Synchronous topologies

Answer In synchronous topologies, the freewheeling diode of the conventional buck topology is either replaced, or supplanted (in parallel) with an additional mosfet switch. 

As seen in Section 4.1, the major types of losses are the conduction and switching losses. Conduction losses are addressed by selecting a better power switch or rectifier with a lower conduction voltage. The synchronous rectifier can be used to reduce the conduction loss of a rectifier, but it can only be used for forward-mode topologies, and excludes the discontinuous boost-mode converters. The synchronous rectifier will improve the efficiency of a power supply about one to six percent depending upon the average operating duty cycle of the supply. For further improvements, other techniques must be pursued. 

A more robust solution is to introduce a load balancer between die clients and a farm of identical middle tier servers. The load balancer routes requests to one of the middle tier servers based on the load and netweork topology. If one middle tier server fails, it can reroute the request to another to prevent single point of failure (fail-over). This architecture requires that the servers in the middle tier farm synchronize user sessions with each other in case one has to take over a client from another. 

In the scanning mode the electron beam focused on the sample is scanned by a set of deflection coils. Backscat-tered electrons or secondary electrons emitted from the sample are detected. As the electron beam passes over the surface of the sample, variations in composition and topology produce variations in the intensity of the secondary electrons. The raster of the electron beam is synchronized with that of a cathode ray tube, and the detected signal then produces an image on the tube. 

Belykh, I., de Lange, E., and Hasler, M. Synchronization of bursting neurons what matters in the network topology. 

Symmetry or topology For the first time synchronous reactions were theoretically studied by R. B. Woodward and R. Hoffmann on the basis of the orbital symmetry conservation principle formulated by them. This princi-... 

One of the most notable features of the synchronous buck topology is that on decreasing the load, it does not enter discontinuous conduction mode as a diode-based (conventional) regulator would. That is because, unlike a bjt, the current can reverse its direction in a mosfet (i.e. it can flow from drain to source or from source to drain). So the inductor current at any given moment can become negative (flowing away from the load) — and therefore continuous conduction mode is maintained — even if the load current drops to zero (nothing connected across the output terminals of the converter) (see Chapter 1). 

Question 51 How can we implement controlled pulse-skipping in a synchronous buck topology, to further improve the efficiency at light loads ... 

From the preceding discussion we see that, while the general shapes of the Q and T surfaces for the 3 reactions are similar, the condition for a critical point (slopes of Q and -T opposite or equal to zero) and the nature of the critical point (transition state or local maximum) are delicately intertwined and yield a very different topology on the surface that corresponds to the total energy. The critical points on the concerted synchronous pathway for the 2s+2s reaction and the 1,3 dipolar cycloaddition reaction... 

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