Secondary-Simultaneous Ignition Analysis - Launch X-431 User Manual

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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 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.

4.4.2 Secondary-simultaneous ignition analysis

The following connection should be made before performing this function:
1. Power the Scopebox on: Power is provided to the Scopebox in either of the following ways:
• Power adapter: Insert one end of the power adapter into the Power interface of the Scopebox, and the
other end to the AC outlet.
• Battery clamps cable: Plug one end of the power adapter into the Power interface of the Scopebox,
and then clamp the other two terminals to the vehicle's battery (Red to +, and Black to -) respectively.
2. Connect the B-shaped terminal of the data cable to the Scopebox Data I/O port, and the other end to the
Data I/O port of the USB hub.
3. Plug the BNC end of secondary ignition pickup into CH1/CH2/CH3/CH4 channel of the Scopebox, and
connect the high-voltage clip to high-voltage line, and crocodile clips to ground.
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Fig. Ignition-1
Station
User's Guide
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