What Is The Working Principle Of Spark Plug?

Under the action of high voltage, the air between the central electrode and the side electrode of the spark plug will rapidly ionize, forming positively charged ions and negatively charged free electrons. When the voltage between the electrodes reaches a certain value, the number of ions and electrons in the gas will increase like an avalanche, thus making the air lose its insulation, and the gap will form a discharge channel, causing "breakdown" phenomenon. At this time, the gas forms a luminous body, namely "spark". With its thermal expansion, there is also a "snap" sound. The temperature of this electric spark can be as high as 2000~3000 ℃, which is enough to ignite the mixture in the cylinder combustion chamber.