It is used to achieve voltage regulation and conversion of power. SMPS functions in three stages—input rectifier, where AC is converted to DC; inverter phase, where again the DC is converted into inverted AC; and output rectifier stage, where the inverted AC is given to the high winding transformer.
SMPS is the board on which electronic components are assembled for the regulation of electric power. In it, input AC voltage is converted into low DC voltage. It is used in PCs so that every part of the PC gets proper power supply separately. It helps split the power to motherboard, hard disk, floppy drive, CD drive, etc. It contains several wires of multiple colour.
Each wire carries different amount of voltage value, which will pass to different hardware parts of the computer. The Table 1.3 shows the different colour cables and amount of voltage they carry.