Resonant topology

As one can see, there is the familiar choke input filter (T-C) on the output, which is characteristic of the buck and all forward-mode converters. The configuration shown in Figure 4—10 is called a parallel resonant topology because the load impedance (the T-C filter acting as a damping impedance) is placed in parallel to the resonant capacitor. The input to the T-C filter stage... 

Figure 4-12 Nontransformer-isolated quasi-resonant topologies.

This design example is the PWM design example (Section 3.15.4), modified to a quasi-resonant topology. Please refer to Figure 4-25. 

Then there are also some other types of LC-based possibilities — in particular the resonant topologies. ... 

M. Gordon and W. H. T. Davison, Theory of resonance topology of fuUy aromatic hydrocarbons, J. Chem. Phys. 20 (1952) 428-435. 

A large number of compounds in which nitrogen is (formally) singly or doubly bonded to a nonmetallic heteroelement have been studied in N or resonance. Topologic, electronic, and steric contributions to and shielding relationships in the P(III)-N bond have been deduced from aminophosphine studies, and for amine-boranes, correlations observed of and "B with C in the... 

Quasi-resonant converters force the voltage or current waveform into a haver-sine waveshape. If the power switch(es) are switched at the right moments, then there are no switching losses experienced. Also because of the controlled rates of change for the voltage or current waveforms, much better RFI/EMI performance is realized. Most of the basic topologies that exist within the PWM family are also in the quasi-resonant family. 

The zero current switching (ZCS) quasi-resonant (QR) switching power supply forces the current through the power switch to be sinusoidal. The transistor is always switched when the current through the power switch is zero. To understand the operation of a ZCS QR switching power supply, it is best to study in detail the operation of its most elementary topology—the ZCS QR buck converter (and its waveforms) as seen in Figure 4-10. 

ZVS QR topologies appear to be the more popular of two methods of quasi-resonant technologies. This is mainly due to two reasons first, its typical variation in frequency over its input and load variations is 4 f as opposed to fO f for the ZCS topologies secondly, it has a better heavy load performance. Also, some of the more troublesome parasitic elements within the circuit can be more easily harnessed. 

Quasi-resonant Switching Power Supply Topologies... 

As with PWM switching power supplies, there are comparable topologies within the zero-current switching (ZCS) and zero-voltage switching (ZVS) quasi-resonant families. You ll immediately recognize the family members upon seeing them. 

BalK82 Balasubramanian, K. Topological and group theoretical analysis of dynamics nuclear magnetic resonance spectroscopy. J. Phys. Chem. 86 (1982) 4668-4674. 

The concept of relative hardness and topological resonance energy per electron as a measure of aromaticity, with a relative hardness value of zero as the border for antiaromaticity, failed for 1-benzothiepin,3 2... 

The refinement of other analytical methods, such as electrophoresis [34,36], the various techniques of optical spectroscopy [103-105], and nuclear magnetic resonance [201], is supplemented by the recent advances in real-time affinity measurements [152,202], contributing to the understanding of biomolecular reactivity. Taken together, the improvement of analytical methods will eventually allow a comprehensive characterization of the structure, topology, and properties of the nucleic acid-based supramolecular components under consideration for distinctive applications in nanobiotechnology. 

Porphyrin is a multi-detectable molecule, that is, a number of its properties are detectable by many physical methods. Not only the most popular nuclear magnetic resonance and light absorption and emission spectroscopic methods, but also the electron spin resonance method for paramagnetic metallopor-phyrins and Mossbauer spectroscopy for iron and tin porphyrins are frequently used to estimate the electronic structure of porphyrins. By using these multi-detectable properties of the porphyrins of CPOs, a novel physical phenomenon is expected to be found. In particular, the topology of the cyclic shape is an ideal one-dimensional state of the materials used in quantum physics [ 16]. The concept of aromaticity found in fuUerenes, spherical aromaticity, will be revised using TT-conjugated CPOs [17]. 

---