Haltech E6S Manual de usuario descargar pdf (Pagina 128)

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Figure E7. Illustrate constant duty against frequency

A "dumb" igniter is one that does not perform any sort of dwell control, thus input signal

directly controls switching of the coil. A constant duty cycle signal is not the best signal to use

with this sort of igniter as it will overheat the coil at low frequencies (ie low revs), and not

allow enough charge time at high frequencies (ie high revs) Since the coil charge time remains

approximately the same regardless of frequency, it is appropriate for the ECU to constantly

charge the coil for exactly that time before firing.

The coil’s charge time can be determined from the coil -ve signal. When the coil switches on,

voltage drops to zero. As the coil charges, the voltage rises slightly, until a sharp rise where

the igniter current limits. Leaving the coil switched on any longer will not increase the energy

in the coil or of the spark. See figure E8.

When the ignition firing frequency is high, there will not be enough time to charge the coil

completely. After firing the spark, the E6S will wait for a short period, then switch the coil on

again, regaining much of the lost energy in “ringing”. This break time should normally be 1 to

1.5ms.

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Haltech E6S Manual de usuario Pagina 128