Big chokes 31 bucks

Author	Message
Warpspeed Guru Joined: 09/08/2007 Location: Australia Posts: 4406	Posted: 06:25am 06 Mar 2020       There is enough information there to reverse engineer that. Green/yellow core looks like Micrometals powdered iron mix 40. Part number T520-40D which is the largest size available. 5.2" OD, 3.08" ID, height 1.6" Published Al value 240nH for one turn.  Fifty one turns 51 x 51 x .24uH = 624uH which is pretty close to what you measured. It very likely has 50 turns. Looking at the magnetization curve, it has a very soft saturation characteristic. At 100 Orsteads about 40% of initial permeability. That works out to 40% of 624uH = 250uH at 52 amps. At 200 Orsteads about 22% of 624uH = 55uH at 104 amps. All very nice, and pretty fair value for $31 US dollars. That's about roughly $50 Aussie bux. Nice find Ben. Cheers,  Tony.