Phoenix Pro User Manual
117
voltage was sensed and increased sharply
2) Ignition voltage: secondary coil voltage overcome the damper of high voltage
line, 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 inductance
voltage of ignition coil maintains the conduction of secondary circuit
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 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
angle 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.
13.2 Secondary-simultaneous ignition analysis
Connections: Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3
/CH4 channel of Scopebox, then connect the high-voltage clip to high-voltage
line, and crocodile clips to ground.
Connection as shown in figure 13-2:
