An electromagnetic coil is an electrical conductor such as a wire in the shape of a coil. Electromagnetic coils are used in electrical engineering, in applications where electric currents interact with magnetic fields, in devices such as electric motors, generators, inductors, electromagnets, transformers, and sensor coils. Either an electric current is passed through the wire of the coil to generate a magnetic field, or conversely, an external time-varying magnetic field through the interior of the coil generates an EMF (voltage) in the conductor.
An inductor, also called a coil, choke, or reactor, is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. An inductor typically consists of an insulated wire wound into a coil.
An ignition magneto, or high-tension magneto, is a magneto that provides current for the ignition system of a spark-ignition engine, such as a petrol engine. It produces pulses of high voltage for the spark plugs. The older term tension means voltage.
A relay is an electrically operated switch. It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals. The switch may have any number of contacts in multiple contact forms, such as make contacts, break contacts, or combinations thereof.
A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high-frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits.
An induction coil or "spark coil" is a type of electrical transformer used to produce high-voltage pulses from a low-voltage direct current (DC) supply. To create the flux changes necessary to induce voltage in the secondary coil, the direct current in the primary coil is repeatedly interrupted by a vibrating mechanical contact called an interrupter. Invented in 1836 by Nicholas Callan, with additional research by Charles Grafton Page and others, the induction coil was the first type of transformer. It was widely used in x-ray machines, spark-gap radio transmitters, arc lighting and quack medical electrotherapy devices from the 1880s to the 1920s. Today its only common use is as the ignition coils in internal combustion engines and in physics education to demonstrate induction.
A spark gap consists of an arrangement of two conducting electrodes separated by a gap usually filled with a gas such as air, designed to allow an electric spark to pass between the conductors. When the potential difference between the conductors exceeds the breakdown voltage of the gas within the gap, a spark forms, ionizing the gas and drastically reducing its electrical resistance. An electric current then flows until the path of ionized gas is broken or the current reduces below a minimum value called the "holding current". This usually happens when the voltage drops, but in some cases occurs when the heated gas rises, stretching out and then breaking the filament of ionized gas. Usually, the action of ionizing the gas is violent and disruptive, often leading to sound, light and heat.
An ignition system generates a spark or heats an electrode to a high temperature to ignite a fuel-air mixture in spark ignition internal combustion engines, oil-fired and gas-fired boilers, rocket engines, etc. The widest application for spark ignition internal combustion engines is in petrol (gasoline) road vehicles such as cars and motorcycles.
A contact breaker is a type of electrical switch, found in the ignition systems of spark-ignition internal combustion engines. The switch is automatically operated by a cam driven by the engine. The timing of operation of the switch is set so that a spark is produced at the right time to ignite the compressed air/fuel mixture in the cylinder of the engine. A mechanism may be provided to slightly adjust timing to allow for varying load on the engine. Since these contacts operate frequently, they are subject to wear, causing erratic ignition of the engine. More recent engines use electronic means to trigger the spark, which eliminated contact wear and allows computer control of ignition timing.
A distributor is an enclosed rotating switch used in spark-ignition internal combustion engines that have mechanically timed ignition. The distributor's main function is to route high voltage current from the ignition coil to the spark plugs in the correct firing order, and for the correct amount of time. Except in magneto systems and many modern computer controlled engines that use crank angle/position sensors, the distributor also houses a mechanical or inductive breaker switch to open and close the ignition coil's primary circuit.
High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, high voltage refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant special safety requirements and procedures.
An ignition coil is an induction coil in an automobile's ignition system that transforms the battery's voltage to the thousands of volts needed to create an electric spark in the spark plugs to ignite the fuel. Some coils have an internal resistor, while others rely on a resistor wire or an external resistor to limit the current flowing into the coil from the car's 12-volt supply. The wire that goes from the ignition coil to the distributor and the high voltage wires that go from the distributor to each of the spark plugs are called spark plug wires or high tension leads. Originally, every ignition coil system required mechanical contact breaker points and a capacitor (condenser). More recent electronic ignition systems use a power transistor to provide pulses to the ignition coil. A modern passenger automobile may use one ignition coil for each engine cylinder, eliminating fault-prone spark plug cables and a distributor to route the high voltage pulses.
