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I recently aquired an adjustable power supply and would like to know if its suitable for my project.

It is a 300W power supply with the following specifications:

  • Input voltage: 13V - 62V
  • Max input current: 5A
  • Output voltage: 0V - 60V
  • Max output current: 5A

Manual can be found here, specifications are on pages 4 and 5.

My project requires 19V with maximum load of 7.2A. From what I calculated, my project needs about 136W of power and that is well under the rating but at 19V the output current needed (at maximum load) is 7.2A and that is over the max output current rating.

Can the power supply give out the needed 7.2A even though it goes over the current limit but the wattage is still under the limit?

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    \$\begingroup\$ You shouldn't exceed ANY of the Maximum ratings. \$\endgroup\$ – Peter Bennett Nov 2 '16 at 22:18
  • \$\begingroup\$ How long does it need the 7.2A for? Is it an inrush current? Or long term? \$\endgroup\$ – Voltage Spike Nov 2 '16 at 22:32
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    \$\begingroup\$ The manual (and wow, it is one lousy piece of typesetting) does not say, "well, you can maybe use more than 5A if you don't exceed the power rating". It says "0~5A". They don't guarantee anything at all if you exceed 5A. Why would you for one moment imagine otherwise? \$\endgroup\$ – Tom Zych Nov 2 '16 at 22:35
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Yes you are exceeding the specifications.

7.2 is greater than 5.

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  • \$\begingroup\$ 7.2 -5 = 2.2 hmm... yes that does seem to be true \$\endgroup\$ – Makoto Nov 2 '16 at 22:45
  • \$\begingroup\$ Moreover, it's significantly greater. You might get away with 5.1A or 5.2A, those being 2% and 4% over spec respectively. 7.2A is 44% over spec. That's a good way to ruin the supply. Fuhgeddaboutit. \$\endgroup\$ – Tom Zych Nov 2 '16 at 23:05

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