Wiring-I'm Confused

[DewCatTea-Bob]

That's one terminal representing one end of the secondary coil. The metal can which is conductive is the second terminal, that is to say the other end of the secondary coil wire.

Giday Jim, the secondary circuit is from the center terminal to the positive primary terminal. The case is not connected to the windings.

Thanks Harvey. I stand corrected.
Ducatikid, I was wrong about how to measure the high voltage winding's resistance. You must measure between the high voltage cap and one of the primary terminals.

____ I'm sort-of surprised/disappointed that no-one has contested or at-least commented about this exchange. ...
__ Since Jim should have the same-type of 'Green-label' HT.coil on his Mark-III, I just assumed that he had KNOWN of what he had stated (and-so didn't consider the actual-case until Harvey posted his statement).
It seems like somebody (besides myself) would've cared to follow-up on that which Harvey has stated,, not just because he's obviously not in reference to the so-called "AC.ignition-coil" (which does-not have a "positive primary terminal"), but more-so because his suggested circuit-pathway for the HT.secondary would have it's HT.sparking-juice passing-through the battery (and whatever other system-loads happen to-be in parallel-circuit with the battery, such-as lights), on battery-powered models (which employ a common DC.ignition-coil).
So apparently Harvey must've been in reference to a common-ign.coil properly connected-up to a POSITIVE-ground system. _ (And certainly-not in reference to a 160-type ign.system, of-which it's ign.coil has one of it's terminals directly-grounded !)
__ I don't happen to be fully aware of exactly how the internals of the Green-label HT.coil are actually connected-up within, but Harvey is certainly in reference to a common-type DC.ignition-coil (which is actually a HIGH step-up 'auto-transformer'), of-which BOTH the 'secondary' AND the 'primary' SHARE the secondary's HT.current-flow !
__ In regards to the standard-DC.type of ign.system, the question of exactly where the spark-juice disappears-to (after entering the cyl.head from the spark-plug), when the secondary is-not directly-grounded to/within the HT.coil-casing (and so-thus it's not obviously presented with a direct ground-circuit/connection back-into the HT.coil's secondary,, ought-to be worthy of further discussion ! _ So if anyone cares to, then please ask about it.
____ I briefly attempted a search of the internet to find some related layout-data concerning the internal-workings of such rather common Italian-type AC.powered ign.coils but, I have yet to find any of such. _ However I did find lots of such related diagram-pix on the more common standard-type of DC.powered HT.coils, like that which Harvey must've been in reference-to - (see top posted-pic, [which is somewhat short-sighted on it's external-circuit details]),, and also a pic.example of a much less common NONauto-transformer type of DC.ignition-coil setup, which depicts the rather separate type of primary/secondary relationship that's much-more*like that which Jim had expected, (* except that the opposite-end of the secondary goes-to ANOTHER spark-plug, instead-of directly to ground within the HT.coil's metal-casing).
I've also included a pic which attempts to display the physical-arrangement of the primary & secondary windings within a common std.type DC.powered auto-transformer HT.coil.


Enlightened-Cheers,
-Bob

[Ducatikid]

Bob, I asked the builder about the chance of the alt/mag being incorrectly timed to the crank. He said "it is possible, but, he's pretty sure this isn't the case on my engine". He still is asking if I have tried a new HT coil that is specifically made for an alt/mag system....he's sure that's my problem. I asked him to send me one I could test with as I haven,t found one that is correct in my area to try. I think my original green label coil is ok, but, the system doesn't spark with it in place. So I'm waiting for the test coil...........Until later.....Tom

[Ducatikid]

Bob, No. 2 Question.....I have a friend who said my problem was with my condenser at the points plate? I have connected my meter to the lead wire from the points/condenser and ground. with slowly turning the engine over I can see the points open and close. Is there any other tests I need to do to make sure everything is ok at the points/condenser??? It is suppose to have continuity (to ground) when the points are closed , right? Tom

[DewCatTea-Bob]

[quote= Ducatikid ... I asked the builder about the chance of the alt/mag being incorrectly timed to the crank. He said "it is possible, but, he's pretty sure this isn't the case on my engine". "

____ I wonder how he could be so "pretty sure", when it was he-himself who thought that the manual-book (which he had consulted), was wrong about the stator-wiring !? _ In other-words, if he went-by some book which didn't cover the 160-type alt.stator,, then-also, he had likely then used that same book's rotor-timing specs, which wasn't meant to cover the 160, and-so rather (incorrectly) timed the mag.rotor to the crankshaft according-to the model-data which his book DID cover.



