The Old Standard Ignition System. Battery. Coil. Points. And Condenser....

[Magluvin]

I want to make 2 point.
I. if the spark occurs when the points close then wouldn't it mess up the timing and cause preignition?
I think a weak spark might occur but like trying to start a small engine with a rope - pull it slowly
and it will never start cause the spark is too weak to make it fire.

2.The Tesla circuit is so clever but thinking ahead is there something that we could do with the plasma
that would give us something else that is desireable.

Bruce Perreault once told us to collect some power from a spark gap without a wire connection and we did.
A coil near that plasma will collect power in a collection capacitor.....Each time it sparks it will add more to the
capacitor if it has a diode to keep it there.

But we got stuck there and did not know where to go with that.
So I post that for some creative ideas.

Norman

What we would have to do is check the distributor for position of the rotor to see if the 'close contact' spark is even anywhere near the next electrode post for the next cylinder to misfire. Need to look at that.  Is it just at the end of the combustion stroke that the switch finally closes?  Is the distributor rotor far enough away from  the the previous distributor post it just fired into at the correct time, or is the rotor already far away and close to the next post to close contacts fire too early into the next plug in the firing order?

Im thinking it closes before the end of the combustion stroke or even lights fire to some too rich mixture that all the fuel hasnt burned yet and lights it up when the exhaust valve is open and pop pop..   I cant say that the closed spark happens to fire the next plug inline when the next cyl has its intake valve open to send fire thogh the carby, as brad seems to indicate.  You can blow flames out the carb all day if you turn the distributor 180.

"2.The Tesla circuit is so clever but thinking ahead is there something that we could do with the plasma
that would give us something else that is desireable."

I cant say..   Like what good could it do? Any ideas?  I think Tesla liked sparks that just jumped then somehow, whether with magnets or air pressure at the gap, kill it off before it burns itself out..  From most all I have read that was key somehow..

Mags

[Magluvin]

Mh says in Pm that he has hit the mother load on this. Says the primary and cap oscillate during the plasma burn...not after like he has been saying just yesterday.

Well I have a little insight on that. Ill tell it after his new explanation.  At least he is now seeming to accept the primary and cap oscillations. But lets see what he comes up with.  just told me in PM.


Mags

[tinman]

Hey Brad

Dont know if you have seen last nights vid.  It shows the switch on spark you say there is. The only really difference in the circuit is the addition of the ballast resistor and the relay as contacts instead of the knife switches of my first vids.  There was never a closed switch spark then.  But here I only get it when the cap is connected, not when the cap us removed. Am I doing something wrong here? TK keeps talking about dwell in pm. Might that be the case here? I can adjust the timing of the relay to fit given specs at say and idle rpm time frame to try.  Like during a 60deg rotation they could be set up at 32deg closed and 28deg open...If you think that may help figure out this particular issue, but I do not think thats it thus far.

I sorry for the other day..  With all that i have to deal with from MH, it all seemed like you were coming to counter my views also, and it just lit me up. lol  From the mysterious approvals of Mhs posts that I nor Grum had done, and I could only imagine it was you, then you posting your post that caboggled me as I really didnt think the closed contact spark could occur.  I have other vids using this same coil that i have used off and on for years now, and never seen it.  So It did seem like it was made up.. I even tried it before I took apart the knife switch circuit and could not get it to happen..  I cant say yet that the ballast resistor is the key yet. Going to remove that today to see.   

And with the cap in the circuit across the switch(is the only time I can produce the spark switch closed) I cannot see how it would help like you explain to prevent the closed spark.  Can you help me out with understanding what you mean there? 

Im not interested in how it has to do with the resonance part, I just want to know for me because Im getting the spark with the cap and not without the cap as you seem to explain it would happen.. So again, maybe there is something wrong with how Im doing it and if you could help figure it out that would be cool.

Mags

Hi Mag's

I have been quite ill the last couple of day's,and have not left my bed much.

It is good to see that you have seen the spark during switch close.

In the points ignition system,in this case,the condenser never allows the voltage across the primary coil to fall to 0,and so the amplitude of change within the primary is smaller with the condenser in place than without it.
This stops the switch closed spark taking place.

I sorry for the other day..

All good Mag's.

I will shoot that video as soon as im back on my feet--maybe even today.

TK keeps talking about dwell in pm

Dwell time is just how long the coil is energized--or points closed in this case.
This is adjusted by the points gap. Larger the gap,the less the dwell time.


Brad

[MileHigh]

Okay, I finally found a 100% credible source that goes over the voltages observed on the primary and secondary during an ignition cycle.  There is resonance between the primary and the capacitor during the plasma burn, but it is a qualified resonance which I will explain below.

The source is Crypton Diagnostic Equipment in South Africa, they are automotive techs.

http://www.crypton.co.za/

An explanation of the ignition cycle with clickable waveforms:

http://www.crypton.co.za/Tto%20know/Ignition/ignition%20overview.html

Small discussion on spark burn time duration for street cred:

http://www.crypton.co.za/Tto%20know/Ignition/burn%20time.html

The primary waveform:

http://www.crypton.co.za/Tto%20know/Ignition/primary.jpg

The secondary waveform:

http://www.crypton.co.za/Tto%20know/Ignition/secondary.jpg

Discussion about the waveforms:

Starting with the secondary, you see the initial high-voltage peak that ignites the plasma.  That's actually the secondary version of the primary voltage increasing as it charges the capacitor.  Then you have the straight and steady spark burn voltage line.  This is where the secondary completely drains the core of magnetic energy.  There is no current waveform, but if you could see one, it would look roughly like a linear down-ramp to zero.

