I would like to have some inductors lying around that I could use in filter/switching applications. They shouldn't have issues with being magnetized in one direction and loosing inductance because it's DC. It'll probably be 10-400kHz switching. I have looked for inductor kits, and they are either not well documented, way too expensive, or too low power. And some of them are even listed as "1/4 watt" inductors (though real power or current would make much more sense). Some of them looked almost acceptable, but they were SMD, and I really don't want to have to solder SMD.

They would need to be able to handle a few amps, or at least if put in parallel. The physical size doesn't matter, as long as it's not extremely large. So if I can only buy one or two values, what would be reasonable inductances to look for? Should I be looking for a few uH, 10s of uH, or a few mH? And what material should I look for? I do not want to have to have huge capacitors in my circuits, but I would have a lot more flexibility with the capacitance. Also, I will try and get them off amazon because you can get much better prices there, as opposed to a more reliable seller like mouser or digikey.

 

An inductor for a filter application is very different from an inductor for a switching application (I'm assuming you mean switching regulator). For a filter, you want inductors to be better than 5% tolerance. For switching applications, your main concern will be the current carrying capability. As for not wanting to use SMD, I'm afraid you might be out of luck. It's time to leave the 19th century and boldly come into the 21st century. Learn to solder SMDs - it's really not all that difficult.

 

They would need to be able to handle a few amps, or at least if put in parallel. The physical size doesn't matter, as long as it's not extremely large. So if I can only buy one or two values, what would be reasonable inductances to look for? Should I be looking for a few uH, 10s of uH, or a few mH?

Probably the most productive approach would be to look at the data sheets & app notes relating to the switching regulator chips you figure on using (for for chips that operate similarly to some circuit you're designing), and note what inductors they recommend using (usually they'll show a table of inductors & their mfgrs). That's what I did, and it worked out well.

 

An inductor for a filter application is very different from an inductor for a switching application (I'm assuming you mean switching regulator). For a filter, you want inductors to be better than 5% tolerance. For switching applications, your main concern will be the current carrying capability. As for not wanting to use SMD, I'm afraid you might be out of luck. It's time to leave the 19th century and boldly come into the 21st century. Learn to solder SMDs - it's really not all that difficult.

I may want to use some in audio filter applications, where the current capability might be a little more relevant. I know they are different, but I could probably measure the values for better precision.