" He still is asking if I have tried a new HT coil that is specifically made for an alt/mag system....he's sure that's my problem. "

____ Unless your stock-coil has any obvious physical-damage, I-myself am rather doubtful of his conclusion.
__ There's actually no such thing as an 'AC.ignition-coil', as ALL HT.coils work off-of either steady-DC, or a single-pulse of DC (from the available DC.pulses of AC), in order to create an ign.spark. _ So mainly, the only internal-difference ought-to be with the primary-gauge & turns-ratio. _ So in effect, when you tried-out the new "6v" HT.coil, you've thus pretty-much already tried the test which he wants you to try.



" I asked him to send me one I could test with as I haven,t found one that is correct in my area to try. "

____ Such an ign.coil shouldn't be too hard to find, as most-all small-engined Italian-motored two-wheel vehicles employ such magneto-type 'energy-transfer' ign.systems, (as well as quite a few small Honda-models). _ But I don't think that trying such will make any notable difference, anyhow.
__ To learn whether your ign.system is at any fault, you should try-out the test which I've already suggested (on the previous-page)... Do you not have a filtered-type transformer/power-adapter which can provide you with an alternate DC.power-source (for powering your ign.system, in-place of your 160's alt.output) ?



" I think my original green label coil is ok, but, the system doesn't spark with it in place. "

____ That your other/new HT.coil doesn't do-so EITHER, should tell you something.



" I have a friend who said my problem was with my condenser at the points plate? "

____ So if that new part is any suspect, then have you not yet tried-for obtaining any ign.spark, with that condenser removed ?



" I have connected my meter to the lead wire from the points/condenser and ground. with slowly turning the engine over I can see the points open and close. "

____ I gather-that you mean that your ohm-meter goes back & forth from zer0 to near infinity, as the contact-points shut & separate ?
If so, that was indeed a good test to make-sure that you have no shorts to ground (that could've been killing that ign.circuit) !



" Is there any other tests I need to do to make sure everything is ok at the points/condenser??? "

____ Yes, you could make-sure that the plate which they're both mounted-to, is indeed fully grounded to the motor-casing, (with no insulating corrosion).



" It is suppose to have continuity (to ground) when the points are closed , right? "

____ If by "It", you're meaning the terminal-end of the points-wire for the ign.coil,, then certainly 'yes', indeed !


Hopeful-Cheers,
-Bob

[Harvey]

That's one terminal representing one end of the secondary coil. The metal can which is conductive is the second terminal, that is to say the other end of the secondary coil wire.

Giday Jim, the secondary circuit is from the center terminal to the positive primary terminal. The case is not connected to the windings.

Thanks Harvey. I stand corrected.
Ducatikid, I was wrong about how to measure the high voltage winding's resistance. You must measure between the high voltage cap and one of the primary terminals.

I'm sort-of surprised/disappointed that no-one has contested or at-least commented about this exchange. ...
__ Since Jim should have the same-type of 'Green-label' HT.coil on his Mark-III, I just assumed that he had KNOWN of what he had stated (and-so didn't consider the actual-case until Harvey posted his statement).
It seems like somebody (besides myself) would've cared to follow-up on that which Harvey has stated,, not just because he's obviously not in reference the the so-called "AC.ignition-coil" (which does-not have a "positive primary terminal"), but more-so because his suggested circuit-pathway for the HT.secondary would have it's HT.sparking-juice passing-through the battery (and whatever other system-loads happen to-be in parallel-circuit with the battery, such-as lights), on battery-powered models (which employ a common DC.ignition-coil).
In regards to the standard-DC.type of ign.system, the question of exactly where the spark-juice disappears-to (after entering the cyl.head from the spark-plug), when the secondary is-not directly-grounded to/within the HT.coil-casing (and so-thus it's not obviously presented with a direct ground-circuit/connection back-into the HT.coil's secondary,, ought-to be worthy of further discussion ! _ So if anyone cares to, then please ask about it.

