Abstract: This is a technology for non-contact power transmission to the laboratory animal biological information acquisition device 12 embedded in the multiple laboratory animals in the breeding cage 14, and provides the power reception device, which can observe the behavior of laboratory animals from outside without covering the breeding cage 14 with the power transmission side, and which can continuously supply power regardless of the direction and position of the laboratory animals. The secondary coil part 22 includes a magnetic core 31 having a circular cross-section perpendicular to the longitudinal direction, and a plurality of spiral coils 40a and 40b formed by winding a conductor so that the outer shape is substantially rectangular.

Abstract: In a power transmission system for transmitting electric power from the primary side power feeding coil to the secondary side power receiving coil without their mutual contact and using electromagnetic induction, the power coils on each of the primary and secondary sides include a pair of planar spiral coils which are shaped in the form of a figure 8 and connected differentially to power supply, and each of the spiral coils is D-shaped having a semicircular portion and a linear portion combined together, the two spiral coils having their linear portions laid one on the other to form a planar figure-8 coil. Plates of soft magnetic material 4 and 41 are disposed each on a side of the power coil on one of the primary and secondary sides which is opposite to the side that faces the power coil on the other of the primary and secondary sides.