| 摘要 |
PURPOSE:To permit ignition timing to be advanced only in the range where air- fuel ratio is lean in a carburetor type engine by electrically detecting the displacement of the piston of a variable venturi type carburetor and elctronically controlling the ignition timing according to the variation of the piston. CONSTITUTION:When an intake negative pressure is introduced into a negative pressure chamber (e) by a variable venturi type carburetor, a diaphragm 7 is operated according to the pressure difference between the negative pressure chamber (e) and a pressure switch chamber (f), and contacts 17 and 18 are allowed to contact, and a pressure switch 6 is turned ON. Then, a transistor 34 for air-fuel ratio correction advance is put into electric conduction in an electronic ignition-timing control circuit 8, and the electric-discharge speed of a condenser 30 is increased and the ignition timing is advanced. Therefore, the ignition timing only in the range where the air-fuel ratio is lean can be advanced. |
