I have a switch mode power supply, outputting 48V 20A that has a pair of NTCs (inrush limiters, I suppose) that get quite hot.
I know they’re supposed to get hot, that’s how they work. But how hot is normal?
At 25% output (1A AC input), I measure 100 degrees Celsius with my FLIR. At half output (2A AC), it’s already up to 160 degrees. Does this seem about normal? How hot should I expect it to get at full load, 4 Amps? (I know I^2 * R, how much does the R go down?)
The markings on the NTC says “NTC 5D-15”
The Wiki article about NTCs has a picture of a blown NTC due to getting too hot, I hope to avoid that!