Well yes that is how the circuit goes. The electron flow is from the center terminal end, of the secondary winding, across the resistance of the plug gap to ground. Then flowing through all the connected, grounded circuits, back to the Positive terminal, and the opposite end of the secondary winding. This includes, the battery, lights, stereo, etc.
As for the “HT.sparking-juice”, that High voltage of about 12kv from the secondary, only exists across the resistance of the plug gap. The rest of the circuit only flows battery voltage at about 2amps.

So apparently Harvey must've been in reference to a common-ign.coil properly connected-up to a POSITIVE-ground system. _ (And certainly-not in reference to a 160-type ign.system, of-which it's ign.coil has one of it's terminals directly-grounded !)
__ I don't happen to be fully aware of exactly how the internals of the Green-label HT.coil are actually connected-up within, but Harvey is certainly in reference to a common-type DC.ignition-coil (which is actually a HIGH step-up 'auto-transformer'), of-which BOTH the 'secondary' AND the 'primary' SHARE the secondary's HT.current-flow !

There is no difference between the two types of coil, the difference is in the way they are powered.. It makes no difference, if the points are on the positive or negative side of the primary windings. The flow will still be turned off, to produce the high voltage.

Looking at the first diagram of a battery powered coil, that you posted. If the battery is removed and replaced with alternator power, with the blue wire feeding the coil, it is the same as the Ducati Magneto system. So at the time of producing the spark, both coil systems are feed a positive voltage potential, to have peak current flowing, that the points can switch off. It makes no difference if the points are on the positive, or negative side of the coil, the result is the same.

____ I briefly attempted a search of the internet to find some related layout-data concerning the internal-workings of such rather common Italian-type AC.powered ign.coils but, I have yet to find any of such. _ However I did find lots of such related diagram-pix on the more common standard-type of DC.powered HT.coils, like that which Harvey must've been in reference-to - (see top posted-pic, [which is somewhat short-sighted on it's external-circuit details]),, and also a pic.example of a much less common NONauto-transformer type of DC.ignition-coil setup, which depicts the rather separate type of primary/secondary relationship that's much-more*like that which Jim had expected, (* except that the opposite-end of the secondary goes-to ANOTHER spark-plug, instead-of directly to ground within the HT.coil's metal-casing).
I've also included a pic which attempts to display the physical-arrangement of the primary & secondary windings within a common std.type DC.powered auto-transformer HT.coil.


Enlightened-Cheers,
-Bob

Cheers n beers. Harvey.

[DewCatTea-Bob]

____ Welcome-back to this thread-post discussion Harvey ! _ Although I had hoped for others as well, to join-in on this topic-matter.
__ You've brought-up a couple of differing topics which I wish to further cover, somewhat more thoroughly.

It seems like somebody (besides myself) would've cared to follow-up on that which Harvey has stated,, not just because he's obviously not in reference to the so-called "AC.ignition-coil" (which does-not have a "positive primary terminal"), but more-so because his suggested circuit-pathway for the HT.secondary would have it's HT.sparking-juice passing-through the battery (and whatever other system-loads happen to-be in parallel-circuit with the battery, such-as lights), on battery-powered models (which employ a common DC.ignition-coil).
In regards to the standard-DC.type of ign.system, the question of exactly where the spark-juice disappears-to (after entering the cyl.head from the spark-plug), when the secondary is-not directly-grounded to/within the HT.coil-casing (and so-thus it's not obviously presented with a direct ground-circuit/connection back-into the HT.coil's secondary,, ought-to be worthy of further discussion ! _ So if anyone cares to, then please ask about it.

