Jewel piece e.g. bracelet, for e.g. social symbol, has microcontroller delivering voltage induced by magnetic field generated by key coil, to electro-magnet coil when decoded code signal relates to key code to actuate opening mechanism

摘要

The piece has a catch with a coil (1) in which an alternating voltage is induced by magnetic field generated by a coil of an electronic key in the form of a credit card. A capacitor (4) is charged by the voltage. A microcontroller (7) decodes a code signal emitted by the key and delivers the voltage via a MOS transistor (8) to an electro-magnet coil (9) when the decoded signal relates to a key code, to actuate an opening mechanism (10). The flat coil of the key generates the magnetic field only when a push button of the key is actuated.