Abstract: An electric current detector which is mountable on a circuit board on which there is mounted a fluxgate-type magnetic sensor IC chip which detects magnetic flux for electric current detection, including: a substantially ring-shaped core which forms a magnetic-path for magnetic flux induced by detection-target electric current, wherein the core includes a gap which is arranged to become substantially parallel with respect to the circuit board when mounting the aforesaid electric current detector on the circuit board and which is at a place positioned on or on the upper side of the magnetic sensor IC chip in the magnetic-path when mounting the aforesaid electric current detector on the circuit board.

Abstract: An electric current detector which is mountable on a circuit board on which there is mounted a fluxgate-type magnetic sensor IC chip which detects magnetic flux for electric current detection, including: a substantially ring-shaped core which forms a magnetic-path for magnetic flux induced by detection-target electric current, wherein the core includes a gap which is arranged to become substantially parallel with respect to the circuit board when mounting the aforesaid electric current detector on the circuit board and which is at a place positioned on or on the upper side of the magnetic sensor IC chip in the magnetic-path when mounting the aforesaid electric current detector on the circuit board.

Abstract: A flat acoustic transducer (100) includes a permanent magnet (10) and a magnetic member (20), which are arranged adjacent to each other with a predetermined interval, a flat vibrating membrane (30), provided facing the permanent magnet (10) and the magnetic member (20), and at least one coil (40), fixed to the vibrating membrane (30). In the flat acoustic transducer (100), an electrical signal is applied to the coil (40), to obtain vibration force (F) on the vibrating membrane (30) by way of a magnetic flux ? generated between a magnetic pole face (12) of the permanent magnet (10) and the magnetic member (20), a step (50) is provided between the magnetic pole face (12) and the upper face (22) of the magnetic member (20), while at least part of a winding (42) of the coil (40) at the time of no application of an electrical signal is arranged inside the step (50).

Abstract: A flat acoustic transducer (100) includes a permanent magnet (10) and a magnetic member (20), which are arranged adjacent to each other with a predetermined interval, a flat vibrating membrane (30), provided facing the permanent magnet (10) and the magnetic member (20), and at least one coil (40), fixed to the vibrating membrane (30). In the flat acoustic transducer (100), an electrical signal is applied to the coil (40), to obtain vibration force (F) on the vibrating membrane (30) by way of a magnetic flux ? generated between a magnetic pole face (12) of the permanent magnet (10) and the magnetic member (20), a step (50) is provided between the magnetic pole face (12) and the upper face (22) of the magnetic member (20), while at least part of a winding (42) of the coil (40) at the time of no application of an electrical signal is arranged inside the step (50).