Well yes that is how the circuit goes. The electron flow is from the center terminal end, of the secondary winding, across the resistance of the plug gap to ground. Then flowing through all the connected, grounded circuits, back to the Positive terminal, and the opposite end of the secondary winding. This includes, the battery, lights, stereo, etc.
As for the “HT.sparking-juice”, that High voltage of about 12kv from the secondary, only exists across the resistance of the plug gap. The rest of the circuit only flows battery voltage at about 2amps.

____ Does anybody-ELSE have any problem with any of this statement-claim by Harvey ?
__ While I-myself could believe that it's possibly possible for a very-FEW of the actual/very-same electrons (which had jumped the spark-gap) to chance ending-up passing-through the battery on their way back to the HT.coil-secondary, I really don't see THAT circuit-pathway as being the PRIME circuit-way for satisfying the secondary's electricity-circuit requirement.
But before I go-on to explain what the real HT.secondary circuit-pathway ACTUALLY-is, I'd first like to be entertained by how you -(Harvey) squirm-out from under the shadows which I'm next going to cast on YOUR claimed-theory (for the HT.secondary circuit-pathway). ...
__ So Harvey, here's a couple of 'what-IFs' for you to explain (so as to attempt to keep YOUR claimed-theory afloat)...
Firstly, it seems that you expect a battery to be part-of (or at least involved with) an ignition-system's HT.secondary-circuitry current-flow,, so-then how would the HT.secondary's electrical-circuit current-demand still become satisfied IF the battery were to happen-to go off-line (due-to a busted wire-terminal), whilst the lights & horn (and stereo & air-conditioner, etc) all happen to be turned-off ? _ (Please don't simply say that such circumstance would then kill the ign.spark, [as it's KNOWN that it would-NOT].)
Secondly, what-IF the spark-plug's gap happened to become reduced to near negative-clearance, what then would be the resulting-effect of the HT.secondary's HT.current on the battery, etc., (would we then be able to see a HT.spark jumping somewhere inside the battery, or what ?) ?

____ Harvey, please don't get upset at all, as this-stuff is all done in-light of helping us old-guys keep our tickers tickering-along (so-that they don't become all fogged-up from lack of use).

So apparently Harvey must've been in reference to a common-ign.coil properly connected-up to a POSITIVE-ground system. _ (And certainly-not in reference to a 160-type ign.system, of-which it's ign.coil has one of it's terminals directly-grounded !)
__ I don't happen to be fully aware of exactly how the internals of the Green-label HT.coil are actually connected-up within, but Harvey is certainly in reference to a common-type DC.ignition-coil (which is actually a HIGH step-up 'auto-transformer'), of-which BOTH the 'secondary' AND the 'primary' SHARE the secondary's HT.current-flow !

There is no difference between the two types of coil, the difference is in the way they are powered.. It makes no difference, if the points are on the positive or negative side of the primary windings. The flow will still be turned off, to produce the high voltage.

____ Well if indeed there's "no difference between the two types" , then exactly-WHY would there be TWO-types of HT.coils -(the Green & the Red labeled versions) ?



" Looking at the first diagram of a battery powered coil, that you posted. If the battery is removed and replaced with alternator power, with the blue wire feeding the coil, it is the same as the Ducati Magneto system. "

____ Well yes, (probably-so),, at-least as far as the HT.coil's internal-circuitry is concerned.
__ I've finally gotten around to improving that "first diagram" (so that it now indeed correctly/fully reflects the ENTIRE circuit-scheme of the Green-coil ign.system), and have posted it down-below.



" So at the time of producing the spark, both coil systems are feed a positive voltage potential, to have peak current flowing, that the points can switch off. It makes no difference if the points are on the positive, or negative side of the coil, the result is the same. "

____ Wish you had a diagram of-sorts to go along with that which you're meaning to state, (cuz I'm led to think-of more than one concept that your chosen-wording may be meaning to convey).

[Ducatikid]

Bob, No, I don't have a transformer/power adapter or any alternate DC power source. I think the alt/mag is timed wrong. I can't see anything else being at fault here. How much work are we talking here to retime the alt/mag ? Is it something I can tackle or do I need special tools? I see the clutch assembly coming off and then the stator flywheel.....what else is needed??? I don't have a degree wheel if one is needed? Thanks again, Tom

[DewCatTea-Bob]

[quote= Ducatikid ...
" I don't have a transformer/power adapter or any alternate DC power source. "
____ I'd think that most-everyone would have a left-over power-adapter (from some old cell-phone or something), laying-around & waiting for some-day when it may become of some use once-again.



