Patent ID: 8704625

Claim:
An energy autonomous radio transmitting device, comprising: a radio transmitter; an electromagnetic energy transducer further comprising: two magnetic elements including a permanent magnetic element and a soft-magnetic element; and an electrical coil, wherein said permanent magnetic element and said soft-magnetic element are arranged to form a magnetic circuit, and one of the two magnetic elements is movable in relation to the other of the two magnetic elements through a range of motion limited by first and second stop points, wherein said electrical coil surrounds a part of said soft magnetic element, wherein the movable magnetic element is configured to be moved into a second position by applying an external mechanical force, and wherein at the first position the magnetic flux within the soft magnetic element is different than the flux at the second position; and a storage element electrically coupled to the electromagnetic energy transducer and the radio transmitter, the storage element configured to receive and temporarily store electrical energy generated by the electromagnetic energy transducer to power the radio transmitter, wherein the device is further configured to detect a polarity of a voltage generated by the electromagnetic energy transducer and transmit an indication of the polarity with the radio transmitter.