摘要 |
An internal combustion engine operation timing control uses a programmed read only memory to produce a multibit digital signal used to determine the instant of operation. There are two inputs to the ROM, one of which is from a speed counter and the other of which is from another engine parameter transducer. The digital output of the ROM is applied to a timing counter for conversion to a time duration by clocking out timing pulses. The same master clock is used for clocking both the speed counter and the timing counter, a frequency divider programmed in accordance with the 3MSBs of the speed counter is used to reduce the clock frequency as the count in counter increases during speed computation, the same divisor remaining in action during the timing operation. |