" I think the alt/mag is timed wrong. "

____ It would be a very-unlikely coincidence for a mag.rotor to be exactly miss-timed so as to put-out 'ZER0' power at the very time when the ign.points are set to open !
So more than likely, there IS SOME power being fed into your ign.system, but just not enough to make a spark jump the gap.
So-then how-about closing-up your spark-gap down-to .012" or less, to see if you get any ign.spark THEN ?



" How much work are we talking here to retime the alt/mag ? Is it something I can tackle or do I need special tools? I see the clutch assembly coming off and then the stator flywheel.....what else is needed??? I don't have a degree wheel if one is needed? "

____ All this related matter has been well covered in another thread earlier this year ! _ But before exposing you to all that relatively complex stuff,, how about a picture of your alt/mag.rotor, showing it's timing-mark in it's current timed-relationship to the crankshaft's TDC.position ?


Hopeful-Cheers,
-Bob

[Harvey]

____ Welcome-back to this thread-post discussion Harvey ! _ Although I had hoped for others as well, to join-in on this topic-matter.
__ You've brought-up a couple of differing topics which I wish to further cover, somewhat more thoroughly.

Bob while I am in tune with this statement.

____ Harvey, please don't get upset at all, as this-stuff is all done in-light of helping us old-guys keep our tickers tickering-along (so-that they don't become all fogged-up from lack of use).

I do take exception to the tone of this bit. I write what I believe to be right, to help others, I am not into arguments of ‘I’m right your wrong’, I am happy to explain any of my statements. If you have a theory, on the subject, I would be more than happy to hear it.

But before I go-on to explain what the real HT.secondary circuit-pathway ACTUALLY-is, I'd first like to be entertained by how you -(Harvey) squirm-out from under the shadows which I'm next going to cast on YOUR claimed-theory (for the HT.secondary circuit-pathway).

__ While I-myself could believe that it's possibly possible for a very-FEW of the actual/very-same electrons (which had jumped the spark-gap) to chance ending-up passing-through the battery on their way back to the HT.coil-secondary, I really don't see THAT circuit-pathway as being the PRIME circuit-way for satisfying the secondary's electricity-circuit requirement.
Firstly, it seems that you expect a battery to be part-of (or at least involved with) an ignition-system's HT.secondary-circuitry current-flow,, so-then how would the HT.secondary's electrical-circuit current-demand still become satisfied IF the battery were to happen-to go off-line (due-to a busted wire-terminal), whilst the lights & horn (and stereo & air-conditioner, etc) all happen to be turned-off ? _

We .are talking about a DC system, aren’t we?
Well I don’t know how there will be any secondary current, if the battery is out of the circuit?
The secondary current will flow through the lowest resistance path, even if that involves jumping across the point gap, or across the case to the positive terminal.

Secondly, what-IF the spark-plug's gap happened to become reduced to near negative-clearance, what then would be the resulting-effect of the HT.secondary's HT.current on the battery, etc., (would we then be able to see a HT.spark jumping somewhere inside the battery, or what ?) ?

I think you missed this bit.
“As for the “HT.sparking-juice”, that High voltage of about 12kv from the secondary, only exists across the resistance of the plug gap. The rest of the circuit only flows battery voltage at about 2amps.”.
If the plug gap is zero, there will be no Hi voltage. It is the resistance of the plug gap that causes the voltage to rise, to overcome the resistance. No resistance in the circuit, no ‘HT spark’ to jump anywhere.