Then you see ringing on the secondary, the so-called "resonance."  This is nothing more than a reflection of the ringing on the primary, so I will discuss it in the primary discussion.  There is no plasma generation during this ringing.

Now moving on to the primary.  You see the voltage go up on the primary until the secondary punches through the air and creates the plasma.  Then you see a high-frequency ringing.  The high-frequency ringing is ringing between the primary and the capacitor during the burn time of the secondary.  Since the secondary is doing a DC-type of burn, and the primary-secondary form a transformer, the plasma looks like a load to the ringing primary.  That's why the exponential decay is very fast during the duration of the plasma burn.  So how would this affect the current waveform of the plasma burn?  The answer is simple, we know the current waveform for the plasma burn is roughly a linear down-ramp to zero, and therefore there would be a slight "wiggle" superimposed on the current waveform because of the coupling to the resonating primary.

After the burn is completed, you notice that the frequency of the resonating drastically changes and gets much lower, and the decay envelope to the resonance is much slower.  Note during the burn the inductance is reduced, and is based on the primary which has less turns than the secondary.  Once the secondary has finished its burn, it stops acting like a transformer and the secondary "joins forces" with the primary to create a larger inductor. So the effective inductance increases and therefore the resonant frequency decreases.  Likewise, after the burn is over, the burning plasma resistor is not a load on the primary any more, and therefore the resonance oscillation decays away more slowly.

So what is the skinny on this?   It is as follows:  The primary and capacitor resonate during the plasma burn and after the plasma burn.  But this oscillation has no real affect on the main function of the circuit which is the secondary doing a big energy dump to create the spark on the secondary.  The fact that the primary is resonating with the capacitor the whole time has no real affect on the plasma burn.

So from my previous comments where was I wrong:  The answer is that I thought that once the plasma ignited and the energy was draining away from the core and this put a pretty constant DC bias on the primary.  So if there was any ringing it would be relatively low in amplitude.  It's apparent from the primary waveform that once the burn starts that gives the primary-capacitor LC resonator enough of a jolt to have it resonate with some robustness.  However, as stated before, this resonance only imposes a small "wiggle" on the decaying current waveform of the main burn of the secondary.  The secondary is an inductor discharging into a non-linear plasma resistor and it is a current source with a one-track mind - keep the current as constant as possible and as the energy level in the core drops, the current level also drops.

So what are the implications for Magluvin's claim of a "gain because of the magic of resonance."  Well, if the primary and the capacitor are resonating and pumping power into the spark plasma, then clearly the amount of energy put into the plasma during the burn increases.  But of course Magluvin is learning this as he reads this himself so it's difficult to do another "victory dance."  If you are going to be realistic you say, "Okay, the ringing primary-capacitor puts perhaps a small bit of extra energy into the plasma, but it is not truly a "resonance phenomenon giving the circuit a gain."  I am pretty convinced that the real "gains" come from the capacitor preventing the points from arcing.

All of the above discussion is actually material that Magluvin should have been generating himself.  He has the test setup but he refused to do anything, presumably because he can't.  For example, how much energy is in the core of the ignition coil?  We know the voltage on the capacitor so getting the energy in the cap is trivial.  You can measure the energy in the core with a trivial test without even touching the secondary.  How does the cap energy compare to the magnetic energy in the core?  If you put a low value resistor on the secondary to clamp the secondary voltage to a low value (simulating the plasma) can you make safe measurements of the energy output from the coil and then make some estimates of what the what gains you get from the primary-capacitor resonator?  I am pretty sure you can.  These are all interesting and challenging questions that Magluvin could have been investigating but instead he just walked away.

[Magluvin]

Ill go over it in a couple hours.  Doing laundry

Remember when I first brought up the subject of the ign system with you MH?   I said lastly in that post....

"Or could it be that if there is a time period of ringing during the spark, that the succession of sparks ionizes the air starting with the first pip and the successive sparks can cross that path with more current till its finished?"


So maybe you got locked onto the plasma by my saying that above.  But here is something I have found very strange. Said so here in a post before I was doint my first vid.  the cam stopped for some reason at 13min and wasnt finished. Didnt have time to fit it in in the first vid because I was worried the cam would fail if I went to long.. But here is an oddity


The secondary hv terminal goes to the distributor and then the spark plug and to battery ground..  Whats crazy is, if the spark happens when the points are open, then where is the path for the other end of the secondary???  The bottom end of the sec coil is only connected to gnd via either the condenser as a path, or the spark between the points gap OR through the ballast resistor and through the pos of the battery to gnd..


Which is it?   I connected my gnd end of my spark plug to battery gnd. Then to - of the coil, then to + of the coil.  Didnt make any difference in the spark that I could see.

But, cap or no cap, things were the same.  Even the points gap spark were the same.  Could the HV sec have a path to gnd through the cap? Or the points spark?  Strange


But in each case the resonant ring on the scope was there with the cap, and not there without it..
So its just an odd mystery thus far, that does not change the circumstances of spark with cap or spark with no cap....More later 

Im leaning toward the HV path is from the pos terminal of the coil and through the ballast and battery being I see no difference in operation where ever I put the spark plugs gnd connection

Seen some internal coil connection pics where some the bottom end of the sec is connector to the + of the primary and some that are to the - of the primary.  the whole thing once i realized the - terminal of the coil I was using as a plug gnd path was not battery gnd like the battery and engine block are always basically gnd and if the contacts are open where is the plugs gnd terminal back to the coil.. 

Its probably not just me that just assumed that the bottom end of the sec was just always direct battery gnd.. 

mags