I can't understand why I have such a big problem with grasping this but I have found that using a USB-device in place of a real scope makes things weird but I guess you get used to it(though that might not be a good idea
)
My Analog Discovery(AnD) has better specs than my only scope so I'll go with that until I can afford a good scope.
Did anything get hot?
Oh yeah, the heat-sink for the FET was not to be touched, I could feel the heat in my face sitting at the desk.
Here a few details anyway, in the schematic I left out 4 2200µF caps right after the power supply.
Here the leads to the AnD is removed so every component is visible.
In the pictures of waveforms so far the same inductor as in the picture above was used, I know full well what that is:
https://katalog.we-online.de/pbs/datasheet/74435586800.pdf
Inductance = 68µH
Rated current = 7.5A
Saturation current 9.5A
DC resistance = 27.3mΩ
SRF = 5MHz
But I have used two other cores wound my self and they give the same sort of waveforms. Its the two most upper in the picture below.
All unknowns.
They have all been re-wind except for the CM-choke at the left side, although its only the two coils that is highest up in the picture that is of most immediate interest.
All I am really trying to do is find a setup with which I can hook up a coil and in a couple of minute's know that I can put this and that much current through this before the inductance falls off, if a coil is used in a buck converter which input is 30Vdc. Does that coil have a 30V DC bias?
Or is a DC bias some constant level when talking about coils and its core?
I am about to test the B/H circuit I have made again to see what that gives.
When fiddling with the setup that produced the waveforms show so far I have tried the hole range of duty cycle, frequency and amplitude of gate voltage. The coils I am about to use will be used in a buck converter and I hope not to go above 200kHz for the switching frequency.
By the way, I really like the power supply used here. Its a XBOX supply that I have opened and highjacked the "Power good" signal with a flip-switch and mounted connectors to get access to its 5V 1A and 12 16,5A. See attached pictures.