Ferro-resonance effects

R Damping resistor to prevent ferro-resonance effects Figure 15.7 Equivalent circuit diagram of a CVT... 

This may become higher, depending upon the circuit s conditions (for example, the ferro-resonance effect, Section 20.2.1.2). 

Now the situation is different, as resonance and ferro-rcsonance effects in the series inductive-capacitive circuits may cause dangerous overvoltages. 

The phenomenon of saturation of the magnetic core of such a device during normal operation and its resonance with the ground capacitive reactance, X. , is known as ferro-resonance. It would have the same effect on the healthy phase,s/system as in (i) above. 

The carbonyl stretching frequencies of a number of heteroannular ferro-cenecarboxylic acids have been measured (41). The spectral shifts vary in the direction expected from the electronic effects of the substituent groups, and parallel the effects of these substituents on the acid constants. Little and Clark have also demonstrated resonance interaction of the ferrocenyl group in ferro-cenylazobenzenes by measuring shifts in the absorption maxima in the visible and ultraviolet spectra (49). 

In mixed solutions of ferro- and ferri-cytochrome c cross saturation effects could be observed by this technique. For example when the methyl resonance at +23.2 ppm of ferricytochrome c (Fig. 19) was irradiated, saturation effects were also observed in the methyl resonance of ferro-cytochrome c at +3.3 ppm (Fig. 27). This cross relaxation was shown to arise from an exchange of protein molecules, and hence also the saturated spins, between the ferrous and ferric oxidation states. The life-time in either oxidation state then has to be comparable to or shorter than the longitudinal spin relaxation time of the observed protons. Besides... 

Resonance enhancement effects for the NNSS and NNS lines are not so pronounced as for the ferro line (see next section). Intensity variations of about a factor of 10 are observed for El in the range 1.95[Pg.248]

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