PLC power supply generates the required dc voltage levels for operation of the internal circuit of PLC. It is a switched mode power supply which accepts wide range of AC/ DC input voltages. Parts of PLC Power supply are:
1) Line conditioner: Line conditioner unit filters the input AC voltage and removes any glitches,noise, EMI
2) Converter: Converter unit converts AC into DC This is basically a switched mode power supply.
3) Regulator: Regulator unit generates the required voltage levels for the PLC internal circuit Battery Backup: for reliable operation of PLC, there is a battery backup. In the event of power failure from AC input, Battery backup becomes active and prevents accidental shut down of PLC