____ Well if indeed there's "no difference between the two types" , then exactly-WHY would there be TWO-types of HT.coils -(the Green & the Red labeled versions) ?
" Looking at the first diagram of a battery powered coil, that you posted. If the battery is removed and replaced with alternator power, with the blue wire feeding the coil, it is the same as the Ducati Magneto system. "

As I see in your reply to Ducatikid, It is an Energy Transfer system, and not an Inductive system. This makes a difference in the primary windings of the two. In the inductive system the primary is fed 12V, and the secondary is produced on the collapse of the field. In the Energy system that primary is fed about 250V, and the secondary is produced on the rise of the field. So the primary windings may well be different.

Best I could find on this system.

Cheers Harvey.

[DewCatTea-Bob]

[quote= Harvey ...
" I do take exception to the tone of this bit. "

____ That's of-course not at all intended to be so, Harvey ! _ So the "tone" is only in your ear, and not meant to exist !
I try & expect all my wording to be taken-in neutrally (at worst).
__ I fairly-much appreciate your inputted conceptions, and find them to-be of use for spring-boarding off-of, so-as to launch my-own response-statements, (of which of-course are certainly-not meant to-be out-rightly confrontational or even close to the-like) !
So please excuse any wording that allows you to think otherwise, or-else bring the offensive-wording to-light, and I'll then gladly reword it !
__ Next below is my (possibly offensive) wording which you had quoted in bold-lettering, so-thus I assume that's what you had taken "exception to the tone of".

I'd first like to be entertained by how you -(Harvey) squirm-out from under the shadows which I'm next going to cast on YOUR claimed-theory

____This quoted-wording was just a play-on-words, merely meant to make the post more interesting for others to read. _ And besides, the word "squirm" is-not really much off-base when ya have-to come-up with explanations for related-things that shouldn't really exist, (which of-course I thought would be fairly entertaining).
__ In-place of that particularly chosen posted-wording, I guess I could've instead stated something like: 'I would first like to learn-of your explanations for a couple of possible circumstances which would seem to cast some doubt on your claimed-theory (of how the HT.secondary current-path must flow).'. _ So would THAT wording have been of a more acceptable "tone" for you, (or is that still too-brash as well) ?



" I write what I believe to be right, to help others, "

____ As do I, Harvey,, so-then you shouldn't object if I feel the need to step-in & correct any misconceptions by others, even-yourself,, correct ?
(As I know that I appreciated such, back-when YOU corrected myself when I got exhaust pressure-wave terminologies rather mixed-up in my brief-attempt to explain such.)



" If you have a theory, on the subject, I would be more than happy to hear it. "

____ Are you referring-to exactly WHERE the HT.current goes (onward from the spark-plug), in order to satisfy the HT.secondary's electrical-circuit requirement ?
If-so, I'd think that most anyone like Jim would have the basic-conception to be able to answer that slight mystery,, and-so that's why I've been waiting for someone-else to chime-in with the specific answer. _ As I'm fairly-sure that many others (with the common basic-conception of the workings of a std.type-ign.system), are already fairly well aware of the directly related circuit-operations.

__ While I-myself could believe that it's possibly possible for a very-FEW of the actual/very-same electrons (which had jumped the spark-gap) to chance ending-up passing-through the battery on their way back to the HT.coil-secondary, I really don't see THAT circuit-pathway as being the PRIME circuit-way for satisfying the secondary's electricity-circuit requirement.
Firstly, it seems that you expect a battery to be part-of (or at least involved with) an ignition-system's HT.secondary-circuitry current-flow,, so-then how would the HT.secondary's electrical-circuit current-demand still become satisfied IF the battery were to happen-to go off-line (due-to a busted wire-terminal), whilst the lights & horn (and stereo & air-conditioner, etc) all happen to be turned-off ?

We .are talking about a DC system, aren’t we?

____ Yes, (of-course) ! ...
I do realize that it can possibly be left to be somewhat confusable when both ign.system-types are mentioned within the same post,, but I'm most-always reasonably fairly careful to make each separately clear, whenever both happen to be covered within the same paragraph, (and any paragraph-itself [with it's very-own punctuation*] is supposed-to tip-off the reader that it's main-subject/topic has significantly changed, from that of the previous-paragraph).
__ (* It's a shame that net.forums such as this, ignore paragraph-punctuation these-days,, so I have-to resort to other-means -[with these space-holding lines: ____ & __ ], in order to signify main & minor paragraph-punctuation.)



