| 摘要 |
PURPOSE:To prevent worsening of blow-up of an engine due to retard, by comprising a retard amount setting circuit, which changes a retard amount depending upon a negative pressure in a suction pipe and the number of evolutions of an engine, and an output circuit which provides the output of a controlled ignition timing. CONSTITUTION:A signal responsing to a negative pressure in a suction pipe inputted from a boost sensor is sent to a converter 5 and a differential amplifier 6, and the converter 5 compares the signal with a reference voltage signal. When the boost is decreased to lower than a given value, a signal is inputted to a different single stable multivibrator 7, and a signal, by means of which a time to be retarded is set, is sent from the vibrator to an output circuit 2. An output signal from a rotary sensor 3 is sent to the differential amplifiers 6 and 8 to input it to the time constant setting part of a vibrator 4. The vibrator 4 outputs a retard signal, having an increased time constant as the output of the rotary sensor 3 is increased, and a decreased time constant as a value from the boost sensor is increased to feed the signal to the output circuit 2, and this enables prevention of worsening of blow-up due to retard. |
