Patent ID: 8171791

Claim:
A rotation sensor configured to be mounted on a rim of a wheel, the rotation sensor comprising: a band sized and shaped to fit around the rim of the wheel; a first element mounted on the band that generates a first time-varying electrical signal in response to a rotational movement; a second element mounted on the band that generates a second time-varying electrical signal in response to the rotational movement; a processor mounted on the band that receives the first and second time-varying electrical signals from the first and second elements respectively, and processes the first and second time-varying electrical signals to determine a rotational speed; and a rechargeable power source that receives the first and second time-varying electrical signals from the first and second elements respectively, consumes at least a portion of the first and second time-varying electrical signals to recharge the rechargeable power source, and generates a power signal, and wherein the processor is connected to the rechargeable power source to receive the power signal.