Converter testing to quantify power loss
Efficiency is a key parameter when characterizing power supplies, including those that only operate at low power (<100 W). Power efficiency testing quantifies power conversion loss, so it relies on the precise measurement of both input and output power.
In final validation and compliance testing, a dedicated power analyzer - such as the LMG600 Series - is commonly employed. This instrument provides highly accurate measurements of input power.
However, power efficiency testing is not limited to the final testing stages. It is also important for the design phase, since nearly every component within the power supply circuit influences efficiency. Rapid feedback during development allows engineers to iteratively optimize the design.
This is where the oscilloscope plays a key role. As the primary diagnostic tool in circuit development, it enables designers to measure both input and output voltages and currents, from which power—and thus efficiency—can be calculated. Although the oscilloscope generally offers lower absolute accuracy than the power analyzer, it provides significantly higher bandwidth and faster sampling, along with advanced triggering capabilities. This allows engineers to observe dynamic effects and transient behavior that may impact efficiency but are not easily captured with a power analyzer.
