Ignition timing adjustment device preventing engine knock - uses product of two counters receiving knock signal and speed signal respectively

摘要

The device responds to a knock signal to shift the firing point. The knock signal indexes a counter (13) in the forwards direction, the counter being indexed in the reverse direction by adjustment of the engine operating parameters. A second counter (14) stores a value corresponding to the engine revs, with the product of the count values held by the two counters (13,14) determining the magnitude of the timing adjustment. Pref. the two counters are coupled to a multiplier (15), its output fed to a third counter (16), which is read-out in response to the ignition pulses with a preset delay. The third counter (16) may be indexed backwards by a pulse generator to provide an output pulse when it reaches zero. The device is used as an attachment to an electronic ignition timing control.