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In a contactless ignition control system having a dwell time control circuit for an internal combustion engine, there is provided a speed responsive bias voltage circuit, a bias voltge switching circuit and a wave shaping circuit. The speed responsive bias voltage changes the switching level of the

In a contactless ignition control system having a dwell time control circuit for an internal combustion engine, there is provided a speed responsive bias voltage circuit, a bias voltge switching circuit and a wave shaping circuit. The speed responsive bias voltage changes the switching level of the wave shaping circuit, thereby elongating the dwell time of the current flowing through an ignition coil. In the dwell time control, when the ignition timing comes, the bias voltage switching circuit prevents application of the speed responsive bias voltage so that the ignition timing is made irrespective of the speed responsive bias voltage.

대표청구항 ▼

A contactless ignition system with a dwell control circuit for an internal combustion engine comprising: a battery; an ignition coil having a primary winding connected to said battery and a secondary winding; a power switching circuit connected in series to said primary winding, said battery supplyi

A contactless ignition system with a dwell control circuit for an internal combustion engine comprising: a battery; an ignition coil having a primary winding connected to said battery and a secondary winding; a power switching circuit connected in series to said primary winding, said battery supplying current thereto; AC generating means for producing an alternating current signal in timed relationship with the engine; bias voltage changing means connected to said AC generating means for providing a DC voltage signal responsive to the engine speed; timing control means having a switching element and connected to said AC generating means for controlling said power switching circuit by switching on and off said switching element in synchronism with the engine; and means for switching said timing control switching element to cause said power switching circuit to stop conducting at a constant threshold level of said alternating current signal, independent of said DC voltage signal, and switching said timing control switching element to cause said power switching circuit to start conducting at a threshold level of said alternating current signal related to said DC voltage signal to elongate the dwell angle of the current flowing through said primary winding, said switching means connected to said bias voltage changing means and said timing control means and selectively applying said DC voltage signal to said timing control means in response to one of the increase and decrease in said alternating current signal to alter the alternating current threshold level at which said power switching circuit turns on.