PHYSICAL QUANTITY DETECTION DEVICE AND PHYSICAL QUANTITY DETECTION DEVICE CONTROL METHOD, AS WELL AS ABNORMALITY DIAGNOSIS SYSTEM AND ABNORMALITY DIAGNOSIS METHOD

An angular velocity detection apparatus 1 (i.e., physical quantity detection apparatus) includes a gyro sensor element 100 (i.e., physical quantity detection element) that allows an angular velocity detection signal that corresponds to the magnitude of an angular velocity (i.e., physical quantity) and a leakage signal of vibrations based on a drive signal (square-wave voltage signal 22) to flow through a detection electrode, a driver circuit 20 that generates the drive signal, a synchronous detection circuit 350 that performs a synchronous detection process on a detection target signal 36 that includes the angular velocity detection signal and the leakage signal based on a detection signal 34 that is synchronized with the drive signal, and a phase change circuit 352 that changes a relative timing of at least one of a rising edge and a falling edge of the detection signal 34 with respect to the detection target signal 36 based on a control signal 64 so that at least part of the leakage signal is output by the synchronous detection process.