Current characteristics

Mass Transport. Probably the most iavestigated physical phenomenon ia an electrode process is mass transfer ia the form of a limiting current. A limiting current density is that which is controlled by reactant supply to the electrode surface and not the appHed electrode potential (42). For a simple analysis usiag the limiting current characteristics of various correlations for flow conditions ia a parallel plate cell, see Reference 43. 

When external secondaiy resistance is used for improved starting charac teristics, short-time-rated resistors are employed. As the motor accelerates, steps of resistance are cut out on a time or current basis to give the desired accelerating torque and current characteristics. 

The spced-torqtie characteristic is the lehitionship between the torque and the speed, in the range from zero to synchronous speed. This relationship, when expressed as a eui ve. w ill include breakdown torque (pull-out torque), pull-up toi que and starting torque. The speed-current characteristic is the relationship of the current to (he speed. 

Figure 12.49 Typical time-current characteristics of 6.6 kV HRC fuses...

Figure 26.3 Time/current characteristics for 11 kV HRC fuses (Courtesy GEC Alsihom)...

Torque, horsepower, and speed requirements demanded in drives for most machines can be met with one of four designs of squirrel-cage polyphase induction motors, Each design offers a different combination of torque, speed, and current characteristics to meet the operating requirements of various industrial applications. 

FIG. 35 Voltage-current characteristics obtained with the setup shown in Figure 33. 

Surface Ionization Sources. In this system, a low ionization potential atom (e.g. caesium) is adsorbed on a high work function metal (e.g. iridium). The temperature is raised so that the rate of desorption exceeds the rate of arrival of the atoms at the surface, and the Cs is then desorped as ions with very small energy spread (< 1 eY). The spot size - current characteristics of these sources lie between liquid metal and plasma discharge sources. 

Typical steady-state voltage-current characteristics in poreforming electrolytes are shown in Fig. 16. A number of authors have attempted to interpret these dependences.103 104 Ebihara et a/.105 used an equation based on a pore model and taking into account a rate-determining transport through the barrier part of... 

John A. Copeland and Stephen Knight, Applications Utilizing Bulk Negative Resistance F.A. Padovani, The Voltage-Current Characteristics of Metal-Semiconductor Contacts P.L. Hower, W.W. Hooper, B.R. Cairns, R.D. Fairman, and D.A. Tremere, The GaAs Field-Effect Transistor Marvin H. White, MOS Transistors... 

Current characteristic of POP levels in background soils are considerably different (Table 1). In some soils their concentrations exceed their permissible levels, which also deviate substantially depending on country and land use. 

Figure 2-2 Ideal and Actual Fuel Cell Voltage/Current Characteristic...

Figure 6-13 Voltage Current Characteristics of a 3kW, Five Cell DIR Stack with 5,016 cm Cells Operating on 80/20% H2/CO2 and Methane (85)...

Figure 8-15 Voltage-Current Characteristics of an AES Cell (1.56 cm Diameter, 50 cm...

The future of the Sun can be read off much better from the printout than from the tea leaves remaining at the bottom of acnp. The Sun s current characteristics, bnt also its past and its future, are all there in the printed matter spewed ont by the computer. 

The power law approximation of the voltage current characteristic for superconductors above Ic has been known for some time (64). Such studies have been made in Y-Ba-Cu-O (65) with results similar to those shown in Figure 16. The value of n in V In has been found to decrease as the magnetic field is increased, and of course becomes ohmic above Hc2. Another representation of the current voltage data is shown in Figure 17 from Enpuku et al. (66), log V vs 1/T for increasing currents (above critical). The expected near straight line arises from the flux creep model of Tinkham for T/Tc 1. 

Cole, K. S., and R. H. Cole, 1941. Dispersion and absorption in dielectrics I. Alternating current characteristics,/. Chem. Phys., 9, 341-351. 

Due to negative voltage-current characteristics of the lamp discharge, a current limiting power supply must be used. 

F. A. Padovani, The Voltage-Current Characteristics of Metal-Semiconductor Contacts... 

Schottky photovoltaic elements were proposed because of the good conformity of the solar spectrum with the polyacetylene forbidden gap. The photovoltaic spectra for (CH)n-Al structure and volt-current characteristic for (CH) -nCdS heterojunction are presented in Fig. 19 and Fig. 20 respectively. 

Figure 19.18. Data of electrochemical fuel cells, (a) Processes in a fuel cell based on the reaction between hydrogen and oxygen, (b) Voltage-current characteristic of a hydrogen-air fuel cell operating at 125°C with phosphoric acid electrolyte [Adlharl, in Energy Technology Handbook (Considine, Ed.), 1977, p. 4.61). (c) Theoretical voltages of fuel cell reactions over a range of temperatures, (d) Major electrochemical systems for fuel cells (Adlharl, in Considine, loc. cit., 1977, p. 4.62).

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