Guru
Joined: 09/08/2007
Location: AustraliaPosts: 4406
| Posted: 03:15pm 07 Mar 2017 |
Yes its all interesting stuff.
This magic inductor needs to be ferrite. Toroids or EE cores being ideal. That will give high initial permiability, but it will also saturate very quickly which is good.
Powdered iron cores are less than ideal because they are much more difficult to saturate than ferrite. In other words the inductance does not go away quite as well during high power operation.
I am becoming increasingly suspicious about some of the parts that originate from China, and particularly with power mosfets and magnetic cores. Powdered iron is dirt cheap, but ferrite is much more expensive to produce.
Ah so, lovely Chinese ferrite toriod, very nice, very cheap, you buy many yes ?
Maybe just one to try first haha.
As to why these small inductors can sometimes do really strange things to the output waveform, I have absolutely no idea.
Cheers, Tony.