control maintenance and cost of switching

... terminal and a deficiency of electrons at the other When the movement of one coulomb of positive charges or electrons between two points (or the given point of a circuit and the ground) generates J of ... photographs of lab exercises and proofread many parts of the manuscript Other students and postdocs in my lab have also provided numerous corrections and suggestions My former and current department ... purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work Duplication of this publication or parts thereof is permitted only under the provisions of...

Ngày tải lên: 18/02/2014, 22:20

... provide accuracies of g C at room temperature and g C over the full b40 C to a 125 C temperature range Trimming and calibration of the LM50 at the wafer level assure low cost and high accuracy ... applications For example, the cost of a wire-wound platinum RTD tends to be relatively high On the other hand, thin-film RTDs and sensors made from other metals can cost as little as a few dollars ... predictable and therefore correctable Thermistors Another type of resistive sensor is the thermistor Low -cost thermistors often perform simple measurement or trip-point detection functions in low-cost...

Ngày tải lên: 13/12/2013, 05:15

... λB FBG sensor is one of the most attractive optical fiber sensors because Fig Structure of the Fiber Bragg Grating of simplicity in structure and suitability for multiplexed and distributed/multipoint ... one of the promising applications to take advantages of fiber sensors FBGs are sensitive only to the environment experienced along the gauge length of the sensor, typically of the order of – ... 1550 nm output port of the WDM The resolution of the Fig A schematic of the experiment optical spectrum analyzer was 0.06 nm, and the peak wavelength was displayed to the order of 0.001 nm The FBG...

Ngày tải lên: 05/03/2014, 14:20

... temperature of T0.9 The heater in this work is a p+ diffusion resistor and the sensor is a thermopile made up of a series of diffusion/aluminium junctions One of the advantages of this category of sensor ... that the major sources of error are resistor and transistor mismatches, VBE and ΔVBE process variation, VBE non-linearity, op-amp offset and errors due to packaging stress and presents various ... achieves a TC of 100ppm and consumes 200µA from a 4.5-V supply The non-BGR category of references is based on the temperature dependency of mobility and threshold voltages (Vth) of MOS transistors...

Ngày tải lên: 09/09/2015, 11:33

... HEATING/COOLING CONTROL The control output of the TC620 or TC621, either by itself or combined with the low and high set points, forms a simple but flexible temperature controller for environmental and process ... protection is required, the TC620 will control a fan and provide a warning of thermal runaway (Figure 9) The circuit of Figure will turn on the fan at +45°C and give an over-temperature warning ... point The single set point of the TC622 and TC624 has fixed hysteresis of 2°C The push-pull outputs of the TC62X series sensors connect directly to digital logic or microcontroller inputs (see Figure...

Ngày tải lên: 11/01/2016, 11:38

... the pool temperature The complete controller consists of nine low -cost components This, then, energizes the pump when the sun is heating the panels, and turns off the pump when the sky becomes ... headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona in July 1999 and Mountain View, California in March 2002 The Company’s quality system processes and procedures are ... rapid cycling of the controller during partly-cloudy skies, the hysteresis is set for a wide (20°F) span The thermal time constant of the solar panel will also aid in the prevention of rapid pump...

Ngày tải lên: 11/01/2016, 11:38

... sequence of the switching networks is controlled by the control unit, which is, essentially, a digital state machine The voltage detector is used to control the power-up and power-down sequencing of ... measures temperature In addition, the review of the circuitry inside the temperature sensor will provide an understanding of the advantages and disadvantages of silicon sensors as compared to other ... FIGURE 8: Band Gap Voltage Reference Concept A simplified schematic of a band gap circuit is shown in Figure This circuit is based on the principle that the magnitude of currents I1 and I2 are...

