I asked more or less this exact question a few weeks ago. Buy a multi volt adapter. Cut a section in the wire, you don't have to snip of the end, strip the plastic off so you have 2 wires, one will be black one will be black with white stripes. Get the fan, strip the red and black wire. Then wrap the red wire around the white stripe black adpater wire. And wrap the black fan wire around the black adpater wire. Insulate with tape. You can have a whole series of fans on one adapter. Good luck.