" Well I don’t know how there will be any secondary current, if the battery is out of the circuit? "

____ Well Harvey, apparently you've been OVERlooking a rather important closely-related circuit, which doesn't really appear to-be an actual circuit, (but in effect, it really IS) ! _ And for now, that's as much of a clue as I'm going to provide,, as I wish for someone-else (other than myself) to bring to light that which I've been jesting-of.
__ I'm sure that at-least Jim knows, but others such as he may-not be realizing that they actually already indeed know.



" The secondary current will flow through the lowest resistance path, "

____ Yes of-course, indeed so ! - (Through the lowest-resistance circuit-pathway & TO the GREATEST reverse-polarity circuit-connection !)
__ So-then why would it choose to go-through the battery to merely get-to just the main-section of the secondary-coil,, when instead, it could more-directly choose to go-to the connection-end of the ENTIRE-length of the acting-secondary (of the complete auto-transformer winding) ?

Secondly, what-IF the spark-plug's gap happened to become reduced to near negative-clearance, what then would be the resulting-effect of the HT.secondary's HT.current on the battery, etc., (would we then be able to see a HT.spark jumping somewhere inside the battery, or what ?) ?

I think you missed this bit.
“As for the “HT.sparking-juice”, that High voltage of about 12kv from the secondary, only exists across the resistance of the plug gap. The rest of the circuit only flows battery voltage at about 2amps.”.

____ No, I didn't miss that, (in fact that's ONE-thing I was referring-to [at the bottom of my earlier-post] when I stated: (cuz I'm led to think-of more than one concept that your chosen-wording may be meaning to convey)),, and had actually read it more than once, but just wasn't sure of exactly how it was meant to be understood (cuz it seems partially incorrect).



" If the plug gap is zero, there will be no Hi voltage. It is the resistance of the plug gap that causes the voltage to rise, to overcome the resistance. No resistance in the circuit, no ‘HT spark’ to jump anywhere. "

____ Right, cuz if the circuit-resistance is zer0, then the voltage-drop will also be zer0 !
__ It seems that you're fairly pretty-smart about this-stuff, Harvey !
So where have you always been whenever electrical-stuff has been discussed in the past ?


" If the plug gap is zero, there will be no Hi voltage. "

____ Of-course that's quite true, as there will then be no high-VOLTAGE,, however the HT.current (of the HT.secondary) will still remain under high-TENSION ! _ ('Tension' is electrical-drive/pressure, [before it ever becomes measurable as 'voltage'].) ...
__ Some believe that 'voltage' is the intended term for representing "electrical-drive/pressure", but actually, electrical-PRESSURE is what 'tension' really is. _ And 'tension' is-to 'voltage', in much the same relationship* as 'temperature' is-to 'Fahrenheit' (or Celsius), (* as an example that comes-to-mind).

____ Well if indeed there's "no difference between the two types" , then exactly-WHY would there be TWO-types of HT.coils -(the Green & the Red labeled versions) ?

" Looking at the first diagram of a battery powered coil, that you posted. If the battery is removed and replaced with alternator power, with the blue wire feeding the coil, it is the same as the Ducati Magneto system. "

" As I see in your reply to Ducatikid, It is an Energy Transfer system, and not an Inductive system. This makes a difference in the primary windings of the two. In the inductive system the primary is fed 12V, and the secondary is produced on the collapse of the field. In the Energy system that primary is fed about 250V, and the secondary is produced on the rise of the field. "

____ All quite true, however the primary-voltage in the 160-system is not so much as "250V" ! _ Rather, it's only up-to as much as 70-volts (BEFORE being subjected to the operating-circuit, when it's then bled-down to much less).



" So the primary windings may well be different. "

____ Yes, no-doubt so... I suspect that the Green-coil primary-winding is more-like that of the main-secondary winding, in-that there are more coil-turns of a finer gauge,, (as compared to the likely heavier gauge of the primary-winding that's meant to-be charged by battery-type power-juice).


Enlightening-Cheers,
-Bob