Launch X431 Scopebox - Page 99

LAUNCH X431 GDS Scopebox Manual
1) Contact break point: the primary circuit of ignition coil cut off, the
secondary voltage was sensed and increased sharply
2) Ignition voltage: secondary coil voltage overcome the damper of
high voltage lin
e, the contact breaker gap and the spark plug gap
to release magnetizing energy, 1-2 section is the breakdown
voltage
3) Spark voltage: For the capacitor discharge voltage
4) Ignition voltage pulse: For the charge and discharge sections
5) Spark line: The inductance discharge process, i.e. the mutual
inductan
ce v
oltage of ignition coil maintains the conduction of
secondary circuit
6) Contact point close the current flow into primary coil, the primary
coil oscillate
s 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 show
s the damped oscillation generated by remaining
magnetic field energy after the spark;
Section c shows the make contact magneting period of primary coil.
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);