Current tap

Figure 9 Voltage vs current and onset of resistance above the critical current for (A) "ideal case", (B) premature thermal runaway, (C) damaged sample, and (D) inadequate current transfer length between voltage and current taps as discussed for low temperature superconductors. Ref. 26.

Metal-oxide electrodes are usually manufactured as metallic plates or wires with a current tap immersed in a saturated solution of the corresponding oxide in the melt studied. The potential of such an electrode can be calculated from the standard electrode potential in the melts. The activity of the metal cations in the saturated solution is determined in the following manner ... 

Characteristic features of the construction of the reference electrodes mentioned consist in the materials serving as current taps. Platinum is used with silver reference electrodes, but cannot be used for lead electrodes since the lead forms alloys with Pt and the current taps are destroyed by such interactions. This requires the use of iron or tungsten wires as intermediate current-tap materials. The potentials of the mentioned reference electrodes are highly reproducible, and they were extensively and thoroughly studied over a wide range of temperatures and concentrations in potentiometric cells of the following kinds ... 

Carbon electrodes are usually cycled in aqueous solutions in the potential range from 0 to 1V (RHE, reversible hydrogen electrode). Herewith, as pointed out above, average values of specific capacitance of not more than 200 F/g are usually obtained. The lower limit of potentials is because of hydrogen evolution on metallic current taps and the upper limit is related to the oxidative corrosion of carbon. ACs were used in our work of Volfkovich et al. (2012) in studies of electrodes based on AC ADG... 

The separator used was a Nation membrane. Each electrode was separated by a carbon paper disk (Toray TGP-H-090) from the Ti plate current tap to minimize contact resistance. The assembled cell was immersed into 1M H2S04(aq) to impregnate electrodes by electrolyte. 

Figure 29.1. Schematic drawing of the HSC device of the C-Pb02 type. (1) casing, (2) insulator, (3) current tap of the negative electrode, (4) negative electrode, (5) positive electrode, (6) porous separator, and (7) sealant.

The Number of taps sets the number of delayed signals that will be returned as echoes. As you move the slider to add more taps, the numbers on the Current tap list become active one by one. All of the controls below this list apply to whichever Current tap is selected to modify the third tap, make sure at least three taps are available and then select the radio button before the 3. Taps appear on the graph as lines, with the active Tap being red. 

Fig. 10. The Groth ZG 5 centrifuge. R, rotor R, stationary shaft T, Teflon seal K, K, chambers for gas scoops S, S2, scoops V, gas supply M, manometer Z, Z2, tapping points for enriched and depleted gas P, P2, vacuum chambers E, electromagnet for eddy current heating Tb, Tb2, temperature measuring devices K, cooling coil and D, D2, labyrinth seals.

Generalizing the above equation, autotransformer tapping for a particular starting current, /at >s... 

From this equation, the desired tapping of the auto-transformer, to limit the starting current to a desired value can be determined. 

A squirrel cage motor has its 4, on DOL as six times its rated current. Find the required tapping on an autotransformer to limit the starting current to 1.5 times. 

Star contactor C and A/Tcontactor Ci must be rated for the square of the percentage lapping. For a tapping of 80%., for instance, the rating of the contactors C and Ci will be (0.8) or 64% of the full-load current of the motor. The main contactor Ct, however, will be rated for the full-load current. 

For a 3.3 kV 450 kW motor, with a full-load current of 100 A and starting current on DOL as six times the rated current, the kVA rating of the transformer for 50% tapping will be... 

Through the tap-offs of the bus, the unit auxiliary transformers (UATs) are connected to feed the station auxiliary services. For more clarity we have taken out the portion of the tap-offs from Figure 13.21 and redrawn it in Figure 13.18 to illustrate the above system and its interconnections. The tap-offs are now subject to the cumulative inOuence of the two supply sources. In the event of a fault on this section, both the sources would feed the same and the fault current through the tap-offs would add up. The tap-offs should thus be designed for the cumulative effect of both fault levels. For the sake of an easy reference, Table 13.8 suggests a few typical values of fault currents, worked out on the basis of data considered for the G and GT. One such example is also worked out in Example 13.3. 

For the tap-offs, connecting a UAT through the main bus section between the generator and the generator transformer, however, as discussed above, the momentary peak current will depend upon the short-time rating of such tap-offs. The likely ratings are noted in Table 13.8. 

In single-phase bridge circuits for ac connections and for very low ac output voltages below 5 V, single-phase center tap circuits are used as rectifier circuits for CP transformer-rectifiers. They have an efficiency of 60 to 15% and a residual ripple of 48% with a frequency of 100 Hz. A three-phase bridge circuit for three-phase alternating current is more economical for outputs of about 2 kW. It has an efficiency of about 80 to 90% and a residual ripple of 4% with a frequency of 300 Hz. The residual ripple is not significant in the electrochemical effect of the protection current so that both circuits are equally valid. 

Fit up the apparatus shown in Fig. 64. It consists of a large wide-necked bottle, in which the ammonia solution is placed The solution is stirred by a mechanical stirrer, rotated by means of a water-turbine. The solution of the chloracetic acid in 50 c.c. water, is dropped in from a tap-funnel. After standing 24 hours the liquid is poured into a flask, and the C lcess of ammonia is removed by passing in a current of steam, and evaporating at the same time on the water-bath until the last traces of ammonia disappear. The solution now contains gly-... 

Brainstorming is a free-form process that taps into the creative potential of a group through association of ideas. Association works as a two-way current when a group member voices an idea, this stimulates ideas from others, which in turn leads to more ideas from the one who initiated the idea. 

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