Converter In-Rush Thermistors etc, UPDATE -4
UPDATE on 17 Nov, Update 2 on 22 Nov, Update 3 on 16 Jan 14, Update 4 on 19 Oct 14. --------------- In a recent thread there was mention of how you can wreck your gizmo (in my case a converter) ...
Forum Discussion
ken white wrote:
Unless the 2 Ohm Thermistor can handle 2.5 times more energy than the 5 Ohm Thermistor, it will have less excess energy capacity given the same set of conditions...
It will also allow over twice the surge current to flow, which is what it should be limiting...
And it will have 6.25 times the power being dissipated for the 2.5X increase in current flow. These numbers aren't exact. The faster current flow charges the caps faster, and reduces the current flow sooner. Still, the thermistor is failing due to heating, and that heating is a result of inrush current flow and is proportional to that current squared. Reducing current flow and spreading it out over time are both effective means of reducing the heating that is blowing up the thermistor. Increasing R does both.
