![]() The wide use of spark-gap transmitters led to the nickname "sparks" for a ship's radio officer.Įlectric sparks are used in different kinds of metalworking. They were later supplanted by vacuum tube systems and by 1940 were no longer used for communication. Spark gap transmitters were widely used in the first three decades of radio from 1887–1916. This information is used to stop an ignition device from sparking after the flame is lit or restart the flame if it goes out.Ī spark-gap transmitter uses an electric spark gap to generate radio frequency electromagnetic radiation that can be used as transmitters for wireless communication. Auto reignition is a safety feature that is used in some flame igniters that senses the electrical conductivity of the flame and uses this information to determine whether a burner flame is lit. The voltage for the spark is provided by an ignition coil or magneto that is connected to the spark plug with an insulated wire.įlame igniters use electric sparks to initiate combustion in some furnaces and gas stoves in place of a pilot flame. The electric discharge in a spark plug occurs between an insulated central electrode and a grounded terminal on the base of the plug. 1900)." Ignition sources Įlectric sparks are used in spark plugs in gasoline internal combustion engines to ignite fuel and air mixtures. Spark transmitter used for ship to shore communication up to 10 km ( c. Lightning is an example of an electric spark in nature, while electric sparks, large or small, occur in or near many man-made objects, both by design and sometimes by accident. An electric spark can also occur within insulating liquids or solids, but with different breakdown mechanisms from sparks in gases. If the power supply continues to supply current, the spark will evolve into a continuous discharge called an electric arc. Once the gap breaks down, current flow is limited by the available charge (for an electrostatic discharge) or by the impedance of the external power supply. The exponentially-increasing electrons and ions rapidly cause regions of the air in the gap to become electrically conductive in a process called dielectric breakdown. At some point, thermal energy will provide a much greater source of ions. As they collide with air molecules, they create additional ions and newly freed electrons which are also accelerated. At the beginning stages, free electrons in the gap (from cosmic rays or background radiation) are accelerated by the electrical field. Experimentally, this figure tends to differ depending upon humidity, atmospheric pressure, shape of electrodes (needle and ground-plane, hemispherical etc.) and the corresponding spacing between them and even the type of waveform, whether sinusoidal or cosine-rectangular. ![]() For air, the breakdown strength is about 30 kV/cm at sea level. A spark is created when the applied electric field exceeds the dielectric breakdown strength of the intervening medium. The rapid transition from a non-conducting to a conductive state produces a brief emission of light and a sharp crack or snapping sound. Michael Faraday described this phenomenon as "the beautiful flash of light attending the discharge of common electricity". Lightning is a natural example of an electric spark.Īn electric spark is an abrupt electrical discharge that occurs when a sufficiently high electric field creates an ionized, electrically conductive channel through a normally-insulating medium, often air or other gases or gas mixtures.
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