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DC converters

Efficiency is one of the central concepts in DC converters. As with any technical device, the efficiency of a DC converter describes the relationship between work and performance. From the electrician's point of view, this is the relationship between output voltage and current of the DC converter and input voltage and current. Depending on the construction method, unregulated DC converters usually have an efficiency of 70-90%, while regulated DC converters have an efficiency of 70-85%.

DC converters with linear regulators have a rather meagre efficiency of 50-70%, while regulated DC converters with feedback (input-side switching) may reach 90%. This shows that regulation in a DC converter always involves some power loss to keep active under any operational circumstances. This becomes particularly clear when you run a DC converter without output load; the electrical uptake at the input side is significantly higher than in an unregulated DC converter in the same output class.

The efficiency can be increased using specifically selected components such as MOSFETs instead of bipolar transistors or Shottky diodes instead of silicon diodes; the latter is usually used in unregulated DC converters. However, using completely different switching techniques such as synchronous rectification instead of diodes is a method particularly suitable for regulated CD converters, especially for more high-performance modules. Increasing DC converter efficiency raises the maximum operating temperature of the converter compared to DC converters of the same design, but at lower efficiency levels. The lower heat produced by the DC converter associated with higher efficiency can still be effectively dissipated by convection at higher temperatures, ensuring an adequate cooling effect. In non-isolated DC converters and regulators, the efficiency is a few percentage points higher due to the differences in circuit layout; here, efficiency reaches a maximum of 97%, meaning that only 3% of the power on the input side is converted to heat. Converters of this type can be rated at 7.5W in a construction size that would only allow 1W in isolated DC converters.