Abstract: The combination of integrated injection logic (I.sup.2 L) and linear circuitry permits fabrication of a highly dense analog-to-binary coded decimal (A-to-BCD) converter. The heart of the A-to-BCD converter is a linear-I.sup.2 L plurality of high density variable current sinks which are proportional to each other in combination with I.sup.2 L gating techniques. These variable current sinks, when used in combination with the I.sup.2 L constant current sources, current sensing means, and I.sup.2 L logic, provide a highly dense A-to-BCD converter.

Abstract: In fuel injection ignition systems, it is necessary to provide control of the open time of the fuel injector valves which varies with the engine speed. However, for efficient operation with a minimum of pollution, the relationship of valve open time to engine speed is not a simple relationship, and factors other than engine speed are involved. It has been found that the open time should change with engine speed by steps not directly related to engine speed. This can be accomplished by providing a waveform which varies with time across a capacitor by a regulator system which controls both increase and decrease of the voltage across the capacitor. This voltage waveform, which varies with time and is independent of engine speed, can then be combined with a ramp voltage initiated at a particular point of rotation of the engine at the time the injector valves are opened.