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

Page 108

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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.

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