Capacitor discharge ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in outboard motors, motorcycles, lawn mowers, chainsaws, small engines, turbine-powered aircraft, and some cars. It was originally developed to overcome the long charging times associated with high inductance coils used in inductive discharge ignition (IDI) systems, making the ignition system more suitable for high engine speeds. The capacitive-discharge ignition uses capacitor discharge current to the coil to fire the spark plugs.
A hit-and-miss engine or Hit 'N' Miss is a type of stationary internal combustion engine that is controlled by a governor to only fire at a set speed. They are usually 4-stroke but 2-stroke versions were made. It was conceived in the late 19th century and produced by various companies from the 1890s through approximately the 1940s. The name comes from the speed control on these engines: they fire ("hit") only when operating at or below a set speed, and cycle without firing ("miss") when they exceed their set speed. This is as compared to the "throttle governed" method of speed control. The sound made when the engine is running without a load is a distinctive "Snort POP whoosh whoosh whoosh whoosh snort POP" as the engine fires and then coasts until the speed decreases and it fires again to maintain its average speed. The snorting is caused by the atmospheric intake valve used on many of these engines.
A variety of types of electrical transformer are made for different purposes. Despite their design differences, the various types employ the same basic principle as discovered in 1831 by Michael Faraday, and share several key functional parts.
High tension leads or high tension cables or spark plug wires or spark plug cables, colloquially referred to as HT leads, are the wires that connect a distributor, ignition coil, or magneto to each of the spark plugs in some types of internal combustion engine. "High tension lead" or "cable" is also used for any electrical cable carrying a high voltage in any context. Tension in this instance is a synonym for voltage. High tension leads, like many engine components, wear out over time. Each lead contains only one wire, as the current does not return through the same lead, but through the earthed/grounded engine which is connected to the opposite battery terminal. High tension may also be referred to as HT.
Inductive discharge ignition systems were developed in the 19th century as a means to ignite the air–fuel mixture in the combustion chamber of internal combustion engines. The first versions were low tension coils, then low-tension and in turn high-tension magnetos, which were offered as a more effective alternative to the older-design hot-tube ignitors that had been utilized earlier on hot tube engines. With the advent of small stationary engines; and with the development of the automobile, engine-driven tractors, and engine-driven trucks; first the magneto and later the distributor-type systems were utilized as part of an efficient and reliable engine ignition system on commercially available motorized equipment. These systems were in widespread use on all cars and trucks through the 1960s. Manufacturers such as Ford, General Motors, Chrysler, Citroen, Mercedes, John Deere, International Harvester, and many others incorporated them into their products. The inductive discharge system is still extensively used today.
The Delco ignition system, also known as the Kettering ignition system, points and condenser ignition or breaker point ignition, is a type of inductive discharge ignition system invented by Charles F. Kettering. It was first sold commercially on the 1912 Cadillac and was manufactured by Delco. Over time, it was used extensively by all automobile and truck manufacturers on spark ignition, i.e., gasoline engines. Today it is still widely used in coil-on-plug, coil-near-plug and in coil packs in distributorless ignitions. An alternative system used in automobiles is capacitor discharge ignition, primarily found now as aftermarket upgrade systems. Electronic ignition was a common term for Kettering inductive ignition with the points replaced with an electronic switch such as a transistor.
A trembler coil, buzz coil or vibrator coil is a type of high-voltage ignition coil used in the ignition system of early automobiles, most notably the Benz Patent-Motorwagen and the Ford Model T. Its distinguishing feature is a vibrating magnetically-activated contact called a trembler or interrupter, which breaks the primary current, generating multiple sparks during each cylinder's power stroke. Trembler coils were first used on the 1886 Benz automobile, and were used on the Model T until 1927.
An alternator is a type of electric generator used in modern automobiles to charge the battery and to power the electrical system when its engine is running.
