Ignition Trigger Input - Block H


        In this block we can either accommodate a Hall effect type of input (0 to => 5 volt) pulse train or a low level input from a magnetic style pickup.  The upper portion of the circuit will accept any threshold crossing signal just like the CAM Index (Block G).  The lower portion uses an LM1815 Adaptive Variable Reluctance Sensor Amplifier.  This amplifier will center on a low level signal generated by a magnetic pickup device.  The output of either circuit can be directed to U15D and the MPC555 Microcontroller.