Spark Gaps In Series Voltage?

Thread Starter

russwr

Joined Aug 29, 2017
34
If positive only, high voltage SOURCE fires first accessory spark gap of 8mm as 24,000 volts, doesn't the second spark gap IN SERIES to the the first as "connected," smaller 2mm gap, fire at the same high voltage also to ground? 1mm/per 3000v spark in air is standard value. Seems as though volts has to go through the first as an EFFORT, just to get to the second one. This is important information needed on bench testing of electrical projects. (re edited)
 
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BobTPH

Joined Jun 5, 2013
8,657
If you put two spark gaps in series, I don’t see how either ever fires. The electrodes in the middle have no connection to the circuit so they cannot develop a potential.
 

crutschow

Joined Mar 14, 2008
34,002
The voltage will build up across the first gap, which will also cause voltage to built up across the second gap, due to an initial, small ionizing current through the gaps as it nears the breakdown voltage of the gaps.
They will then fire together when the voltage is equal to the gap breakdown voltage of both added together.

Obviously it's not possible for the gaps never to fire, just because they are in series.
 

BobTPH

Joined Jun 5, 2013
8,657
My intuition tells me that they must actually fire, but I find it hard to see the mechanism.

Think of two polarized capacitors back to back. They make a non-polarized capacitor because the lack of a current path into it out of the junction makes the reverse voltage linkage impossible. Why is that not the same here?
 

Lightium

Joined Jun 6, 2012
158
The voltage will build up across the first gap, which will also cause voltage to built up across the second gap, due to an initial, small ionizing current through the gaps as it nears the breakdown voltage of the gaps.
They will then fire together when the voltage is equal to the gap breakdown voltage of both added together.

Obviously it's not possible for the gaps never to fire, just because they are in series.
Right crutschow, both added together.
 

BobTPH

Joined Jun 5, 2013
8,657
We know the potentials on the two outer connections. But what is the potential on the conductor between the two gaps?
 

MisterBill2

Joined Jan 23, 2018
17,756
Current does flow prior to the breakdown that becomes an actual spark. And it happens quite rapidly. The welder spark gaps in post#3 are a good example. Multiple gaps in series make it more reliable.
A dramatic example is lightning dancing across the ground from one piece of equipment to the next, until it reaches one without rubber tires. Really scary to watch from nearby.
 

Thread Starter

russwr

Joined Aug 29, 2017
34
You guys make me "irked". If there is no correct answer to question that's known, then don't reply. I needed to know the voltage accross spark plug when there is an in series accessory spark gap with also a resistance included of .6 ohm. If plug is 2mm gapped, and 1st gap is 8mm, then what high voltage does spark plug fire at in air? 1mm = 3000volts. I just thought there might be some smarter people that happened to know off hand this data . Now I have to do the bench set up for my own determination.
 
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shortbus

Joined Sep 30, 2009
10,044
You guys make me "irked". If there is no correct answer to question that's known, then don't reply.
First off no one is forcing you to be a member here. The real answer to your question is, no the voltage won't multiply.

Your starting to irk me, too. How many times do you need to be told overunity isn't allowed here? Just because you seen an engine running on water on Youtube, its not real life. Why not ask your questions to the guy that posted the video? He won't answer because he doesn't want you to know it was a fake video.
 

MisterBill2

Joined Jan 23, 2018
17,756
Charge does flow prior to breakdown and arcing. That is the mechanism of how it works. The shape of the surfaces affects the charge distribution, the physics to quantify it with accurate numbers is tedious. And because not all of the ionized air leaves the area instantly, the process is not perfectly repeatable.
 

BobTPH

Joined Jun 5, 2013
8,657
Yeah, I figured there must be some leakage that finally cascades into the breakdown and sparks as the voltage rises.
 

LowQCab

Joined Nov 6, 2012
3,935
In an Internal Combustion Engine there are ( used to be ) legitimate reasons for
installing an additional fixed Spark-Gap in the High-Voltage-Wire between
the Ignition-Coil and the Engine's Distributor.

The concept behind this "fix" requires some basic knowledge concerning the
operation of "Old-School" Automotive-Ignition-Systems and their limitations,
and,
the propensity for common ( at the time ) unregulated Engine designs to "Carbon-foul Spark-Plugs".

Old-School Ignition-Systems were only as powerful as
was deemed "adequate" for a smooth-running Engine.
This meant that if the Spark-Plugs in the Engine were developing very many Carbon-Deposits
on the Ceramic-Insulator, they could eventually create a "Carbon-Track" to Ground,
this quite often would act as a "Resistor", which could, and usually did,
drain-off the High-Voltage-Charge stored in the Ignition-Coil, causing a failure to create a Spark,
this would, in turn, cause a "miss-fire" which, inevitably, causes more Carbon-Deposits to be formed.

In looking for a solution to this all too common aggravation,
somebody came up with the idea of adding an additional in-line Spark-Gap before the Spark-Plug.
This works by preventing the Carbon-Deposit-Short-Circuit from slowly draining the
built-up Charge in the Ignition-Coil, and by, causing the Power of the Coil to be dumped,
all at once, in to the deposited "Carbon-Track" on the Ceramic-Insulator,
instantly vaporizing the "Carbon-Track" and
removing the Short-Circuit to Ground.

This technique is only beneficial on an Engine that has
the Ignition-Coil directly connected to the Spark-Plug,
and with enough Coil-Power to produce enough Voltage to jump the additional added Gap.

For multiple cylinder Engines with an Ignition-Distributor and a single Ignition-Coil,
this trick will be of no benefit.
The Distributor-Cap already provides this additional Gap between the Coil and the Spark-Plug.

Unmodified Cars built after approximately ~1975 / ~1980 will not benefit from ANY
modifications to the factory installed Ignition-System.


Resistance in the Spark-Plug-Wires, and/or, built inside the Spark-Plugs themselves,
will reduce premature Spark-Gap-Erosion of the Plugs and
will reduce RFI-Interference from the whole Ignition-System.
It will also extend the duration of the Spark in the Cylinder,
increasing the chances of a complete and efficient burn of all of the Fuel/Air-Mixture.

If You are Hot-Rodding an older Engine,
Combustion-Chamber modifications are required before
having any concern about the Ignition-System.
.
.
.
 

LowQCab

Joined Nov 6, 2012
3,935
There's nothing wrong about trying to get Water-Molecules to more easily dissociate
by way of finding the Resonant-Frequency of the Molecules.

As to whether or not it will still take more Power to dissociate them
than the Power they will ultimately release remains to be seen.

There are multiple known methods for increasing the separation Angle between the 2 Hydrogen-Atoms.
I have ~5 or ~6 schemes that may, or may not, do anything along this line,
but I don't have the time or inclination to pursue any of them currently,
especially in view of the fact that even if one of them was viable,
it would be immediately squashed, and that the
present Internal-Combustion-Engines that we have to work with are
so grossly inefficient, ( roughly ~25% ).

Fine-Water-Droplets will violently decompose when sprayed into a Plasma-Stream of Ionized-Air,
but it takes some serious Electrical-Power for what You get out of it.
.
.
.
 
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