20851
General Mach Discussion / Re: Where do I get my 5 volts from?
« on: December 19, 2008, 03:18:24 AM »
I use external power as I just dont trust USB power for anything Had many an external HDD work fine on one computer and then the next doesnt have enough guts in the USB to power it.
Computer power supplys produce all of the voltages internally, well that is if we are talking desktop PCs and not Laptops. On the desktop PSU the molex connectors that go to devices such as PATA HDD and CDROMs etc have both 5V and 12v, 5v is the red wire and 12v the yellow and Black is 0v. You can also get 7V there if you wish to power a fan that is too noisy on 12V but too slow on 5v, just use the 12V and 5v lines rather than one of them and the 0v The ATX connector also has 3.3v and usually -12v and all voltages from the PSU are regulated and usually fairly good regulation at that even on the cheapos (should be music to your ear ) You also have a 5V standby voltage on the ATX connector that is present even when the mobo itself is powered down, all the rest of the voltages just come on when the power good signal from the mobo is present.
Hood
Computer power supplys produce all of the voltages internally, well that is if we are talking desktop PCs and not Laptops. On the desktop PSU the molex connectors that go to devices such as PATA HDD and CDROMs etc have both 5V and 12v, 5v is the red wire and 12v the yellow and Black is 0v. You can also get 7V there if you wish to power a fan that is too noisy on 12V but too slow on 5v, just use the 12V and 5v lines rather than one of them and the 0v The ATX connector also has 3.3v and usually -12v and all voltages from the PSU are regulated and usually fairly good regulation at that even on the cheapos (should be music to your ear ) You also have a 5V standby voltage on the ATX connector that is present even when the mobo itself is powered down, all the rest of the voltages just come on when the power good signal from the mobo is present.
Hood