| 摘要 |
PROBLEM TO BE SOLVED: To reduce the magnitude of self oscillation of a power supply portion with a load portion unattached, with simple circuitry. SOLUTION: A power supply portion 10 is provided with a secondary coil Nf2 for signal transmission which is not coupled with a primary coil Nm1 for power transmission, electrically or magnetically, and operates as the feedback coil of a switching element FET1. A load portion 20 is provided with a secondary coil Nm2 for power transmission, which when attached to the power supply portion 10 is opposed to the primary coil Nm1 for power transmission, and a primary coil Nf1 for signal transmission placed at a position opposite to the secondary coil Nf2 for signal transmission. When the load portion 20 is not attached to the power supply portion 10, no voltage is produced in the secondary coil Nf2 for signal transmission as a feedback coil, and switching of the switching element FET1 is performed intermittently. |
