eldercosta

's profile
image

Biography has not been added


eldercosta

's contributions
  • 10.05.2017
  • Designing second stage output filters for switching power supplies
  • Great article, perfect timing for me, thank you very much. A few notes besides the missing figure: 1- Step 2 of technique 1, inductor selection, values are in uF; 2- “Larger inductors have larger SRFs”, isn’t it the other way round? 3- Equation numbering: (10/11) after (16), should be (17/18) 4- Step 5 of technique 2 refer to equation 17, it should be 18. I assume RFILT is RD.
  • 08.14.2017
  • The weed-eater circuit
  • I would possibly fail your test. I would answer 7.8V in about three seconds. :)
  • 04.07.2017
  • Android woes give iOS the upper hand
  • Brian, I have a Samsung S4 Mini GT-I9192 (old I know but it still works great for me - I think you share my opinion on this :) ). Sometimes when I connected it to USB or charger it started to burn, to the point the current supplied by the USB port was not enough to charge it. And it got too hot even after disconnecting. It was not unresponsive though and a reboot solved the problem. It did not happen every time I connected the charger. Firmware update did not fix it. I believe the firware enters a busy loop inside the idle task instead of being suspended, taking CPU usage to always 100%. The "fix" was accidental: I installed the 360 antivirus. It has power management functions. I do not like software with functions unrelated to its main purpose but, in this case, it turned out to be good: the phone did not show that extreme misbehavior ever since, though I still notice an abnormal charge pattern (twice as fast as the usual) sometimes. Also I noticed recently that when I connect the charger it resumes the normal power consumption pattern after disconnection. I still reboot the phone from time to tome to restore the normal pattern when I do not have a charger at hand. So it is not a fix, it is a workaround but the improvement is still worth it (from about two hours to full depletion to about two days). So my suggestion is you try this specific antivirus to check if things change.