Half-bridge converter

Figure 3-77 Schematic of a 100 kHz, 280W, half-bridge converter.

A Zero Voltage Switched Quasi-resonant Off-line Half-bridge Converter... 

This converter is intended to function as a bulk power supply for a distributed system. It has only one +28VDC output at 10 A. This is going to be a classic ZVS quasi-resonant half-bridge converter that is, variable frequency, voltagemode controlled with averaging overcurrent protection. It is representative of the designs using the available control ICs on the market today. 

FIGURE 10.85 (a) Push-pull converter, (b) half-bridge converter, (c) full-bridge converter. Coupling capacitor Cc is... 

Only one smoothing capacitor is required at the input for this configuration (Fig. 10.85(c)) and for the same transistor type as that of half-bridge, output power can be doubled. Usually used for power levels above 1 kW, the design is more costly due to increased number of components (uses four transistors compared to two in push-pull and half-bridge converters.)... 

Any Buck-derived topology (e.g., the Forward converter, the Half-Bridge, the Push-Pull, the Full-Bridge, etc.) needs an output choke. Otherwise it is akin to running a Buck without its inductor—you can thereby create a dead short cross the input supply rails. 

The previous section considers a simple DC to DC boost converter with two switches controlled by two complementary signals. The healthy boost converter thus may be in one of two feasible modes. Reference [18] studies switch faults in a simple single phase half-bridge inverter. In [17], bond graph-based FDI is applied to a single phase H-bridge inverter. Both works represent switches by means of controlled junctions, i.e. use hybrid bond graphs. 

Usually, for power levels above 300 W, double-ended converters are used. Full-wave rectifiers are used in the double-ended converters and the ripple frequency of the output voltage is twice the switching frequency. Three important double-ended PWM converter configurations are push-pull (Fig. 10.85(a)), half-bridge... 

Steigerwald, R.L. 1988. A comparison of half-bridge resonant converter topologies. IEEE Trans, on Power Electronics PE-3(2) 174-182. 

Topologies often vary based on control scheme, switch rating, component count, and circuit complexity. While various topologies have been compared and presented in the literature, the robust buck-boost (half-bridge) DC-DC converter remains the most popular for use in hybrid battery-supercapacitor systems as a result of its simplicity and efficiency. 

The A and B peptide chains in insulin are linked through disulfide bridges. Their presence was suspected from the change in molecular weight which followed the reduction of insulin. For quantitative analyses the S-S bridges had to be broken. Sanger, following the approach used by Toennies and Homiller (1942), oxidized the protein with performic acid, so that the half-cystines were converted to cysteic acid. After oxidation, insulin could be separated into its A and B chains, the A peptide with 20 amino acid residues and the B with 30. 

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