Murata Shock Sensor used in Omron Pedometer
Omron Healthcare employs a Murata shock sensor technology in its Walking Style HJ203 pedometer. The acceleration sensor operates on the principle of piezoelectric ceramic technology. Piezoelectric ceramic is charged with electricity when subjected to stress. The sensor has a piezoelectric beam on the inside. As this beam is accelerated by the impact generated when the user of the pedometer walks, stress is applied to the beam to generate electric charges in proportion to the stress. Using an electronic circuit , the electric charges generated are transformed into voltage, amplified, and converted into digital signals, which permits a CPU and other electronics to determine the magnitude of the acceleration. In addition to pedometers, shock sensor technology is used for detection of impact acting on hard disk drives.
Murata shock sensor used in a pedometer
Principle of shock sensor operation