Abstract: In a vibration sensing device for sensing a knocking vibration of an engine, a piezoelectric element is connected to an output terminal through a resilient conductive member. The resilient conductive member has a fixed base part, a sliding part at a position opposite to the fixed base part, and an intermediate V-shaped part resiliently contacting the piezoelectric element. When the sliding part moves slidingly in response to vibration of the piezoelectric element, the sliding friction force which exerts on the sliding part increases the spring constant of the resilient conductive member to be larger than the stationary spring constant of the same by hysteresis characteristics, thereby reducing damage to the piezoelectric element and enhancing reliability of the electric connection.

Abstract: A rotary position detector comprises an integrally molded rotor made of a synthetic resin to which a contact is fixed, a housing and a cover member on which a resistance circuit surface is formed. A contact surface and the resistance circuit surface to which the contact is attached has a cylindrical recess disposed on the same axis center as the shaft or a protrusion engaging in the recess. Alternatively, the resistance circuit surface may be provided on the rotor and the contact is provided on the cover member. A terminal contact which integrates an external contact terminal and a contact may be employed.