Power supply and power control circuit diagrams / circuit Power supply and power control circuit diagrams / circuit schematics. Note that all these links are external and we cannot provide support on the circuits or offer any guarantees to their accuracy. Some circuits would be illegal to operate in most countries and others are dangerous to construct and should not be attempted by the inexperienced. ATX Power Supply Pinout and Connectors COMPUTER POWER SUPPLY: PINOUT, CABLES, CONNECTORS. Standard ATX power supplies typically have the main power connector P1, additional 12V connectors, as well as peripheral, floppy drive, serial ATA, and PCI Express® receptacles, which we will describe below. For the operation basics of SMPS PSU see our power supply tutorial.