LAUNCH X431 GDS Scopebox Manual
6) Contact point close: The current flow into primary coil, the
primary coil oscillates due to the mutual inductance.
Primary ignition waveform
Section a shows the voltage oscillation on the primary circuit due to
the magnetic induction of spark in the duration;
Section b shows the damped oscillation generated by remaining
magnetic fiel
d energy after the spark;
Section c shows the period of primary coil charging.
Seen from
the waveform, the amplitudes of breaker contact closed
angle, break a
ngle and breakdown voltage and spark voltage are
very clear, besides, the spark delay period and two oscillations can
also be tested. For the ignition system without faults, compared with
the whole cycle, the contact closed angle just 45%-50%
(four-cylinder), 63%-70% (six-cylinder), or 64%-71% (eight-cyliner);
the breakdown voltage is over 15kv; the spark voltage is about 9kV,
the spark period is greater than 0.8ms. If these values or waveform
are abnormal, it means there is fault or the system needs to be
adjusted.
4.2 Primary-simultaneous ignition analysis
The Figure 4-3 below shows the valid and invalid ignition waveforms.
Under the working status of valid ignition, the breakdown voltage
and spark voltage are higher due to the cylinder was filled fresh
combustible mixture gas, which has a lower ionization level; vice
versa; the above-mentioned shall be distinguished during testing.
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