| 摘要 |
<p>PURPOSE:To obtain the detecting device capable of detecting abnormality of a semiconductor strain gauge by adding a dummy acceleration signal to a detecting element and forcing an acceleration sensor to output an electric output signal. CONSTITUTION:An acceleration sensor 11 consists of a bridge circuit of semiconductor strain gauges and a constant current is supplied to the bridge circuit from a constant current circuit 12. The sensor 11 outputs a voltage signal whose value corresponds to the quantity of the operating acceleration and this detection signal is outputted through an amplifying circuit 13. A dummy acceleration generating circuit 14 is connected to the bridge circuit and the constant current supply from the circuit 12 is turned on and off through a switch SW to shift the balance of the bridge circuit, thereby entering a same state equivalent to the application of the acceleration. At this time, dummy acceleration appears in the detection signal of the sensor 11. Then an abnormality detecting circuit 15 monitors the detection signal from the sensor 11, whose abnormality is indicated with the signal from the sensor 11 when the dummy acceleration is applied from the the circuit 14 with the switch SW on.</p> |
