Switchable low threshold current power supply

A device connectable to an electric power line conductor comprising:

• an electrically conductive insulated first winding of wire wound into at least two turns having a first end and a second end, wherein the first end is configured to be attached to a first power line conductor;
• an electrically conductive insulated second winding of wire wound into at least one turn having a first end connected to the second end of the first winding of wire and a second end configured to be attached to a second power line conductor;
• and
• a switchable connecting device configured to move between a first position connecting the first power line conductor in series with the second power line conductor, a second position with the first winding of wire in series with the first power line conductor and the second power line conductor, and a third position with the first power line conductor, the first winding of wire, and the second winding of wire connected in series with the second power line conductor, wherein the switchable connecting device includes a manual tap selector switch and a by-pass switch that are mechanically connected by a common shaft to move together when moving between the first position, the second position, and the third position.