Ngày tải lên: 11/01/2016, 14:31

... evaluate and will be used to predict and compare the expected performance of the state variable and relaxation oscillators The RSS analysis consists of listing the magnitude of all the error terms and ... resistors R3 and R4, capacitors C1 and C2 and the RTD resistors R1 and R2 can be minimized by calibrating the oscillator to a single known temperature The magnitude of the resistor and capacitor ... tolerance of 0.01%, TC of ±10 to ±25 ppm/°C and a drift specification of approximately 0.1 to 0.5% RNC90 metal foil resistors are available with a tolerance of 0.01%, temperature coefficient of ±2...

Ngày tải lên: 11/01/2016, 14:35

... headquarters, design and wafer fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California and India The Company’s quality system processes and procedures ... forward currents of IF1 and IF2, and the currents have a ratio of N (IF2/IF1 = N), the difference between the forward voltages (VF) has no dependency on the saturation currents of the two diodes, ... 9, Figure 10 and Figure 11 show an average and ±1 standard deviation of sensor accuracy for the tested parts with the 2nd order error compensation When comparing Figure 9, Figure 10 and Figure...

Ngày tải lên: 11/01/2016, 16:35

... below À40 8C and triclinic between À40 and 20 8C, and another monoclinic between 20 and 325 8C It then changes to an orthorhombic at 325 8C, 469 and succession of tetragonal at 725, 900, and 1225 ... Faculty of Medicine, University of Tokyo in 1982 He enrolled at Graduate School of Medicine, University of Tokyo in 1984 and became a research associate at the Research Center for Advanced Science and ... received his MEng and PhD degrees from University of Tokyo in 1965 and 1968, respectively In 1972, he joined Yokohama National University, and became a professor in 1988 His fields of interest are...

Ngày tải lên: 19/03/2014, 16:47

... chief of the Department of Adhesives and Coatings, vice director of the Department of Sealants and Rubber Composites of Shandong Research Institute of Non-metallic Materials, Committee Member of ... Non-metallic Materials, Committee Member of Chinese Standard of Adhesives and Sealants Now, he is a PhD candidate of materials physics and chemistry of Zhejiang University His research interests include ... and chemistry and polymer materials at Zhejiang University He is currently the director of Reprographic Science and Engineering Society of China and a member of Specialist Group of Polymer Materials...

Ngày tải lên: 19/03/2014, 16:47

... and the PANI/TiO2 thin film prepared at ◦ C has a rough surface and consists of coral-like particulates It is considered that such kind of structure affects the diffusion of gas into and out of ... attributed to C N and C C stretching mode of vibration for the quinonoid and benzenoid units of PANI; 1291 and 1133 cm−1 are the stretching peak of C N and C N, respectively; the peak at 797 cm−1 ... PANI and nano-TiO2 In addition, the absorption band at 1408 cm−1 can be assigned to the in-plane bending vibration of O H on the surface of TiO2 [14] 3.2 UV–vis absorption spectra of PANI and...

Ngày tải lên: 20/03/2014, 13:04

... in physics at University of Science and Technology of Beijing in China (1989) and presently is a professor in Department of Physics of Wuhan University His current fields of interest are Lab on ... of (a) and (b) dielectric loss variation as a function of NH3 concentration at a frequency of 10,000 Hz Fig (a) Capacitance and (b) dielectric loss changes at 10,000 Hz upon exposure to NH3 of ... (1997) and presently is a professor in Department of Physics of Wuhan University His current fields of interest are nanomaterials Guojia Fang received his PhD in physics at Huazhong University of...

Ngày tải lên: 20/03/2014, 13:04

... (approximately, 20 periods) of the sensor response in the presence of the test gas, and the amplitude of the dc component and of the first four harmonics were extracted FFT coefficients of higher harmonics ... coil in the presence of a gas flow of synthetic air (80% N2 and 20% O2 ) introduced from the bottom of the induction coil The surface of the tungsten pellet was oxidised and at the chosen temperature ... evacuation pipe The WO3 films consisted of nanoparticles with a mean grain size of about nm and a log-normal size distribution with a width of about ±20% of the mean size The deposited films were...

