
An electric match is a device that uses an externally applied
electric current
An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge c ...
to ignite a
combustible
A combustible material is a material that can burn (i.e., sustain a flame) in air under certain conditions. A material is flammable if it ignites easily at ambient temperatures. In other words, a combustible material ignites with some effort a ...
compound.
Electric matches use a
bridgewire consisting of a
heating element
A heating element is a device used for conversion of electric energy into heat, consisting of a heating resistor and accessories. Heat is generated by the passage of electric current through a resistor through a process known as Joule heating. He ...
to ignite a pyrogen, which is a quantity of readily ignited
pyrotechnic initiator composition.
Electric matches can be used in any application where source of heat is needed at a precisely controlled point in time, typically to ignite a propellant or explosive. Examples include
airbag
An airbag is a vehicle occupant-restraint system using a bag designed to inflate in milliseconds during a collision and then deflate afterwards. It consists of an airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. ...
s,
pyrotechnics
Pyrotechnics is the science and craft of creating fireworks, but also includes safety matches, oxygen candles, Pyrotechnic fastener, explosive bolts (and other fasteners), parts of automotive airbags, as well as gas-pressure blasting in mining, q ...
, and military or commercial
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ex ...
s.
Design
Electric matches consist of two parts, a
bridgewire and a
pyrogen. The bridgewire is a
heating element
A heating element is a device used for conversion of electric energy into heat, consisting of a heating resistor and accessories. Heat is generated by the passage of electric current through a resistor through a process known as Joule heating. He ...
, typically in the form of a loop or coil of thin wire, which is encased in the pyrogen, which is a quantity of readily ignited
pyrotechnic initiator composition. If the pyrogen is sufficiently conductive, it can act as the bridgewire as well. Electric matches also come with provisions for attaching an electric current source, and they may be provided with a protective cover and/or a means to attach them to the device to be ignited.
To operate an electric match, a source of electricity of appropriate voltage and current is needed to provide current to the match. When sufficient
electric current
An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge c ...
is passed through the bridgewire, the
resistive heating
Joule heating (also known as resistive heating, resistance heating, or Ohmic heating) is the process by which the passage of an electric current through a conductor produces heat.
Joule's first law (also just Joule's law), also known in countr ...
causes the element to rise above the ignition temperature of the pyrogen, and the pyrogen begins to burn.
Commercial electric match manufacturers often specify 3 key parameters of an electric match: the resistance (often around 2
Ω), a recommended firing current (often around 1
A), and a maximum no-fire current. The "test" button on a firing system typically tests the system by sending a current limited to well below the no-fire current (often 200mA), to allow for detection of common problems such as short circuits and disconnected open circuits.
Applications
Typical applications include:
*
Airbag
An airbag is a vehicle occupant-restraint system using a bag designed to inflate in milliseconds during a collision and then deflate afterwards. It consists of an airbag cushion, a flexible fabric bag, an inflation module, and an impact sensor. ...
deployment
*
Pyrotechnics
Pyrotechnics is the science and craft of creating fireworks, but also includes safety matches, oxygen candles, Pyrotechnic fastener, explosive bolts (and other fasteners), parts of automotive airbags, as well as gas-pressure blasting in mining, q ...
* Military or commercial
explosive
An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ex ...
s
*
Model rocket
A model rocket is a small rocket designed to reach low altitudes (e.g., for a model) and #Model rocket recovery methods, be recovered by a variety of means.
According to the United States National Association of Rocketry, National Associati ...
ry
*
Fireplace
A fireplace or hearth is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room. Modern fireplaces vary in heat efficiency, depending on the design.
...
s:
natural gas
Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium ...
,
propane
Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum ref ...
*
Gas stove
A gas stove is a Kitchen stove, stove that is fuelled by flammable gas such as natural gas, propane, butane, liquefied petroleum gas or syngas. Before the advent of gas, cooking stoves relied on solid fuels, such as coal or wood. The first gas sto ...
s and
barbecue
Barbecue or barbeque (often shortened to BBQ worldwide; barbie or barby in Australia and New Zealand) is a term used with significant regional and national variations to describe various cooking methods that employ live fire and smoke to coo ...
s
Electric matches, or electronic ignitions, are used in
natural gas
Natural gas (also fossil gas, methane gas, and gas) is a naturally occurring compound of gaseous hydrocarbons, primarily methane (95%), small amounts of higher alkanes, and traces of carbon dioxide and nitrogen, hydrogen sulfide and helium ...
and
propane
Propane () is a three-carbon chain alkane with the molecular formula . It is a gas at standard temperature and pressure, but becomes liquid when compressed for transportation and storage. A by-product of natural gas processing and petroleum ref ...
fueled commercial and
household appliance
A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine which assists in household functions such as cooking, cleaning and food preservation.
