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cop voltage and current

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by whburling, May 8, 2019.

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  1. whburling

    whburling Junior Member

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    I have a 2014 prius plugin.

    I would appreciate knowing the primary and secondary voltages of the cop (coil over plug) feeding the sparkplug. I would also appreciate knowing the secondary current.

    my goal is to create a voltage divider that I can use to view my secondary cop voltage and current
    on my lab(not car) oscilloscope. I will probably make the voltage divider out of two capacitors vs using
    a resistor voltage divider.

    to capacitively connect to the secondary I was thinking of using my inline spark checker extension
    that connects to the spark plug in the head and then connect the extension to the cop via a coil tester
    light via a silicon wire which is about 12 mm thick. I was then going to clamp onto the outside of the
    silicon wire with a T clamp which runs to my voltage divider and then to my bnc connector that connects
    the signal to my scope. I am not sure how i am going to measure the current other than maybe indirectly through the primary power lead going into the cop.

    any advice is welcome.

    I am guessing (no facts...just pure guess) that the voltage gets as high as 30,000 volts and that the current is much less than ma.

    Thank you for responding.

    bil
     
  2. bisco

    bisco cookie crumbler

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    why?
     
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  3. Raytheeagle

    Raytheeagle Senior Member

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    You’re not supposed to ask that question :p.
     
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  4. Elektroingenieur

    Elektroingenieur Senior Member

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    Sample waveforms for the ignition (IGT; ECM to igniter) and ignition confirmation (IGF; igniter to ECM) signals are given in the Repair Manual (more info); see the procedure for diagnostic trouble codes P0351 through P0354. There isn’t any information about the primary or spark currents or secondary voltage, however; presumably it’s not expected that a technician would need to measure these.

    I have no comment on your measurement setup. If you haven’t already, you may find it helpful to review SAE J973 JUN2013, Ignition System Measurements Procedure. (If you don’t want to pay $81 for a copy, find a university library that subscribes to the SAE MOBILUS service.)
     
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  5. QuantumFireball

    QuantumFireball Active Member

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    Are these not called "coil packs" in the US? I know "coil over plug" as the method of ignition, but not for the name of the actual item.
     
  6. whburling

    whburling Junior Member

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    Morning John !

    Unfortunately, being an engineer, I love looking at data. Your view that Techstream offers enough
    data is a valid point. If I suspect a bad cop, the software will id my problem.

    But as mentioned, I would like to look at the oscilloscope traces to view what is happening at
    the time the coil discharges its energy and for the remainder of the spark cycle. For some reason
    the traces interest me.

    I am afraid that I may damage my non-auto scope with the high voltage. That is why i am seeking
    the information I am asking in this forum. Interestingly I found it difficult to find this information
    for any car manufacturer. I appreciate that spark plug gap defines the voltage (The coil will keep increasing the voltage until a discharge occurs), but with a manufacture's defined gap, that voltage
    should be fairly well defined. Maybe the lack of information on coil voltage at time of discharge indicates I do not understand something that would be nice to know (to hell with fixing the car).

    so please put up with me...You are correct, as most always, that I really do not need to go this far.

    Have an exciting day !
     
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  7. whburling

    whburling Junior Member

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    Wow !!!!! Thank you for being so helpful. I especially appreciated your reference to "Ignition System Measurements Procedure". I respect your approach. I never thought to look at SAE procedures. I should take that approach with future questions. Brilliant. Thank you for taking the time to respond with an answer that is very helpful.
     
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  8. Elektroingenieur

    Elektroingenieur Senior Member

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    You’re welcome.
    Some generic values, which are unlikely to apply to Prius cars, but at least give an idea of the likely orders of magnitude of the various parameters, are given in in Bosch’s Gasoline Engine Management: Systems and Components book (Springer, 2015), on page 175:

    Primary current (I₁): 6.5...9.0 A
    Charging time (T₁): 1.5...4.0 ms
    Secondary voltage (U₂): 29...35 kV
    Spark duration (Tsp): 1.3...2.0 ms
    Spark energy (Wsp): 30...50 mJ, up to 100 mJ for gasoline direct injection
    Spark current (Isp): 80...115 mA
    Resistance of primary winding (R₁): 0.3...0.6 Ω
    Resistance of secondary winding (R₂): 5...15 kΩ
    Number of turns in primary winding (N₁): 150...200
    Number of turns in secondary winding (N₂): 8000...22,000​
    SAE J139 JUN2014, Ignition System Nomenclature and Terminology, uses “coil-on-plug” to refer to the ignition system design. Toyota’s term for the parts is “ignition coil assembly.”
     
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  9. whburling

    whburling Junior Member

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    wow. again! Thank you for your generosity. It takes time to research this stuff. to type it out.
    I know you guys don't like emotion....but I feel so grateful. I wish I knew how to return the
    generosity. I just don't know enough.

    thank you. Thank YOU.

    bil
     
  10. whburling

    whburling Junior Member

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    Elektroinengieur !!! It is apparent that either you have exceptional research skills or you
    already had an interest in ignition systems. If the latter, can you share some interesting stories
    that you might have had while working in that field? bil
     
  11. ChapmanF

    ChapmanF Senior Member

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    As far as I can tell, it's the former. Try some other obscure question that's not about ignition systems and see what happens.

    Being connected in some way to an organization that has a good research library and access to paywalled standards databases can definitely make the research easier.
     
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  12. whburling

    whburling Junior Member

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    ChapmanF......you have a wonderful sense of humor......

    I am truly overwhelmed by people trying to help me....and people having a sense of humor.
    This kind of generosity does not happen to me very often. Thank you all
     
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