WAV E F O R M
UNIVERSAL KV PROBE
UNIVERSAL COP WAND
Fig. 2: We can use a single trace example from a DSO on the lab scope side and view secondary one cylinder at a time on a DIS system or on an engine equipped with COP coils. Here, we use the universal KV probe on the secondary lead. Fig. 3: Here, we use the COP wand instead of the KV probe.
quired. This is a valuable function for a TPS sweep check or by viewing the O2 sensor activity. 4. TRIGGER SOURCE: You must tell the DSO what channel input that you want the scope to use for a trigger input. If you are using a single channel, for example channel 1, the scope’s trigger input would need to be set for that channel. If you are doing a dual trace test, for example the CKP and CMP inputs, you can select either channel input for a trigger source. We will demonstrate these fundamentals during our screen captures. These four fundamental rules once learned will be etched into your long term memory. Measurements on scope waveforms are often a necessity. On the vertical scale, there are eight squares or major divisions. Inside each major division are five minor divisions. The vertical major and minor divisions are used to measure a voltage value. If the voltage setting is 5 volts per division, then the ability to see 40 volts on the screen is available. If using a universal secondary KV probe or a COP wand with attenuation factors of 1,000 to 1, then a 1 volts per division becomes 1 KV per division. This is a popular voltage per division setting when looking at a secondary event with a DSO. The horizontal scale is used
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ANATOMY OF A SECONDARY IGNITION WAVEFORM
Fig. 4: It is vitally important to know the critical points of the waveform. More diagnostic information is available by viewing a secondary waveform.
ASP | JUNE 2021
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