Resistor plugs & resistor wires?

[user-23911]

It takes a set amount of energy to break the electron free from the nucleus.
More molecules between the electrodes means more energy required.

[Kevin Johnson]

... It does seem counter intuitive that closer molecules would offer more resistance.

https://web.archive.org/web/20170203092 ... te1425.pdf

See Table 1 in 2.1.1

BTW, you might want to snag this at no cost prior to it being discovered and being deleted. It was archived exactly one time.

[nitro2]

Back in the day, Champion made a plug tester that has a pressurized chamber for testing plugs. It has a model T coil inside and connects to an air compressor. I have one and it works great. I set the pressure at around 55 lbs to test T plugs. The difference in spark is eye opening.
Champion 1.gifChampion 2.gif

You can still get spark plug testers, I've used them in the past as well. It does seem counter intuitive that closer molecules would offer more resistance.

Low pressure spark plug testers are commercially available, but proper testers use higher pressures and a modern relevant ignition system, ideally a high powered racing engine ignition system.

Air is not a resistor, nor a conductor.

[Circlotron]

It takes a set amount of energy to break the electron free from the nucleus.
More molecules between the electrodes means more energy required.

How about with metals? They are closer yet.
Now it would be interesting to know how it affects chemical reactions, combustion.

The number of electrons in the outer shell of the atom makes all the difference.
Three or less means it is a conductor. Less is better.
Five up to eight is an insulator. More is is better.

With an insulator you have to apply *way* more effort to get those outer shell electrons moving from one atom to the next. Copper has only one outer shell electron so is easy peasy.

[user-23911]

How about with metals? They are closer yet.
Now it would be interesting to know how it affects chemical reactions, combustion.

You learn that at school, or at least we did way back as 11 year olds. But probably not these days.

[Firedome8]

How about with metals? They are closer yet.
Now it would be interesting to know how it affects chemical reactions, combustion.

You learn that at school, or at least we did way back as 11 year olds. But probably not these days.

So what is that comment for? I'm 11 almost times 6 and know well about valence electrons. Just trying to make an interesting discussion.
When I was a kid climbing towers I didn't have enough sense not to I could feel the affects of the electrical discharge on a 90 degree dry summer day on my arms/ hair etc. There was no arcing to me if there would have been I'd not be here now. Just saying.......


And from Kevins info.

As mentioned earlier [6, 14], nitrogen is an ideal gas
to use: it is abundant, cheap, inert, non-toxic, nonflammable,
and unquestionably environmentally
acceptable.
However, nitrogen is a non-electronegative gas (it
does not attach electrons) and for this reason its dielectric
strength is rather low. Nitrogen, however, is a strong
electron-slowing down gas and this property accounts for
its relatively good dielectric properties in non-uniform
fields and in the presence of conducting particles, and for
its excellent performance in mixtures with electronegative

And for airs resistance found this.
Its resistivity is approx. 2x10^16 ohm-meter

The term dielectric strength May be more fitting description approx 20kv/cm.

[Fred Winterburn]

There is always a significant voltage overshoot prior to the spark occurring beyond the actual voltage requirement for the spark itself. Because some energy is required to ionize the gap prior to breakdown (in the form of a corona discharge), there is some current flow prior to the actual spark. Adding more secondary side resistance results in a measurable increase in the voltage overshoot. It's only a few percent, but not negligible. So yes, adding secondary side resistance does increase the voltage required for spark breakdown. Of course, increased secondary side resistance also leads to lower total spark energy and duration. I've added an article I wrote that doesn't discuss secondary side resistance in particular but does discuss voltage overshoot. Fred

Ignition Voltage Overshoot.pdf

Also, the resistance of the leads is in series with the resistor [ if used ] in the spark plug & this combined resistance, which is also in series with the air gap, is only a fraction of the resistance across the air gap of the plug electrodes. So the resistance of the plug lead + plug resistor has negligible effect on the required voltage to ionise the gap in preparation for spark current to flow. Once current flows across the gap & voltage drops to ~1000-1100v, THEN the circuit resistance has a significant impact [ reduces current ].

[user-23911]

And for airs resistance found this.
Its resistivity is approx. 2x10^16 ohm-meter

Air doesn't have resistance nor resistivity as such.

Resistance implies a fixed relationship between voltage and current and gasses don't behave like that.



Paschen's law states that V = PD.
The breakdown voltage = pressure times distance.


Then after breakdown happens and current begins to flow, the gas exhibits a negative resistance.
More current = less voltage.

Exactly the same as an arc welder.

[Schurkey]

There is always a significant voltage overshoot prior to the spark occurring beyond the actual voltage requirement for the spark itself.

I learned something new today. Thanks.

[Tuner]

despite the fact the variation in voltage overshoot is easily measurable with the right equipment. You will not see this on an oscilloscope without comparison testing, which is why, I believe, this is not a better known phenomenon. Fred Winterburn

What is the procedure employed to accomplish this comparison testing ? Is 100 MHz fast enough or how fast a scope is required?

[user-23911]

You see it using an analogue scope on the primary side when set up correctly.
Usually a spike of 350 to 400 volts. Knowing the turns ratio you can calculate the secondary voltage by mutiplying by it.
You can't get accurate measurements on the secondary side.
You might think you can but you can't.

[user-23911]

There is always a significant voltage overshoot prior to the spark occurring beyond the actual voltage requirement for the spark itself.

That's due to the capacitance, resistance and inductance of the HT leads.

[lvecch]

Hello, I understand there have to be a resistance in the path from the spark Coil, distributor, wire and spark plug in order to reduce the amps and the electromagnetic emission. But I have made some tests and I observed that is not only the amount of resistance what is needed, but it has to be distributed along the path. For example, I observed if I put a 15Kohms spark plug wire cobined with a 3.5ohms spark plug, it works well, but if I put a 20Kohms wire and a non resitor spark plug, it affect the engine controller. I do not understad why. Is seems that it can´t be a piece of conductor longer than x without a resistor, otherwise it increase the emission. I am an electronic engineer and the only idea that could come to my mind is some kind of stationary waves produced on the non resistive conductor longer that some amount. Could somebody guess about it?

[Schurkey]

Hello, I understand there have to be a resistance in the path from the spark Coil, distributor, wire and spark plug in order to reduce the amps and the electromagnetic emission.

Reducing current flow does not require resistance.

For example, helical-wound plug wires offer very low resistance (big marketing advantage) but they still limit current flow by having high inductance. Nobody knows about--or questions--inductance, so they think that "low resistance" helical plug wires means more energy is going to the spark plug.

But I have made some tests and I observed that is not only the amount of resistance what is needed, but it has to be distributed along the path. For example, I observed if I put a 15Kohms spark plug wire cobined with a 3.5ohms spark plug, it works well, but if I put a 20Kohms wire and a non resitor spark plug, it affect the engine controller. I do not understad why. Is seems that it can´t be a piece of conductor longer than x without a resistor, otherwise it increase the emission. I am an electronic engineer and the only idea that could come to my mind is some kind of stationary waves produced on the non resistive conductor longer that some amount. Could somebody guess about it?

No idea.

Both my motorcycles use old-fashioned solid-core plug wires with a 5K "pellet" resistor in the spark plug boot. No noticeable RFI.

CB1100F_Spark_Cap_XD05F_01.jpg

[rebelyell]

Gosh, wish late great Nelson Crozier had stepped in before ...
May God Always Bless and Keep Arthur +

https://www.legacy.com/us/obituaries/ch ... id=9508505