If i buy a simple pc power supply and turn it on by connecting black and green wire together (common power supplies colors for this trick) , the 5V from the red (common 5V cable) will be safe enough for my project leds servo sensors lcd etc ??? I show a lot of guides , some of them made it so easy as i described it and some other followed the hard way soldering resistors etc to their power supplies , it will work as simple as connecting black and green cable ? thanks !
It will automatically power up the arduino , so after the black-green connection is made (maybe i put a switch there) it will have load at no time.