摘要 |
A system for controlling the air/fuel ratio input to a small engine measures the oxygen level in the engine's exhaust and compares it with a reference level. A stepper motor controls the air/fuel ratio and it is advanced one step each time a clock pulse is produced in a direction determined by the level of exhaust oxygen. A fault detector circuit stops the engine if the sensed oxygen level is outside a preset range for more than a preset time interval.
|