Abstract: This invention provides a speed sensitive device for controlling the speed of an engine. A tachometric generator is provided which supplies a voltage or a function of the engine speed, and this is compared with a reference voltage which is a fraction of the voltage of the battery.In a first stage of the comparison the voltage supplied by the tachometric generator is compared with a reference voltage fixed by a dividing bridge, which determines a comparison threshold so that, when the voltage supplied by the tachometric generator exceeds this threshold, the first stage triggers a second stage of comparison, similar to the first, which compares the voltage from the first stage with another reference voltage fixed by a second dividing bridge, this second triggering causing actuation of a switching component to modify the ignition of the engine.

Abstract: An ignition device for an internal combustion engine of the kind having an ignition coil comprising a primary winding and a secondary winding, a current limiting resistance connected in series with the primary winding and a contact breaker, wherein there is provided means which shunt said current limiting resistance for a predetermined time at each closure of the contacts of said contact breaker.