The Ultimate ATX Power Supply Mod With USB Charging Ports

Step 6 Finish It Up

Tighten down the connections, add labels, and double check the wiring. Flip the switch and if everything is done right it should come on.
Check the voltages with a volt meter and if the minimum loads have been met the voltages should be very close to what they are rated at.

If one of the lines is over loaded or shorted the power supply will shut down, pressing the reset button or turning the power off and back on will restart it.
If it overheats it should shut down if that happens turn it off and let it cool down and make sure nothing is overloaded and that the power supply has plenty of ventilation and that its not packed with dust.

Double and triple check the wiring on the USB ports before plugging in an mp3 player or camera and test it with a USB keyboard light if you can.
Make sure that the voltage going to the USB ports is between 4.75 & 5.25v

Comments

[legoman44]

I believe USB ports are limited to 500mA. Are the two USB ports current limited in any way?

[Cyberscann54]

my laptop usb allows up to a 1000mA or 1A per port It all realy has to do with the Motherboard and what the psu can handle I have seen some that can supply 2A per port with all the hubs and other stuff out there most computer companies realized the 500mA was not enough and the keep breaking and burning out

[MaXoR]

In most cases, it would be wise to use a regulating circuit that will only output 500mA. I believe in this case however, it's VERY useful the way he set it up. I know personally that when I want to charge more then two things off my USB hub.... they both charge slower! I think in this case, it's fine. Cell phones, IPOD's, Blackberries.... all charge at over 500mA current draw. If you want to know why they limit it to 500mA......... there is no reason! There are downsides however: - USB cords stop responding after 16 feet - USB hubs which split one port into 4, only gets 125mA PER PORT!!! USB is nice, wireless is better!

[rocketman221]

usb 3.0 increases power to 900mA.

[rocketman221]

The usb ports on the power supply are connected to the 5V standby line which is limited to 2 amps.