Testing pulse transformer with an oscilloscope

Pulse transformers are little different from regular AC transformers. In AC transformers magnetic flux alternates between negative and positive values in core while in pulse transformers magnetic flux is unipolar. Pulse transformers are used in TV, computer power supplies. If you need to test pulse transformer it may be almost impossible to do this with ohmmeter even digital one because windings of impulse transformer have very low active resistance except high voltage ones. One way to test is to measure inductance of windings and compare them to values in specifications, but not everyone has ability to measure inductance and not always you have transformed specifications near by. So there is another way to test pulse transformers which may be acceptable to almost everyone radio-hobbyist. By using low frequency generator which works at resonance frequency of contour which consists of external capacitor and pulse transformer winding.  

Continue reading