I am using a 12V (1A) SMPS power supply to power up a device that draws about 70mA when idle and up to 200mA when active (every 3 seconds).

The power supply is getting pretty hot (about 70°C) after 1 hour of operation. I own several of these power supplies and all if them seem to have the same issue. How can this be avoided? Is 70°C a safe temperature for the operation of the components on the power supply like the transformer, etc.?

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    \$\begingroup\$ As per the specs you have mentioned, the current you are drawing is far below the maximum range...so that is surely not the heating issue. And 70C is not a safe temperature for power supply to operate. So something is abnormal here. Can you please provide more details about the load you are powering using this supply. \$\endgroup\$
    – Mayank
    Commented Jul 7, 2017 at 13:17
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    \$\begingroup\$ A link to the full specs of your power supply would help to evaluate your situation. \$\endgroup\$
    – Glenn W9IQ
    Commented Jul 7, 2017 at 13:26
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    \$\begingroup\$ See my answer to your earlier question: electronics.stackexchange.com/questions/314950/… - in short reduce output current (if that is the cause of overheat) by using a buck regulator. \$\endgroup\$
    – Andy aka
    Commented Jul 7, 2017 at 13:31

1 Answer 1


Blow air thru the supply. Or mount it UP, an inch or two off the table, for some natural convection.


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