Draw the block diagram for PLC power supply and explain the function of each block.
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