Volt-amperes

Fig. 10. Power factor at 1 MHz vs temperature for some commercial glasses. Courtesy of Corning Inc. The power factor is the ratio of the power ia watts dissipated ia a material to the product of the effective siausoidal voltage and current ia volt-amperes. When the dissipation factor is less than 0.1, the power...

The operation of switehing power supplies ean be relatively easy to understand. Unlike linear regulators whieh operate the power transistor in the linear mode, the PWM switehing power supply operates the power transistors in both the saturated and eutoff states. In these states, the volt-ampere produet aeross the power transistor is always kept low (saturated, low-U/high-/ and eutoff, Hi-T/No-T). This El produet within the power deviee is the loss within all the power semieonduetors. 

We shall note that there are numerous experimental papers dealing with studies of effect of adsorption on other electrophysical characteristics of oxide adsorbents such as thermal electromotive force [107], Hall effect [108 - 110], volt-ampere [58, 111] and frequency [112] characteristics. The availability of results of these studies makes one expect that in near future the adequate theoretical model describing adsorption-induced changes in electrophysical characteristics of semiconductor adsorbent will be developed. 

The adsorption-induced charging of the barriers of such adsorbents results in the change in heights of inter-crystalline barriers and transforms the profile of their distribution function. As the model suggests, it is this change in the distribution function of the heights of barriers, that is responsible for adsorption-induced change of such an important characteristic of polycrystal as the differential coefficients of its volt-ampere characteristics or, which is more convenient for our studies,... 

An absolutely different situation occurs in case of polycrystalline adsorbent treated at high temperature in air or in other oxygen containing medium. In this case the volt-ampere analysis exhibits sharply nonlinear VAC, deviations from the Ohm law being observed at anomalously low fields [47]. This indicates an existence of high intracrystalline barriers in such adsorbents. These barriers can be attributed to crys-... 

Fig. 5.21. Volt - ampere characteristic of the secondary election collector with the Au/ZnO film being acted upon by helium metastable atoms of different concentration (d) and neon (/) metastable atoms (2) (6) [164]...

In most plants the only areas that are air-conditioned are the offices, laboratories, and control rooms. For offices, 3-6 volt amperes/ft2 (32-65 volt amperes/m2) is a typical load.46 For control rooms the load will be somewhat higher, and for laboratories, because of increased ventilation requirements, it may be much higher. 

Figure 2. Volt - amperic curves of an air-Al cell with NaCl solution at 20°C.

The term voltammetiy may be contrasted with a term such as potentiometiy. Of course, the use of volt comes from Volta, who in 1800 reported die first electric battery. In a similar way. one refers to amps as a measurement of current because of the very early work of Ampere on electrical circuits. The trend now is to use the generic term (potential, current) instead of the historical one (volt, ampere). 

The direct-current (DC) volt-ampere (V-A) characteristics were measured with a microcomputer-controlled Keithley 617 electrometer in the temperature range 10 to 60 °C. From linear part of V-A dependences the resistance ffl - U/I was determined [32], where U is the voltage on the needle electrodes and I is the current passing through the sample. 

The common relationship between volts ( ), amperes (/), and resistance (R) is known as Ohm s law... 

Power (Electrical) The rate at which energy is transferred. A volt ampere, an electric measurement unit of power, is equal to the product of one volt and one ampere. This is equivalent to one watt for a direct... 

Treatment of Na2[IrCl6] with KOH under strictly defined conditions has yielded red K2[Ir(OH)6], this novel species being characterized from thermogravimetric analyses, volt-ampere curves, and absorption spectra.253... 

Figure 2. Volt-ampere curves of pure LaMm sample and with additives.

Combination of the mechanical system with electric phenomena requires an additional base quantity of an electrical nature. As such the Ampere has been chosen as basic unit. The derived unit of electrical energy, the Joule (= Volt Ampere second = Watt second) is equal to and identical with the unit of mechanical energy, the N m ... 

It is customary that electrical parameters be given in terms of practical units (volts, amperes, coulombs, etc.), so conversion factors are required. Practical units are used so that the numbers usually encountered will have values which are not extremely large or small. See App. D for a more complete discussion of electrical units. 

Figure 21. Schematic volt-ampere characteristic curve for a semiconductor diode...

The computational model operates by specifying a value for J, the output current density, which specifies a position on the volt-ampere characteristic. The output voltage, Vq, is the value to be calculated. 

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