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:
The converter is a constant power device. If input voltage goes up, converter demand for input current goes down. The feedback loop of the converter's error amp is very fast; a fraction of a 60 Hz cycle.
Looking at voltage surges as the problem is a wild goose chase.
Every converter has this part/function. There are millions of converters out there. Other converters do not have this failure mode.
Sal
Capacitors are not constant power devices, however, and a higher voltage across them will draw more initial current.
Overvoltage was mentioned as a only a possibility, so don't latch onto it. Some generators are not exactly well-regulated, especially during transient events.
My bet is on the relationship between how fast the caps are discharging and how slow the thermistor is cooling down...and probably also on the load presented when the converter turns back on. The combination of a heavy load, discharged caps, and hot thermistor upon turn-on is certainly going to be stressful.
Maybe there is a design flaw. But best to rule out other causes first, dontcha think? After all, this company probably has a lot of those converters out there, and unless they are failing by the boatload, then perhaps there is something going on with the application, or maybe some other defective components.
