Primary voltage on a waste spark distributorless ignition

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Re: Primary voltage on a waste spark distributorless ignitio

Postby Steve Smith » Wed Jul 09, 2014 1:33 pm

Well here we are with the GT86 ignition waveform. Unfortunately I could not gain access with the current clamp with the time constraint but I have got the IGT signal in relation to secondary activity. As a result of testing we will now make a break out lead for the igniter as I can see some real value given the igniter location.

The waveform demonstrates the point at which the primary is switched on revealing the "Polarity Peak" and the point where the primary is switched off.

Here we can see the oscillations you mentioned as the initial high voltage is utilised to jump the electrode gap, followed by the dissipation of this voltage throughout the secondary windings as the spark continues to flow across the electrode gap (Burn time)

Finally the "coil oscillation at the end of the burn time.

IGT-COP SECONDARY.jpg


Toyota_GT 86_2012_Petrol_20140709-0001.psdata
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Re: Primary voltage on a waste spark distributorless ignitio

Postby AdvTechTS » Wed Jul 09, 2014 1:57 pm

That is great and it would be handy if some of these newer systems could be added to the 'in tool' library ;)

There is only one last thing that I don't understand about my waveform and that is why the burn time is at 0 Volts?
Has it got anything to do with how I have set up the scope?
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Re: Primary voltage on a waste spark distributorless ignitio

Postby Steve Smith » Thu Jul 10, 2014 2:55 pm

Thank you again for the feedback and duly noted about the "tool library" (Help files) which will be increasing in size with revisions and additions as we all progress.

Regarding the burn time at zero volts, remember how we are testing and measuring the secondary firing voltage. (Using a near non contact, capacitive pick up COP probe or pick up leads)

The beauty of the capacitive pick up is that they measure the “Electrical field” around a component.

Using the capacitive pick up enables you to sense this field around non-conductive components such as “Coil on Plug-COP” units.

The strength of the electrical field is dependent upon the current flow and activity through the component. Given we do not have a hard wire connection to the secondary coil we are reliant upon the electrical field to produce our signal/waveform.

Hence, we see the "Polarity peak", some activity during the dwell period, the rapid induction into the secondary, oscillations, burn time, and coil ringing as we then climb to our zero volt point to start all over again.

In the image I have posted, the scale has been increased 3 times to provide more detail, can you try this technique with your capture?

Take care......Steve
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Re: Primary voltage on a waste spark distributorless ignitio

Postby AdvTechTS » Thu Jul 10, 2014 3:02 pm

Regarding the burn time at zero volts, remember how we are testing and measuring the secondary firing voltage. (Using a near non contact, capacitive pick up COP probe or pick up leads)


This is what I was trying to grasp!!!

Thank you again for all of your support, top product with fantastic support :D
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