Ngày tải lên: 20/03/2014, 13:04

... energies of Fe 2p3/2 and Fe 2p1/2 are 710.7 and 724.3 eV, respectively, which is in well agreement with the literature values of Fe3+ in ␣-Fe2 O3 [25] In Fig 4b, the peaks of Ag 3d5/2 and Ag 3d3/2 ... quantity of polyglycol was added to an aqueous solution of AgNO3 (0.25, 0.5, 1.0, 1.5, 2.0, 3.0 and 5.0 wt%) and Fe(NO3 )3 ·9H2 O The aqueous mixture was then added dropwise to an aqueous solution of ... Ra /Rg , where Ra and Rg are the resistances measured in air and in a test gas, respectively Results and discussion 3.1 Results of characterization Fig shows the TG-DTA curves of as-prepared Ag/FeOOH...

Ngày tải lên: 20/03/2014, 13:04

... Results and discussion 3.1 Crystal structural studies Figs 2(a) and (b) shows the X-ray diffraction patterns of TiO2 and polyaniline films, respectively From Fig 2(a), the presence of broad, small and ... employing a sensitive microbalance The optimized thicknesses of TiO2 and polyaniline films were 0.55 and 0.9 ␮m, respectively, and roughness of the surface was 0.869 ␮m The forward biased junction ... characteristics of the p-polyaniline/n-TiO2 heterojunction in the absence and presence of LPG at room temperature (300 K) Curve (a) in Fig shows the I–V characteristic in the absence of LPG and curves...

Ngày tải lên: 20/03/2014, 13:07

... bundles of monoclinic WO2.72 nanorods with high porosity and little carbon impurities Appl Phys Lett 86, 213105 ͑2005͒ FIG Variation of the magnitude of normalized resistance as a function of measurement ... feedthrough, and by blowing diluted analyte vapor over it with the flow rate of 500 ml/ while monitoring the resistances of the sensing layer and the heater Figure shows the variations of normalized ... for the case of N2 injection with no discernable change, irrespective of reducing and oxidizing analyte gases Their response magnitudes ascend in the order of air, C2H5OH, NH3, and NO2 exposures,...

Ngày tải lên: 20/03/2014, 13:07

... bundles of monoclinic WO2.72 nanorods with high porosity and little carbon impurities Appl Phys Lett 86, 213105 ͑2005͒ FIG Variation of the magnitude of normalized resistance as a function of measurement ... feedthrough, and by blowing diluted analyte vapor over it with the flow rate of 500 ml/ while monitoring the resistances of the sensing layer and the heater Figure shows the variations of normalized ... for the case of N2 injection with no discernable change, irrespective of reducing and oxidizing analyte gases Their response magnitudes ascend in the order of air, C2H5OH, NH3, and NO2 exposures,...

Ngày tải lên: 20/03/2014, 13:07

... surface of the grains constituting the sensitive layer on the one hand and the electronic transport mechanisms in and between the grains on the other hand M Bendahan et al / Sensors and Actuators ... used in the conduction model where N and N* = Nmax − N are the densities of occupied and free adsorption sites, respectively, and [O2 ] and [O3 ] the oxygen and ozone concentrations This equation ... band and surface states The conductance of the SnO2 layer can then be expressed in a function of the potential barrier (Vs) [14] Nevertheless, this equation is available for a porous layer and...

Ngày tải lên: 20/03/2014, 13:12

... the diffraction angle range 20◦ ≤ 2θ ≤ 60◦ , with a step width of 0.05◦ and a step time of s The composition and oxidizing state of the thin films were investigated using X-ray photoelectron spectroscopy ... with a volume of 0.18 m3 and kept under a continuous flow of fresh air for 10 before measurement The operating voltage (VH ) was supplied to either of the coils for heating the sensors and the circuit ... peak of O 1s is found to lie at 530.2 eV, and is assigned to lattice oxygen in the WO3 crystal As shown in Fig 2(c), the photoelectron peaks of W 4f5/2 and W 4f7/2 are found to lie at 37.1 and...

Ngày tải lên: 20/03/2014, 13:12