There is a very good wikipedia page on Paschens Law.
On Wed, 12 Jul 2023 at 15:52, John Woodgate <
jmw@...> wrote:
OK so far, I think. Have you
done a web search for 'Paschen's Law'?
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Best wishes
John Woodgate OOO-Own Opinions Only
Rayleigh, Essex UK
I hear, and I forget.
I see, and I remember.
I do, and I understand.
Xunzi (340 - 245 BC)
On 2023-07-12 15:45, Richard Andrews
via wrote:
Trying to grasp the resistance in a spark gap I had to write what
I know.
If anyone can refute my ideas, let me know.
The voltage and current relationship when a spark gap's gap is
increased is as follows:
??? Voltage: The voltage required to initiate a spark across the
gap increases
??? as the gap widens. This is because the air in the gap has to
be ionized
??? before a spark can occur, and it takes more voltage to ionize
the air as
??? the gap widens.
??? Current: The current that flows through the spark gap after it
has initiated
??? is relatively constant, regardless of the gap width. This is
because the
??? resistance of the ionized air is very low, so a large current
can flow even
??? with a small voltage difference.
??? For example, spark gaps are used in spark-ignition engines to
ignite the
fuel-air mixture. The spark plug in a spark-ignition engine has a
gap of about
0.020 inches, and the voltage required to initiate a spark across
this gap is
about 20,000 volts. However, once the spark has initiated, the
current that
flows through the spark plug can be as high as 20 amperes.
??? The relationship between voltage and current in a spark gap is
not linear.
As the gap widens, the voltage required to initiate a spark
increases
exponentially. This means that a small increase in the gap width
can result in
a large increase in the voltage required to initiate a spark.
??? The voltage and current relationship in a spark gap is also
affected by the
type of gas that is present in the gap. Air is the most common gas
used in
spark gaps, but other gases such as argon and helium can also be
used.
The breakdown voltage of a gas is the voltage required to ionize
the gas,
and it is different for different gases. This means that the
voltage required
to initiate a spark in a spark gap will be different depending on
the type of
gas that is present in the gap.
