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
Salvo wrote:
LOL, if that's your way out. I would rather man-up than weasel out.
Sal
Actually, Sal, I’d like to discuss the topic rather than devolve into personal attacks.
My point regarding generators is that they’re far from a perfect power source. You might have spikes or sags in the output, depending on how they’re loaded or how they’re designed. A generator could have a defect which causes it to lose regulation under certain conditions. Overvoltage during a power-on event could cause the filter caps in that converter to draw more current than they would at normal voltage levels. And again, if the thermistor is hot when this happens…all the worse.
Or, what happens if there is an undervoltage event during steady-state operation? The converter itself will demand a sudden increase in current.
Here’s a good link that discusses a lot of these possibilities:
http://powerelectronics.com/site-files/powerelectronics.com/files/archive/powerelectronics.com/mag/605PET20.pdf
Figure 2 is particularly revealing. Look at the voltage surge and the corresponding spike in input current following a voltage sag.
