Operating Temp Range

[ptonsparky]

I am looking at various power supplies and see difference in the temp operation range. The upper range is well within my temp extreme but what happens to these at the lower temp limits? (12vdc @ 50w)

 

[gar]

120105-1920 EST

I would not work toward the upper temperature rating. A higher temperature means a higher component failure rate.

At the low temperature end the likely failure is function rather than component.

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[ptonsparky]

Upper end is well beyond what I would expect.

Low end is about 14 F.

Function failure meaning the ability to maintain a steady voltage at load??

 

[gar]

120105-2006 EST

Transistor gains drop off at low temperatures. So this is the primary cause of low temperature operating problems.

Out of the hat I pulled up a datasheet for for a 7805 (5V 1A) regulator. For the non-military version they are showing -25 C. See http://www.fairchildsemi.com/ds/LM/LM7805.pdf .

More off the hat stuff. http://us.tdk-lambda.com/lp/ftp/Specs/ls.pdf If you really need 5 A, then I would choose a 10 A supply. This Lambda series appears to be rated for operation to -25 C.

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[ptonsparky]

Thank you.