| 摘要 |
PURPOSE:To excellently relieve the load of a power source and to improve starting ability of an engine, by a method wherein a given state, such as during the starting of an engine, during reduction in the voltage of a power source, is detected to stop energization to a heater incorported in an air-fuel ratio sensor. CONSTITUTION:An analogue switch 10 stops energization to each part of a sensor control part 100 according to the operating condition of an engine, and an energization control circuit 11 controls a switch 10. The energization control circuit 11 monitors the presence of an operating signal STA of a starter switch, and the terminal voltage of a battery mounted on a car, the output voltage of a power source part to open the analogue switch 10 during operation of a starter and decrease in a given voltage to stop energization to a heater 5 and a sensor part 4. This prevents reduction in the voltage of a power source through shut off of a load such as the heater 5 when a large amount of a current is needed during the starting of an engine, and permits improvement of starting ability of an engine. |
