Fuel injection pulse duration - is computed by full adder, m stage parallel shift register and exclusive OR:gates

摘要

The computational circuit determines the fuel injection pulse period for an internal combustion engine. The pulse duration is modified by a correction factor based upon such parameters as engine speed, and intake vacuum. a full adder stage (1) receives a serial input and generates an output over an EXCLUSIVE - OR gate (7b) to a shift register input (2). The shift register consisting of M stages is clocked at a predetermined frequency (fs). The shift register cycles at a rate of fB = fs/M to generate an output that is transmitted to the full adder stage. A O or 1 signal to the EXCLUSIVE - OR gates (7a, 7b) causes the process to add or subtract. The output from the circuit (S1) is of frequency proportional to the binary input.