Abstract: A digital advance control system of the type including a digital computer which receives input data of various engine operating parameters including the number of pulses corresponding to the ignition angle from a tachometer device in which the data from the tachometer device is to be interpolated. The data to be interpolated is applied to an attenuator circuit which includes a subtracter which receives the higher order bits of the data and a reversible counter whose higher order bits are also applied to the subtracter. The output of the subtracter is applied to a preselection counter or a binary rate multiplier which controls the application of clock pulses to the reversible counter.

Abstract: A control circuit for delivering control signals to interrupt admission of the fuel-air mixture in the low speed and idle circuit of the carburetor of an internal combustion engine. The control circuit is operated according to the engine operating conditions. The control signal is delivered in response to comparison of a signal whose level is representative of the amplitude of the variations, i.e., the absolute value of the variations in the duration of an engine cycle, with a substantially periodic signal to generate a pulse-shaped signal. The pulses have a relatively narrow width when the amplitude of the variations is great, and a larger width when the amplitude of the variations is smaller.

Abstract: A control circuit for delivering control signals to interrupt admission of the fuel-air mixture in the low speed and idle circuit of the carburetor of an internal combustion engine. The control circuit is operated according to the engine operating conditions. The control signal is delivered in response to comparison of a signal whose level is representative of the positive or negative variations in the duration of an engine cycle with a substantially periodic signal to generate a pulse shaped signal. The width of the pulses increases when the vehicle is accelerating and decreases when the vehicle is decelerating.

Abstract: Apparatus and method for producing a control signal for a fuel injection system of a combustion motor wherein operating parameters of the motor are measured in analog form and alternately converted into digital information, the digital information is counted and applied to produce coded words each corresponding to an operating parameter, the coded words are applied to a programmed memory to produce output words and the output words are converted into the control signal.

Abstract: A solenoid valve is provided for controlling fluid communication in a passage defined between a first and a second orifices. A valve seat is defined in the passage and a valve member is adapted to be urged into contact with the valve seat to interrupt fluid communication between the first and second orifices. A coil and a fixed core control movement of the valve member in response to energization of the coil. The valve member is attached to a magnetized rod which is coaxial with the core. When the coil is not energized, the magnetized rod is normally attracted toward the fixed core in response to induced magnetization of the latter, to keep the valve member away from the valve seat. In response to energization of the coil, magnetization of the core is reversed and the rod 28 is repelled so that the attached valve member is urged into contact with the valve seat.

Abstract: Method and apparatus for producing a control function signal of a given duration for a fuel injection system of an engine in which a word, or number, corresponding to the desired control function is set into a first counter to define a first number of pulses to be counted. The frequency of the pulses applied to the counter is controlled in response to an operating parameter. A second counter counts a second number of the pulses and the two numbers of pulses define two time intervals which are added. A third counter counts a signal representative of the time interval produced by the addition of the two time intervals and a predetermined number of said signals are counted by the third counter to define the duration of the control signal.

Abstract: Method and apparatus for producing a control function signal of a given duration in which a word, or number corresponding to the desired control function is set into a first counter to define a first number of pulses to be counted. A second counter counts a second number of pulses and the two numbers of pulses define two time intervals which are added. A third counter counts a signal representative of the time interval produced by the addition of the two time intervals and a predetermined number of said signals are counted by the third counter to define the duration of the control signal.

Abstract: A tachometer and angular progression measuring system for a rotary device of the type including a pickup for producing a pulse each time the rotary device has rotated a given angle which includes a source of first pulses of a first frequency synchronized to the pulses from the pickup, means for counting the number of first pulses occurring between two successive pickup pulses, a source of second pulses of a higher frequency than the first pulses, and a means for producing output pulses whose period between two successive pulses correspond to a number of periods between successive second pulses depending on the number of first pulses counted by the counting means.

Abstract: A circuit for controlling transient occurrences in an electronic fuel injection system in which the occurrence is sensed and used to produce auxiliary injection signals which are combined with the main injection signals from the injection system computer. The time of production and the duration of the auxiliary signals can be controlled in response to operating conditions of the engine.