About Power Cables in PC

I hope, you can recognize the power connectors discussed in our previous blog. In all new systems(Pentium-IV, AMD), on the mother board you can find two power supplies given by two power connectors(One is 20/24pin Rectangular connector and the other is 4 pin sq. connector).

While observing power supply in your PC, most of the people wonder and confused about them. Because they are many in number. It may raise one question in mind, why SMPS provides all those power connectors from inside the SMPS and why don't they split the supply externally with adoptors. Right? Because:

Wires and connectors are not perfect conductors. They have resistance. When current passes through them they suffer a voltage drop and lose that energy as heat. As long as you don't overload them the voltage drop and extra heat don't matter. But the losses get worse as the current rises. That's why you see some power cables with more that one wire for the same voltage. Having multiple wires reduces the losses. If you seriously overload a line, the wire can get fairly warm. The resistance of connectors tends to increase as they are plugged and unplugged so after enough uses they can overheat and even melt when passing a large current. So a lot of changes in connectors over time has to do with adding more wires and connectors to make sure that none of these problems occur.

Interested persons can go and view all the form factors about power supplies at: http://www.formfactors.org/ and it will give you sufficient information regarding this.

This is original PC-AT.
Power supply connectors in two-pair

Note: Observe that both black colored cables are in middle

12V 4 Pin Connector for Mother Board

20Pin ATX Power Cable & Connector for Motherboard

4 Pin Peripheral Connector (Here connected to Hard Disk)

Note: These are same for CD-ROM/DVD Drives and SATA Hard Disk but with adoptor cable specially designed for SATA Devices.

4 Pin Floppy Drive Power Cable

SATA Power Cable connected to SATA-Hard Disk

SATA - Power Cable Adoptor

And there are vaious other Power Cable Adoptors to extend/convert to various uses. Let us look into them once.

This 20 pin to 24 pin Adapter Cable converts your ATX 1.3 12V power supply (ATX 2.0 12V compatible) power supply to work with ATX 2.0 motherboards. ATX 2.0 motherboards come with 24 pin power supply connectors instead of 20 pin connectors. If your power supply only has 20 pins in its motherboard connector, it may still be 2.0 compatible. If it is, it can be used with a newer 2.0 motherboard with this connector.

Have you got a brand new power supply with a 24-pin ATX connector, but your motherboard uses a 20-pin connector? This adapter cable turns your high-end power supply’s 24-pin male ATX connector into the 20-pin male ATX connector needed by most motherboards.

The PP01 kit is a two cable package that will help extend any ATX power supply’s ATX and +12V power connectors. These are useful for system with large case or motherboards with difficult to reach plugs. Included 24pin to 20+4pin cable can also act as an adapter for 24pin power supply connecting to a 20pin motherboard.

Mini Adoptor for Floppy Drive