B.7 ignition outputs, B.7.1 constant duty vs. constant charge – Haltech E6X Manual DOS Version User Manual
Page 108

E6X Manual
108
Each coil igniter will have its own trigger. If using direct fire, a Home signal is needed for
trailing ignition to be generated.
Distributor
Direct Fire
Output
Function
Function
INJ1
Fuel (Primary)
Fuel (Primary)
INJ2
Fuel (Secondary)
Fuel (Secondary)
IGN OUT
Leading Spark
Leading Spark (both)
IGN 2
Trailing Spark
Trailing Spark front rotor
IGN 3
Digital Output
Trailing Spark rear rotor
B.7 Ignition Outputs
The ignition outputs of the ECU are designed to provide the appropriate signal to drive an
ignitor. The ECU is capable of driving either smart (constant duty) or dumb (constant charge)
ignitors.
WARNING:
UNDER NO CIRCUMSTANCES SHOULD THE IGNITION OUTPUTS
OF THE ECU BE USED TO DRIVE THE COILS DIRECTLY. THE
IGNITION OUTPUTS OF THE ECU ARE INCAPABLE OF SINKING
SUFFICIENT CURRENT TO GENERATE SPARK AND WILL
SIMPLY FORCE THE IGNITION DRIVERS INTO SHUTDOWN
B.7.1 Constant Duty vs. Constant Charge
Constant Duty ignitors contain circuitry that will optimise the dwell for the next ignition and
consequently the ECU only needs to provide a signal that has a constant duty cycle and a
timed edge for ignition. A constant duty ignition signal will appear as below:
A constant charge ignitor requires the ECU to control dwell as well as ignition timing, the
dumb ignitor as it is commonly referred to is basically just a high current switch for the coil.