I know what you mean about trying to use and test unknown/unspec'd power inductors. I was planning to build a special fixture with a MOSFET-based variable current source to look at saturation while measuring with the HP4276A. I can send some info on the project, but don't have a finished design yet - just a partial prototype. There is an HP/Yokogawa fixture for this - I can't remember the model number off-hand - but it is quite complicated, and way more than I would want to acquire or duplicate.
--- In TekScopes@..., PA4TIM wrote:
> Hi Ed,
> Thanks for the info. I have build several simple smps's (buck and boost
> converters) but the problem most times is the inductor. I can measure
> inductance, Q, R+jx, selfresonance you name it. But the problem is I
> have a box full of unknown inductors and some work and others do not
> because they saturate. And that is what I want to measure.
> I made a small saturation tester for it but then I thought it would be
> nice to have the current on the Y axis and Volt on the X axis but while
> designing that I read about the curvetracer discussion and had an Eureka
> moment. That must be able to do that too I think. I normaly just try it
> instead of asking but I do not know if the measure-circuit of my tracer
> likes inductive loads. And I'm very carefull with my nice Tek.