Inductor inductance value

It was observed by Gopala Rao and Sastri that the reaction between hydro-quinone and chromic acid leads to the induced oxidation of oxalic acid, glycerol, lactic acid, glucose, citric acid, and malic acid. If the concentrations of the above acceptors are cen times that of that of the hydroquinone inductor, the values of F found are, respectively, 0.51,0.46,0.35,0.27 and 0.17. The numerical values of the induction factor do not permit us to discuss the nature of coupling intermediate. 

The permeability is also affected by stress the induced change decays logarithmically with time as a form of disaccommodation. Inductors are usually made in two parts so that the winding can be introduced on a bobbin the parts must then be joined closely together to prevent the permeability from being affected by an uncontrolled air gap. If a mechanical clamp is used, the force must not be excessive and must be the same in similar units. Its effect must be allowed to decay before the inductance value is finally adjusted. 

Multilayer technology is exploited just as for multilayer capacitors (see Section 5.4.3) to EIA size specifications, and inductor chips can be bandoliered ready for surface mounting, typical inductance values lying in the range 1 nH to about 20 /rH. They find important applications as EMI suppressors as well as for a wide range of applications as a lumped circuit component in equipment of all types -communications, entertainment , computers, etc. (see Fig. 9.17). 

An inductor is commonly a coiled conducting wire wrapped around a core (e g., ferromagnetic material) with two terminals. When current passes through the inductor, magnetic flux is produced, resulting in inductance. The number of loops, the size of each loop, and the core material all affect the inductance value. 

The ferrite inductors are shaped as pot cores. Fig. 5.7, formed of two matching halves. The central part is shorter than the outer surfaces when they are in contact, a gap appears in the centre of the device. This central part has a hole, such that a magnetic rod can be inserted into it, in an adjustable position. An adjustable gap is quite useful in pot cores in addition to allowing a fine calibration of the final inductance value of the device, it decreases its temperature sensitivity and increases the working frequency. The presence of a gap leads to a lower permeability value because a demagnetising field is generated, decreasing the value of the total applied field ... 

Ferrite thin films can be included in integrated circuits where an inductor is required. A metallic coil is deposited on an epitaxial YIG film by sputtering, with a meander pattern. To increase the effective inductance value, a second ferrite film is placed on top of the coil, in a sandwich configuration (Arai et al, 1991). Plating techniques (see Section 3.6.3) have also been used to deposit ferrite thin films on GaAs integrated circuits (Abe et al, 1988). 

In the non-actuated state of the actuator, the inductor represents a high impedance state which translates into a high inductance value. When the bridges are actuated, the contact pads make a DC short with the transmission lines, leading to low impedance and in turn a low inductance state. The inductors were measured in the frequency range of 1-30 GHz in the same setup as that of the RF switches. Figure 12.18 shows the insertion loss and the return loss of the tunable inductor in the non-actuated and the actuated state of the diamond bridge. 

Table 2 Electrical performances, i.e., maximum Q factor (Qmax) and resonance frequency (Q of coplanar spiral inductors on p-type mesoporous silicon (except for Capelle et al. 2011). All the dimensions are in microns. The inductance value L is determined for low frequencies (f 0)... 

Planar inductors are suited for both thick-film, thin-film, and LTCC applications. Typical members of this group are meander and spiral inductors (Figure 9.22). Meander inductors offer the lowest inductance vs. size. Their inductance value is determined by tiie length and the unit line inductance. Because of the adverse magnetic-field orientation of adjacent line segments, there is no increase of the overall inductance [6]. The inductance is directly proportional to the meander lengtii. Meander inductors are usually used for low inductances and delay lines. Because the meander is more or less a transmission line, the distributed character is dominating in most cases. 

Groxond planes under spiral coils reduce the inductance values. This effect is taken into accoxmt by applying the image-current method (Figure 9.26). A second coil with identical dimensions but opposite current flow is located under the spiral inductor with a spacing of twice the groxmd-plane distance h. The full set of equations can be found in Reference 31. 

The existence of a groimd plane reduces the inductance values of three-dimensional inductors as well. This can be verified by measurements [35]. Figure 9.32 shows the inductance vs. height-above-groxmd for a rectangular... 

