Magnetic core, coil assembly and power supply circuit using the same

摘要

A magnetic core has an open magnetic path and includes a magnetic body forming the open magnetic path and having a soft magnetic property, and a permanent magnet at least at one end of the magnetic path of the magnetic body. A coil assembly includes the magnetic core having the open magnetic path. The magnetic core includes the magnetic body forming the open magnetic path and having the soft magnetic property. The coil assembly also includes the permanent magnet at least at one end of the magnetic path of the magnetic body, and at least one coil having at least one turn wound around the magnetic core. A power supply circuit includes the coil assembly. The coil assembly includes the magnetic core having the open magnetic path. The magnetic core includes the magnetic body forming the open magnetic path and having the soft magnetic property. The coil assembly further includes the permanent magnet at least at one end of the magnetic path of the magnetic body and at least one coil having at least one turn wound around the magnetic core. In the power supply circuit, a magnetic field is generated in response to an exciting current that flows through the coil of the coil assembly when an input voltage is applied, and is also applied to the magnetic body having the soft magnetic property. The magnetic field is opposite in direction to a magnetic field which is applied to the magnetic body having the soft magnetic property by the permanent magnet.