Resistor properties

Morris, L., Williams, D.E., Kaltsoyaimis, N., and Tocher, D.A. Surface grafting as route to modifying the gas-sensitive resistor properties of semiconducting oxides studies ofRu-graftedSn02./ Jjyj. Chem. Chem. Phys. 2001,3,132-145. 

Several kinds of conduction mechanisms are operative in ceramic thermistors, resistors, varistors, and chemical sensors. Negative temperature coefficient (NTC) thermistors make use of the semiconducting properties of heavily doped transition metal oxides such as n-ty e Ti O andp-ty e... 

Miscellaneous. Ruthenium dioxide-based thick-film resistors have been used as secondary thermometers below I K (92). Ruthenium dioxide-coated anodes ate the most widely used anode for chlorine production (93). Ruthenium(IV) oxide and other compounds ate used in the electronics industry as resistor material in apphcations where thick-film technology is used to print electrical circuits (94) (see Electronic materials). Ruthenium electroplate has similar properties to those of rhodium, but is much less expensive. Electrolytes used for mthenium electroplating (95) include [Ru2Clg(OH2)2N] Na2[Ru(N02)4(N0)0H] [13859-66-0] and (NH 2P uds(NO)] [13820-58-1], Several photocatalytic cycles that generate... 

Nonferrous alloys account for only about 2 wt % of the total chromium used ia the United States. Nonetheless, some of these appHcations are unique and constitute a vital role for chromium. Eor example, ia high temperature materials, chromium ia amounts of 15—30 wt % confers corrosion and oxidation resistance on the nickel-base and cobalt-base superaHoys used ia jet engines the familiar electrical resistance heating elements are made of Ni-Cr alloy and a variety of Ee-Ni and Ni-based alloys used ia a diverse array of appHcations, especially for nuclear reactors, depend on chromium for oxidation and corrosion resistance. Evaporated, amorphous, thin-film resistors based on Ni-Cr with A1 additions have the advantageous property of a near-2ero temperature coefficient of resistance (58). 

The silver white, shiny, metal-like semiconductor is considered a semimetal. The atomic weight is greater than that of the following neighbor (iodine), because tellurium isotopes are neutron-rich (compare Ar/K). Its main use is in alloys, as the addition of small amounts considerably improves properties such as hardness and corrosion resistance. New applications of tellurium include optoelectronics (lasers), electrical resistors, thermoelectric elements (a current gives rise to a temperature gradient), photocopier drums, infrared cameras, and solar cells. Tellurium accelerates the vulcanization of rubber. 

Due also to their (amorphous) composition, the heat capacity of a ruthenium oxide resistor is much higher than that of a Ge thermistor of equal mass [61]. This negative property prevents the use of Ru02 resistors as detector sensors (see Chapter 15). 

Using nitrile oxides, various compounds and materials possessing valuable properties have been prepared. Among them are thin-film resistors useful for a thermal head and comprising a nitrile oxide, ruthenium and oxygen, a method for manufacturing the resistor by coating or deposition (529), isoxazole and/or isoxazoline polyheterocyclic systems like 458, which are useful for development of a new class of ionophores (530). 

The field emission properties of carbon nanotube forests and single nanotubes are described. Controlled emission is possible for aligned CNT arrays where the spacing is twice the CNT height, as grown by plasma enhanced chemical vapor deposition. This leads to the maximum field enhancement factor. For random forests, the field enhancement obeys an exponential distribution, leading to a lower emission site density and imperfect current sharing. Ballast resistors can help alleviate this problem. Random nanocarbons perform less well than CNTs. Some applications are covered. Elec-... 

EIS data is generally interpreted based on defining an appropriate equivalent circuit model that best fits the acquired data. The elements of the circuit model involve a specific arrangement of resistors, capacitors, and inductors that tacitly represent the physicochemical reality of the device under test. Under these circumstances the numerical value for chemical properties of the system can be extracted by fitting the data to the equivalent circuit model. Impedance measurements are typically described by one of two models ... 

Beryllium oxide shows excellent thermal conductivity, resistance to thermal shock, and high electrical resistance. Also, it is unreactive to most chemicals. Because of these properties the compound has several applications. It is used to make refractory crucible materials and precision resistor cores as a reflector in nuclear power reactors in microwave energy windows and as an additive to glass, ceramics and plastics. 

There are several ways to change the properties of parts. Some have already been illustrated previously, but we will now go over all of the different methods. The first thing we need to do is to select a part. We will select resistor R1. Place the... 

Resistor R1 is highlighted in pink and enclosed in a dashed box, indicating that it is selected. To edit all of the selected item s properties at the same time, click the LEFT mouse button on the Edit menu selection and then select Properties ... 

The Part Reference property is the name of the resistor, Rl in this case. The PCB Footprint property is the graphic that will be used if you use this schematic to create a PC board. If we scroll the window to the right, we will see more properties. Two screen captures are shown below to display all of the properties ... 

The value of the PSpICe Template property generates the PSpice netlist line for the resistor when you create a netlist for the schematic. The TC property is a temperature coefficient for the resistor. Its default is zero (no temperature dependence). The property Value is the value of the resistor in ohms. The Source Library (not shown in the screen captures above) is the name of the. olb file in which the part is located. 

If you remember, the footprint of the resistor was not shown on the schematic. This is because the PCB Footprint property is not being displayed. All properties can either be displayed or not. We will illustrate how to display the PCB FOOtp/Int property. Scroll the properties window to the left to display the PCB Footprint property and then click the LEFT mouse button on the PCB Footprint column to select the column ... 

The second way to edit a part s properties is to double-click the LEFT mouse button on the graphic symbol for that part. To edit the properties of R2, double-click the LEFT mouse button on the R2 resistor graphic, +AVV-. Make sure that you click on the center of the graphic. If you double-click fast enough, the properties spreadsheet will appear ... 

The Performance Analysis capabilities of Probe are used to view properties of waveforms that are not easily described. Examples are amplifier bandwidth, rise time, and overshoot. To calculate the bandwidth of a circuit, you must find the maximum gain, and then find the frequency where the gain is down by 3 dB. To calculate rise time, you must find the 10% and 90% points, and then find the time difference between the points. The Performance Analysis gives us the capability to plot these properties versus a parameter or device tolerances. Hie Performance Analysis is used in conjunction with the Parametric Sweep to see how the properties vary versus a parameter. The Performance Analysis is used in conjunction with the Monte Carlo analysis to see how the properties vary with device tolerances. In this section we will plot the bandwidth of an amplifier versus the value of the feedback resistor. See Sections 9.B.3 and 9.E to see how to use the Performance Analysis in conjunction with the Monte Carlo analysis. 

Electroceramics. Titanates like barium, strontium, calcium and lead titanate prepared from finely divided, high-purity TiOz hydrolysates are used in capacitors, PTC-resistors and piezoelectric materials. The specifications of the Ti02 starting materials with respect to purity, reactivity, and sintering properties are expected to become more stringent. The market is estimated to be several thousand of tonnes a year as TiOz. A strong annual growth is expected. 

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