Which sensor converts knock vibrations into electrical signals?

Which sensor converts knock vibrations into electrical signals?

• A. Magnetic
• B. Hall-effect
• C. Optical
• D. Piezoelectric

Answer: (D)

Knock detection hinges on turning rapid engine vibrations into an electrical signal. Piezoelectric materials generate an electrical charge when they are mechanically stressed, so a piezoelectric sensor directly converts the high-frequency knock vibrations into a voltage that the engine control unit can analyze. This fast, dynamic response suits knocking events perfectly, with little lag and high sensitivity to quick pressure changes. Magnetic and Hall-effect sensors respond to magnetic fields rather than mechanical vibrations, so they aren’t appropriate for transducing engine knocks. Optical sensors detect light, not pressure waves. For these reasons, the piezoelectric option best fits the task of converting knock vibrations into an electrical signal.

Knock detection hinges on turning rapid engine vibrations into an electrical signal. Piezoelectric materials generate an electrical charge when they are mechanically stressed, so a piezoelectric sensor directly converts the high-frequency knock vibrations into a voltage that the engine control unit can analyze. This fast, dynamic response suits knocking events perfectly, with little lag and high sensitivity to quick pressure changes.

Magnetic and Hall-effect sensors respond to magnetic fields rather than mechanical vibrations, so they aren’t appropriate for transducing engine knocks. Optical sensors detect light, not pressure waves. For these reasons, the piezoelectric option best fits the task of converting knock vibrations into an electrical signal.