PURPOSE: To realize a low cost self-diagnostic function which can be driven with a normal power supply for IC by providing a driving power supply for feeding current to a first conductor path formed on an overlapped part and a second conductor path opposing thereto.
CONSTITUTION: In case of normal detection of acceleration a beam 2 flexes upon application of acceleration to displace the overlapped part 3 upward or downward with the beam 2 as a fulcrum. Consequently, stress is generated in the beam 2 and the resistance of a piezoelectric resistor 10 varies. The acceleration is detected based on the variation of resistance. In case of self-diagnosis, a driving power supply feeds driving current to first and second conductor paths 11, 12 and the current flowing through the conductor path 12 induces a magnetic field H in the vicinity of the conductor path 11 which is thereby subjected to Lorentz force. When the opposite currents flow in same direction, attraction takes place otherwise repellency takes place. Consequently, the overlapped part 3 is displaced and since the application of acceleration can be simulated, self-diagnosis is realized.
UCHIKOSHI SUSUMU
KIYOTA SHIGEYUKI
MURO HIDEO
