Power module

A power module comprising:

• at least one power source, each power source comprising an end defining a socket;
• at least one external power line, each external power line comprising a plug, the plug being inserted into the socket;
• at least one fixing piece fixed at the end of the power source;
• and
• at least one clamping piece, each clamping piece comprising:
• a base mounted on a corresponding one of the at least one fixing piece;
• two parallel fixing portions extending from the base, wherein a slot is defined between the two parallel fixing portions, one of the fixing portions comprises a hook extending in the slot;
• and
• a clamping band comprising a fixed end fixed on the base and a slide end;
• wherein the slide end comprises a number of spaced fixing teeth, a fixing groove is defined between each two of the fixing teeth, the clamping band winds around a corresponding one of the at least one external power line, the slide end is inserted into the slot, the hook is engaged with one fixing groove to lock the slide end in the slot, and the clamping band and the base cooperatively hold the corresponding external power line.