Calculated and ( ) measured inductance values for rectangular spiral inductors vs. number of... 

Ideal inductors act as a pure reactance directly proportional to the frequency (Equation 9.32). They cause a current-voltage shift of 90° in an electrical circuit. The inductance value is influenced by design and material parameters as described earlier. 

Lumped inductors in series connection are usually described by the n model as shown in Figure 9.59. The shunt capacitors depict the parasitic capacitances of coil windings to ground. Capacitive coupling between windings cause the self-resonance frequency /, as shown in Equation 9.38. Because of increasing effective inductance values in the vicinity of a parallel resonance, the inductors can only be used far below the self-resonance frequency (Figure 9.60). 

Two frequency ranges are of interest in inductor characterization. The low range from kHz to about 100 MHz is dominated by the skin effect. The inner self-inductance virtually drops down to zero. The inductance value determined at high frequencies differs considerably from the value measured at a low frequency (Figure 9.63). The inner self-inductance is reduced by the square root of the frequency. Wider lines show a more significant inductance drop [35] compared to smaller lines. 

S-parameters of an inductor with (a) lumped, (b) distributed behavior (both inductors have the same inductance value of 9.6 nH). 

Tlte value of / can thus be varied in magnitude and phase displacement to suit a particular location of installation or pi otective scheme by introducing suitable R and /Y into the neutral circuit. When the impedance is inductive, the fault current will also be inductive and will offset the ground capacitive current /". In such a grounding, the main purpose is to offset the fault current as much is possible to immunize the system from the ha/ai ds of an arcing ground. This is achieved by providing an inductor coil, also known as an arc suppression coil, of a suitable value in the neutral circuit. 

Real world values do not allow a capacitor of this large a value. The largest value capacitor that will pass the ac leakage current test is 0.05 pF. This is 50 percent of the calculated capacitor value, so the inductor must be increased 200 percent in order to maintain the same corner frequency. The inductance then becomes 900 pH and the resultant damping factor is 2.5 which is acceptable. The resulting schematic is shown in Figure 3-77. 

Coupled reactions occur when the primary reaction results in an intermediate which enables the acceptor to react too. The main characteristic of this reaction is that the value of the induction factor is small, not exceeding 2 even under most favourable conditions for the induced change. Plotting F-, against the ratio of the initial concentrations of acceptor and inductor results in a curve having a limiting value. 

Thus, Ip (inductor peroxide, primary oxide) derived from I d is converted by Ac d into the end-product, I(,x, which is inactive regarding the induction, i.e. coupling cannot turn into catalysis. Moreover, since there are several consecutive steps, and since the direct reaction between actor and acceptor is very slow, it follows that the value of Fj will not be changed by altering the ratio, ([Ac]/[I])o. However, in most cases studied the function Fj = /(Ac/I)q attains a limiting value, or at least varies therefore it has to be concluded that Manchot s concept cannot be maintained in its original form. 

The stoichiometry of the induced reaction depends, as in the Fe(II)-S20 system, on the iron(II)/iron(III) ratio and on the pH. Therefore, it can be expected that under identical experimental conditions (actor, inductor, and hydrogen ion concentration) the induction factors for the two systems should be identical. The data obtained show that this expectation is fulfilled. For the photo-induced oxidation of arsenic(III) the value of ks /k -j was found to be 2, while in the present system k Jk -j = 4. (Comparing these values with the value of k jk = 21, it can be concluded that the SO4 radical, formed by reaction (43), is not removed by the reaction... 

Author s Comments That s obviously not true. The customer has had problems at 1A load too. So this explanation, even if true (and it is not) does not really fit the set of clues provided by the customer. It could be one reason, but is not the explanation. As indicated previously, the saturation rating of most inductors is not a cliff over which you suddenly fall off into a timeless abyss. Saturation usually just means the inductance has fallen by about 20 to 30% from its initial value. So in going further, say from 3A to 3.5A, you can expect the inductance to fall to about 50% of its initial value. But rarely any more For sure, it doesn t suddenly morph into a resistor. ... 

The inductor model is used to specify inductor voltage dependence. The value of the inductance used in the simulation is ... 

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