi tessellations(CVTs) lack consideration of the length of the cluster boundaries.In this paper we propose a new model and algorithms to produce segmentations which would minimize the total energy—a sum of the classic CVT energy and the weighted length of cluster boundaries.To distinguish it with the classic CVTs,we call it an Edge-Weighted CVT(EWCVT).The concept of EWCVT is expected to build a mathematical base for all CVT related data classifications with requirement of smoothness of the cluster boundaries.The EWCVT method is easy in implementation,fast in computation,and natural for any number of clusters.

Portable nano probe for micro/nano mechanical scratching and measuring

A nano probe system which can measure precise contact force in mN scale was demonstrated. The nano probe micro parts or optical parts in nanometer range resolution and scratch was originally designed for on-machine measuring applications and one kind of contact type measuring probes was designed for miniaturized or microfactory system. It ideally should be of small size and able to measure surface topography in nanometer scale. A commercial capacitive displacement sensor was proposed. It was a new concept in nano probe systems which can measure the displacement of shaft driven by the variation of surface topography. The nano probe mainly consisted of three parts： a capacitive displacement sensor, a porous type air slide and a contact probe part with various tip radiuses. The porous type air slide assured the shaft slided smoothly with controllable normal force in mN scale and had high positioning accuracy. The probe part which was directly in contact with target surface, can be applied to micro/nanoscale scratching as well as the measurement of sample topography by a simple tip change.

Impact of Sensor Technology for Line Protection Performance

The paper has presented the impact on the line protection performance with the introduction of MUs （merging units） in the process bus level. The paper begins with the introduction on modem digital substation structure and process bus. Then, the paper describes the performances of different sensors such as CTs （current transformers）, CVTs （capacitive voltage transformers）, FOCS （fiber optical current transducers） and FOVS （fiber optical voltage transducers）. With the use of above transducers together with MUs, the performance of distance protection function and line differential protection function have been investigated and presented. Finally, conclusions based on the study are presented in the paper.

Flexible and transparent capacitive pressure sensor with patterned microstructured composite rubber dielectric for wearable touch keyboard application

The development of pressure sensors with highly sensitivity, fast response and facile fabrication technique is desirable for wearable electronics. Here, we successfully fabricated a flexible transparent capacitive pressure sensor based on patterned microstructured silver nanowires(AgNWs)/polydimethylsiloxane(PDMS) composite dielectrics. Compared with the pure PDMS dielectric layer with planar structures, the patterned microstructured sensor exhibits a higher sensitivity(0.831 kPa^-1, <0.5 kPa), a lower detection limit,good stability and durability. The enhanced sensing mechanism about the conductive filler content and the patterned microstructures has also been discussed. A 5×5 sensor array was then fabricated to be used as flexible and transparent wearable touch keyboards systems. The fabricated pressure sensor has great potential in the future electronic skin area.

A new method of rapid quality detection of vacuum insulation panels

A new method of measuring gas pressure in vacuum insulation panels(VIPs)is reported in this study,which provides a fast and efficient quality control option of production.Although there are different methods of measuring gas pressure for VIPs,connecting an internal measurement gauge to external data acquisition units is problematic.The thin high barrier film covering the panel’s core usually prevents external electrical wires or mechanical devices being connected to the inside of the VIPs.To solve this problem,a micro capacitive pressure sensor with 0 to 250 Pa detection range is developed to detect the vacuum pressure.The sensor has high linearity and a sensitivity of 10 mV/Pa.Moreover,through the communication mode study,an ultrasound communications system for VIPs is designed.It shows from operation that this system is stable and reliable,and quick for communication speed.This new method enables the quality detection of VIPs to be completed within 1 second.The minimum detectable pressure of VIPs is below 1 Pa,and the measurement error can be controlled around 5%.