Elektrilahendused

Elektrilahendused refer to the passage of electric current through a medium that is normally an electrical insulator. This occurs when the electric field strength in the insulator exceeds a critical value, known as the dielectric strength, causing it to break down and become conductive. Various phenomena fall under the umbrella of electrical discharges, depending on the conditions and the medium.

Common examples include lightning, which is a natural electrical discharge between clouds or between a cloud and the ground. Another familiar example is the spark that can be observed when a static electric charge is discharged, such as when touching a metal doorknob after walking across a carpet. In many electronic devices, controlled electrical discharges are utilized. For instance, fluorescent lamps and neon signs work by passing an electrical current through a gas, causing it to emit light. Arc welding uses a high-temperature electrical arc to melt and join metals.

Electrical discharges can also be a cause of failure in electrical equipment. Insulation breakdown in power lines or electronic components can lead to short circuits and damage. The study of electrical discharges is important for understanding phenomena in atmospheric physics, electrical engineering, and materials science. Factors influencing electrical discharges include the type of insulating material, its thickness, temperature, pressure, and the waveform and magnitude of the applied voltage.