kinarfi
Well-Known Member
Yes, I've read that, then I went and weighed my inductors,, most of which came out of power supply units for servers that were being replaced where my son works, seem they were of the HP variety.I hope you have seen this application note by Jim Williams: https://www.electro-tech-online.com/custompdfs/2012/02/an35f.pdf
He gives a lengthy and practical discussion of inductor selection. While he doesn't discuss Q specifically, he states emphatically the need for good inductors. Based on that need, he decided not to try to make the inductors in house and to use only inductors from outside vendors that are designed for switching regulators. He gives some recommended sources. I have used CoilCraft.
While it might be fun to experiment with making an inductor, for your power supply, I would suggest following William's advice.
John
I was lucky enough to have been invited to his seminars in Salt Lake City, Utah, very informative and interesting, I think he said he's the one who wrote Spice, which I use extensively. The seminar was sponsored by Nu Horizons Electronics and Würth Elektronik who sampled me some of their inductors mentioned earlier.
My latest diversion has been to modify what's working to a SEPIC design, (It worked, but then I had to go watch the game ), using a toroid inductor with 4 separate winding, they were paralleled via their connection to their circuit board. Looks like about 4 to 6 turns of #16 awg wire for each winding and about 9 uh per winding, (from memory). I series two of the windings for each part of the SEPIC transformer (~20uh) for a 1 to 1 ratio, My next diversion will be to make it a 1 to 3 ratio, up the frequency of the circuit by changing the capacitor. The FET I'm using is an IRF2805 which is rated at 75 volts, but if I were to use a lower rated FET with a lower Rdon and protect it with a series high voltage switching diode, would I lose the benefit of the lower Rdon due to the voltage drop of the diode. My high voltage FETS have an Rdon close to a 1/2 ohm and the low voltage FETs have an Rdon of less the 10 milliohms or would it even work, I'll find out.
Kinarfi