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Does anyone have suggestions for the 5v power supply for the 8x8x8 LED cube by Chr? Answered

The step about the 5v psu for the LED cube is confusing, at least to me. Here is the page about https://www.instructables.com/id/Led-Cube-8x8x8/step33/Build-the-controller-Power-terminal-and-filtering/ . At first I was going to use the lm7805 but then it said that they took it out. All the pictures show the original design and I don't understand how they replaced it. Someone in the comments talked about using the lm2575 but I am confused.




Best Answer 5 years ago

You could use an actual 5v wall wart, or something.

If I used a 5v one, would I need something to replace the lm7805? What should the mA rating be?

They make dozens of styles, with a variety of current ratings that will suit your needs. Try Amazon or something. Make sure you get one with a higher current rating than what your project requires, or else... you know.

Could I use a 9v battery with the 7805 and put the black/red battery wires in the terminal connector?

You'd be dropping four volts across the regulator. That's a lot of power to be converted to heat. Try using four AA batteries. That's six volts, so you'll only be dropping one. Plus four AA's will provide power for longer than a nine-volt battery.

The Instructable was tl;dr, but I got the gist of it. The 7805 outputs five volts. If you put five volts in, you really don't even need it. If you use a five volt wall wart, use a multimeter to make sure it is actually putting out five volts. They are generally unregulated, and some will go as high as six or seven volts. If they do, use a 7805 to make sure it stays at five volts. Other than that, the rest should be the same. Post pics of your cube when you finish.

I think I'll get the lm7805 just in case. It will be a while before I finish it because most of the parts I ordered on eBay come in on the east coast but I will get it done eventually. :)

Most wall supplies are unregulated. Definitely have a 7805 in there to keep it where it should be. Don't forget a sink!

If you put your mouse on the image notes (just over the smaller of the 2 overlapping notes on image one), it says "This was removed later because it couldn't deliver the needed amps"

In the write-up for this step, the author wrote,"The LM7805 was later removed, and a wire was soldered between the input and output pins. Instead we used an external 5V power source, as covered in a previous step."

Does that answer your question? (Its probably a good idea to thoroughly read the full Instructable before attempting it).

I read that part but I don't know what it means by 'a wire was soldered between the input and output pins'. I guess I don't know what that should look like.