Abstract:
A digital ignition system is disclosed including a precision angular position sensor within the engine distributor or in cooperation with another rotary engine part providing accurate timing information applied to gating means selectively passing bursts of triggering pulses having a 7-to-1 duty cycle ratio. The bursts are applied to a driver circuit providing power amplification energizing the coil primary. An alternative mode is also disclosed simulating a conventional make and break ignition system for a service mode. In the service mode, a single pulse is issued to the coil upon the first pulse of the pulse burst after the angular position sensor senses that a cylinder firing operation is required. Thus, ordinary timing and diagnostic instruments may be used during the service mode to accurately establish ignition timing during normal, burst mode operation. A distributorless embodiment is also disclosed in which individual cylinder timing is obtained from individual disk tracks carrying a plurality of circular tracks between individual light sources and sensors. Each cylinder has its own high voltage system, the triggering pulses being directed selectively thereto by gates controlled by timing information from the disk angular position. A plurality of disks may be used for a more rigid and reliable structure.