Method and apparatus for obtaining an automatic ignition advance in automobile internal combustion engine

Claim 1

In combination with an internal combustion engine, apparatus comprising a current generator having a current output proportional to speed of rotation of the engine, said current generator supplying an integrator which produces a sawtooth output signal V 1 , means for providing an output signal V 3 dependent on at least one of the internal combustion engine operation parameter, means adding signals V 1 and V 3 to produce a voltage V 1 + V 3 proportional to angular offset α, means feeding voltage V 1 + V 3 to one input of a pulse generator, a tachometric generator supplying a voltage V 2 proportional to the speed of rotation of the engine to another input of the pulse generator, said pulse generator producing a pulse controlling engine ignition when the voltage V 1 + V 3 coincides with voltage V 2 consideration being given to a proportionality constant, said pulse generator comprising comparator means having input terminals connected to receive voltages V 1 + V 3 and V 2 for delivering a signal to the ignition device when said voltages are coincident by means of an amplifier; and further comprising a monostable multivibrator connected to apply an output signal thereof to the ignition device directly by means of the amplifier, and a switching circuit connected on one hand to the output of the amplifier and on the other hand to at least one of the inputs of the comparator, said switching circuit being responsive to the triggering of ignition pulses to reinforce said pulses thereby isolating the circuit from the effects of spurious signals.