sonnyyu:
I built a 5V 6A power supply (30W max) for a LED sign
The typical LED is drived by constant current power supply, but you try do constant voltage one. Could you show us detail of your LED sign?
Sure. I forgot to mention 6A max, the power supply design does UP to 6A (chip is capable of 8A), sorry for not making this clear earlier. In testing with one module and a mockup board, I was seeing no more than 0.5A max for one board, I just want to build in some room in case more LEDs are lit at once, or the brightness is turned up. The LED boards are 5V, 1.37A max, average ~0.3-0.5A requirements / board.
(and thanks for the replies)
I'm using 4 of these: http://www.sureelectronics.net/goods.php?id=1095
The datasheet states a max load of 1.37A with all LEDS on and 100% pwm. While I am not intending to run at 100% brightnesss, or with every LED on at the same time, 4x 1.37 = 5.48. Add an additional 200-300mA (generous) for the controlller + bluetooth module, and I figure at least 6A is enough (although the PS I'm using is capable of 8A. The power source I am using is capable of 15A @ 12V.
My project is being posted to a github page, so far only a few datasheets/BOMS are posted, however I have posted my Power Supply, as I've tested it to deliver 5V so far, but have not tested the current capabilities yet. If you are interested, please see: GitHub - evanrich/92x16LED-Display: Custom made scrolling LED sign 92 dots wide by 16 tall.
The power supply centers around a TI LMZ12008 Simple Switcher power module (LMZ12008 data sheet, product information and support | TI.com) This is the first power supply I've designed, so it may not be perfect, but I'd like to see if it can at least deliver the 6A @ 5V that I need.
Thanks again!