The domestic application attached to ...
s and amenities. Some examples are
gas stoves and
barbecue
Barbecue or barbeque (often shortened to BBQ worldwide; barbie or barby in Australia and New Zealand) is a term used with significant regional and national variations to describe various cooking methods that employ live fire and smoke to coo ...
s, interior and
swimming pool
A swimming pool, swimming bath, wading pool, paddling pool, or simply pool, is a structure designed to hold water to enable Human swimming, swimming and associated activities. Pools can be built into the ground (in-ground pools) or built abo ...
hot water heaters and
boiler
A boiler is a closed vessel in which fluid (generally water) is heated. The fluid does not necessarily boil. The heated or vaporized fluid exits the boiler for use in various processes or heating applications, including water heating, centra ...
s,
fireplace
A fireplace or hearth is a structure made of brick, stone or metal designed to contain a fire. Fireplaces are used for the relaxing ambiance they create and for heating a room. Modern fireplaces vary in heat efficiency, depending on the design.
...
s and garden
fire pits, and
clothes dryer
A clothes dryer (tumble dryer, drying machine, drying device, or simply dryer) is a powered Home appliance, household appliance that is used to remove moisture from a load of clothing, bedding and other textiles, usually after they are washed in ...
s and
central heating system
A central heating system provides warmth to a number of spaces within a building from one main source of heat.
A central heating system has a Furnace (central heating), furnace that converts fuel or electricity to heat through processes. The he ...
s.
Electric matches may be subject to regulations, as they can be used to ignite explosives. For amateur pyrotechnic use, electric matches can be built from scratch or from a kit. Kits include the thin wire needed for the bridgewire, such as
nichrome
Nichrome (also known as NiCr, nickel-chromium or chromium-nickel) is a family of alloys of nickel and chromium (and occasionally iron) commonly used as resistance wire, heating elements in devices like toasters, electrical kettles and space he ...
wire, along with components for mixing the pyrogen. Scratch-built matches use thin wire which may be purchased or salvaged from sources such as
light bulb
Electric light is an artificial light source powered by electricity.
Electric Light may also refer to:
* Light fixture, a decorative enclosure for an electric light source
* ''Electric Light'' (album), a 2018 album by James Bay
* Electric Light ( ...
filaments, and
copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orang ...
wiring.
In addition to the readily-ignitable component of the electric match pyrogen, some matches may also add additional components to provide a hotter, longer-lasting flame for use on items that are difficult to ignite. For example, igniters for solid fuel
model rocket
A model rocket is a small rocket designed to reach low altitudes (e.g., for a model) and #Model rocket recovery methods, be recovered by a variety of means.
According to the United States National Association of Rocketry, National Associati ...
motors often include powdered metals, which provide more heat and duration to the match flame, for a more reliable ignition of the motor.
See also
*
Tubes and primers for ammunition
*
Primers
*
Blasting cap
A detonator is a device used to make an explosive or explosive device explode. Detonators come in a variety of types, depending on how they are initiated (chemically, mechanically, or electrically) and details of their inner working, which of ...
*
Micro combined heat and power
Micro combined heat and power, micro-CHP, μCHP or mCHP is an extension of the idea of cogeneration to the single/multi family home or small office building in the range of up to 50 kW. Usual technologies for the production of heat and power in ...
*
Renewable natural gas
*
Squib (explosive)
A squib is a miniature explosive device used in a wide range of industries, from special effects to military applications. It resembles a tiny stick of dynamite, both in appearance and construction, but has considerably less explosive power. ...
*
Pyrotechnic fastener
A pyrotechnic fastener (also called an explosive bolt, or pyro, within context) is a fastener, usually a nut or bolt, that incorporates a pyrotechnic charge that can be initiated remotely. One or more explosive charges embedded within the bolt ar ...
*
Exploding-bridgewire detonator
References
{{Firelighting
Fire making
Pyrotechnic initiators