Spool assembly for receiving light string

A spool assembly for receiving a light string, comprising:

• a winding device, including:
• a winding portion, including a first end and a second end, and arranged along a longitudinal direction;
• a first flange, extending outwardly from the first end and perpendicular to the longitudinal direction, wherein the first flange defines at least one first latching hole;
• and
• a second flange, extending outward from the second end and perpendicular to the longitudinal direction, wherein the second flange defines at least one second latching hole;
• and
• a power transformer, including a power conversion circuit and a housing;
• wherein the power conversion circuit is arranged in the housing, and the power conversion circuit is configured to convert external power into driving power;
• wherein the housing further includes at least one protruding portion protruding from the housing and configured to be engaged into one of the at least one first latching hole and the at least one second latching hole.