US Patent 7518954 Motion transducer

A motion sensing transducer is disclosed that includes a case having an inner surface, a first cap that closes the case at a first end and a second cap that closes the case at a second end. The case inner surface, first cap and second cap define a space within the case. The apparatus further includes at least one inner plate member separating the space into at a first compartment and a second compartment within the case, a coil-magnet assembly that produces a signal when subjected to motion, the coil-magnet assembly disposed immediately within the case and in the first compartment, and an electronic circuit disposed within the second compartment that modifies the signal.