24V 300mA to ~12V 600mA is it possible?

[koziskey]

I am helping my sister with school project. I need a power supply for led strip ~5W needed. I also have 24v power supply laying around. Is there a way to use it?

[Zero999]

The short answer is no. You can't convert 24V at 300mA to 12V at 600mA because there will always be some power loss.

Fortunately you're talking about 7.2W, which is more than enough to power a 5W LED strip from.

You could use a DC-DC converter but it's probably cheaper to just buy the correct voltage power supply.

[macboy]

Look for a "LM2596 buck" power supply on ebay or alibaba or wherever you prefer. These are small down-converting DC-DC power supplies that can do what you need. You should be able to get a module for $1 shipped. No joke. The only issue is the wait time for shipping from China/etc.

[Rick Law]

To get 12V 600mA from 24V300mA, you need exactly 100% efficiency.

It doesn't matter what buck converter you use, 100% efficiency is simply not possible.  One can always try to break the annoying Laws of Thermodynamics, but one would most likely fail.

If you do a good job, 12V 540mA (90%) is feasible.  More likely, you will be at 80-85% range done well, and much lower if not done well.

You have to pay the piper, in this case, the piper is Entropy.