Power supply and pickup system capable of maintaining stability of transmission efficiency despite changes in resonant frequency

A power supply device supplying power to a moving object using magnetic induction, the power supply device comprising:

• a power supply coil which is arranged to extend in a traveling direction of the moving object and through which a current flows to form a magnetic field;
• and
• a power supply core adjusting a direction of the magnetic field and having a plurality of magnetic poles extended to be parallel to the traveling direction of the moving object,
• wherein the power supply core is arranged with respect to the power supply coil so that two neighboring magnetic poles of the power supply core have different magnetic polarities and a direction of the magnetic field at the magnetic poles of the power supply core is perpendicular to the traveling direction of the moving object, and
• wherein Q-factor of the power supply device is less than 100, said Q-factor is determined by
• Qs
• =
• wLs
• Rs
• ,
• wherein said w is an angular frequency of the current, said LS is an inductance of said power supply device, and said RS is a resistance of said power supply device,
• wherein a cross section of the power supply core perpendicular to the traveling direction of the moving object has a pair of I-shapes adjoining each other and said power supply coil is arranged in parallel to the traveling direction of the moving object in the power supply core, wherein said power supply coil is disposed in each of said I-shapes.