| 摘要 |
<p>PURPOSE:To prevent using up of a battery due to power consumption of a gas sensor, by providing a ripple detecting circuit to detect ripple voltage overlapped on an electric power source at rotation of an engine on a sensor part, and supplying current to the gas sensor by the output. CONSTITUTION:While an engine is on between B, G terminals of a battery 6, a ripple is generated corresponding to the rotating speed of a generator interlocked with the engine, and when the engine is off, voltage of the battery 6 without ripple is generated. The ripple is detected with a ripple detecting circuit 8, the output is input to a first control circuit 2, the circuit 2 supplies current to a gas sensor 1 during input the on-signal of the engine, the output is taken in to perform a computing process, and infrared rays are transmitted from a transmitting circuit 5 at prescribed intervals. When the circuit 8 outputs a signal indicating an engine stop, the transmission of the infrared ray signal is stopped after a prescribed time, and the current supply to the sensor 1 is stopped to reduce a current consumption.</p> |
