It is often the case, in circuits which use a transformer, that the performance of the circuit is significantly dependent on the characteristics of the transformer. This is true not only in power circuits, but in the case of RF circuits as well. For example, a multi-output flyback power supply uses a coupled inductor as the “transformer.” In this topology, the regulation, ripple, stability, and component stresses are all related to the magnitude, as well as the location of, the various leakage inductance terms, as well as, the mutual inductance of the transformer.
This is a well known and documented concern¹; however, many transformer datasheets and specifications include only a single measurement for leakage and winding inductance. This paper shows how to use the OMICRON Lab Bode 100 network analyzer to extract the transformer characteristics, including the magnitude and the location of the leakage inductance terms, the mutual inductance, and the capacitance terms.