Contactless igniton circuit for internal combustion engines

摘要

The present invention relates to a contactless ignition circuit for internal combustion engines wherein a primary short-circuiting current flowing through the primary winding of an ignition coil is made to flow through a power transistor controlled to be conducted and interrupted by a programable unijunction transistor and a potential dividing type capacitor is connected to the anode electrode so as to operate this programable unijunction transistor when the wave height value of the primary short-circuiting current flowing through the above mentioned primary winding becomes maximum so that a spark plug connected to the secondary winding will be operated to ignite at a high sensitivity.