On 23 sty 2012, at 19:46, John Rehwinkel wrote: >> A 0R025 RSENSE resistor means that we're ramping the current up to 4A before >> releasing the energy stored in the inductor. 4A is a lot of current. The >> magnetic field produced by the inductor is so strong that it affects >> everything around it, even very carefully routed traces > >> I did some experimenting and: >> >> -- moving the inductor away is a solution, but it needs to be *far* away, >> 8cm or so, >> >> -- shielding the inductor, while improving the situation, increases the >> current consumption 2x, produces audible noise and heats up the shield >> considerably, so it is not a solution. >> >> All in all, I don't think a circuit with an RSENSE of 0R025 is feasible, at >> least not with a 5cm x 5cm board. I'll be going back to 0R050 and 0R100 and >> smaller inductors. > > Have you tried a toroidal inductor? They're better behaved in this respect, > even though they're physically large, especially for the high current one > you'd need.
Hmm, I haven't considered that. They might indeed behave better. The inductor I use is from a Polish manufacturer: http://www.feryster.pl/polski/dsz14x15v.php (except I used a 5A version). But overall I think I'll try the smaller RSENSE values first, they should be enough to provide the output currents I need. --J. -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/neonixie-l?hl=en-GB.
