If the connector on the left represents the output of a generic power supply then I still don't see how you would connect this on the laptop side.
EDIT: On further thought I think that connector must be intended to represent the laptop input and Vcc is the output of a generic power supply (with sufficient voltage and current capacity). It was not clear to me because my Dell laptop doesn't appear to have a 3-pin power connector so maybe this only applies to certain models.
EDIT: On further thought I think that connector must be intended to represent the laptop input and Vcc is the output of a generic power supply (with sufficient voltage and current capacity). It was not clear to me because my Dell laptop doesn't appear to have a 3-pin power connector so maybe this only applies to certain models.