Patent ID: 9022010
Filing Date: 2015-05-05
Classification: F02P,H01T

Abstract:
1. An ignition system, comprising: a spark coil which is provided with a primary coil and a secondary coil electro-magnetically connected to the primary coil, and a spark plug having a center electrode and a ground electrode, the spark plug causing discharge sparks in between the electrodes by applying a high voltage across the electrodes on the basis of an electro-magnetic energy stored in the spark coil; wherein one of two ends of the secondary coil is connected to a member which is at a standard electrical potential via a low-voltage side path, and another end is connected to the center electrode via a connecting path; a constant-voltage path is connected with the connecting path, wherein one of ends of the constant-voltage path is grounded or connected to the side of the secondary coil of the low-voltage side path; a constant-voltage element is disposed within the constant-voltage path, wherein when electricity is supplied to the primary coil, the constant-voltage element allows current to pass through the constant-voltage path only in a specified direction that renders polarity of an inductive voltage generated in the secondary coil to turn from negative to positive, and when electricity to the primary coil is cut off and then a voltage across the terminals of the constant-voltage element becomes the specified voltage or more, the constant-voltage element allows current to pass through the constant-voltage path only in a direction opposite to the specified direction and decreases voltage equivalent to the specified voltage; and the ignition system further includes a restricting element for restricting the current that passes through the constant-voltage path in the specified direction when electricity is supplied to the primary coil.