Electrical generator

In electricity generation, an electrical generator is a device that converts kinetic energy to electrical energy, generally using electromagnetic induction. The reverse conversion of electrical energy into mechanical energy is done by a motor, and motors and generators have many similarities. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, or any other source of mechanical energy.

Wind turbine

A wind turbine is a machine that converts the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill. If the mechanical energy is then converted to electricity, the machine is called a wind generator, wind turbine, or wind energy converter (WEC).
This article discusses the energy-conversion machinery. See the broader article on wind power for more on turbine placement, economics, public concerns, and controversy: in particular, see the wind energy section of that article for an understanding of the temporal distribution of wind energy and how that affects wind-turbine design. See environmental concerns with electricity generation for discussion of environmental problems with wind-energy production.
For a machine that generates wind, see Fan (mechanical). For an unusual way to induce a voltage using an aerosol of ionised water, see vaneless ion wind generator.

Machine

The scientific definition of a machine (derived from the latin machina) is any device that transmits or modifies particles. In common usage, the meaning is restricted to devices having rigid moving parts that perform or assist in performing some work. Machines normally require some energy source ("input") and always accomplish some sort of work ("output"). Devices with no rigid moving parts are commonly considered tools, or simply devices, not machines.
People have used mechanisms to amplify their abilities since before written records were available. Generally these devices decrease the amount of force required to do a given amount of work, alter the direction of the force, or transform one form of motion or energy into another.
The mechanical advantage of a simple machine is the ratio between the force it exerts on the load and the input force applied. This does not entirely describe the machine's performance, as force is required to overcome friction as well. The mechanical efficiency of a machine is the ratio of the actual mechanical advantage (AMA) to the ideal mechanical advantage (IMA). Functioning physical machines are always less than 100% efficient.
Modern power tools, automated machine tools, and human-operated power machinery are tools that are also machines. Machines used to transform heat or other energy into mechanical energy are known as engines.
Hydraulics devices may also be used to support industrial applications, although devices entirely lacking rigid moving parts are not commonly considered machines. Hydraulics are widely used in heavy equipment industries, automobile industries, marine industries, aeronautical industries, construction equipment industries, and earthmoving equipment industries.

Ramjet

A ramjet, sometimes referred to as a stovepipe jet, is a form of jet engine that contains no major moving parts and can be particularly useful in applications requiring a small and simple engine for high speed use; such as missiles. They have also been used successfully, though not efficiently, as tipjets on helicopter rotors.

Jet engine

A jet engine is an engine that discharges a fast moving jet of fluid to generate thrust in accordance with Newton's third law of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets and pump-jets, but in common usage, the term generally refers to a gas turbine Brayton cycle engine, an engine with a rotary compressor powered by a turbine, with the leftover power providing thrust. Jet engines are so familiar to the modern world that gas turbines are sometimes mistakenly referred to as a particular application of a jet engine, rather than the other way around. Most jet engines are internal combustion engines but non combusting forms exist also.

Automotive fuses

Automotive fuses protect the wiring and electrical equipment for vehicles. They are generally rated for circuits no higher than 24 volts direct current.

Blade type
Plug-in fuses (also called blade or spade fuses), with a plastic body and two prongs that fit into sockets, are used in automobiles. These types of fuses come in three different physical dimensions: mini (or minifuse), ATO® (or ATC) and maxi (or maxifuse).The physical dimensions, including the connector, of the fuses are as follows (LxWxH) (ampere ratings in the parenthesis):
mini: 10.9x3.6x16.3 mm (2A, 3A, 4A, 5A, 7.5A, 10A, 15A, 20A, 25A, 30A)
ATO: 19.1x5.1x18.5 mm (1A, 2A, 3A, 4A, 5A, 7.5A, 10A, 15A, 20A, 25A, 30A, 40A)
maxi: 29.2x8.5x34.3 mm (20A, 30A, 40A, 50A, 60A, 70A, 80A)
It is possible to replace[8] an ATO-type plug-in fuse with a circuit breaker that has been designed to fit in the socket of a ATO-sized fuse holder. These circuit protectors are more expensive than a regular fuse.

Bosch type
Bosch type fuses are used in older (often European) automobiles. The physical dimension of this type of fuse is 6x25 mm with conical ends. Bosch type fuses usually use the same color coding for the rated current. The DIN standard is 72581/1

Color
Ampere
yellow
5A
white
8A
red
16A
blue
25A

Fuse Markings

Fuse Markings

A sample of the many markings that can be found on a fuse.

Surface Mount Fuses on 8 mm tape. Each fuse measures 1.6 mm x 0.79 mm and has no markings.
Most fuses are marked on the body, or end caps to markings[1] show their ratings. Surface mount technology"chip type" fuses feature little or no markings making identification very difficult.
When replacing a fuse, it is important to interpret these markings correctly as fuses that may look the same, could be designed for very different applications. Fuse markings will generally convey the following information;
Ampere rating of the fuse
Voltage rating of the fuse
Time-current characteristic ie. element speed
Approvals
Manufacturer / Part Number / Series
Breaking capacity

Fuse approvals
The majority of fuse manufacturers[2] build products that comply with a set of guidelines and standards, based upon the application of the fuse. These requirements are devised by many different Government agencies and certification authorities[3]. Once a fuse has been tested and proven to meet the required standard, it may then carry the approval marking of the certifying agency.
Fuse Packages
Fuses come in a vast array of sizes & styles[4] to cater for the immense number of applications in which they are used. Whilst many are manufactured in standardised package layouts to make them easily interchangeable, a large number of new styles are released into the marketplace every year. In terms of fuse body construction, ceramic is the most commonly used material. Glass & plastic are also used in lower voltage applications.
Cartridge (ferrule) fuses feature a cylindrical body terminated with metal end caps. Whilst most cartridge fuses are symmetrical, some cartridge fuses are manufactured with differing body proportions to reduce the possibility of inserting an incorrect fuse into the holder (circuit). An example of such a fuse range is the 'bottle fuse', which in appearance resembles the shape of a bottle.
Fuses designed for soldering to a printed circuit board traditionally featured wire leads that originated from the fuse body in a radial or axial configuration, however with the advancement of surface-mount technology, manufacturers have vastly reduced fuse body size and replaced the leads with solder pads.
Fuses used in higher voltage/ampere circuits as required by industrial applications, commonly feature metal tags or blades located on each end of the fuse. Tags allow the fuse to be bolted into the fuse holder whilst blades slot into metal pressure clamps located on the fuse holder. Blade type fuses often require the use of a special purpose extractor tool to remove them from the fuse holder.

Glass vs. Ceramic Construction
Whilst glass fuses have the advantage of a visible fuse element for inspection purposes, they have a low breaking capacity which generally restricts them to applications of 15 A or less at 250 VAC. Ceramic fuses have the advantage of a higher breaking capacity facilitating their use in higher voltage/ampere circuits. Filling a fuse body with sand provides additional protection against arcing in an overcurrent situation.

Measurements
Cartridge fuses[5] are generally measured as the overall length & diameter of the fuse. Due to the large variety of cartridge fuses available, fuse identification relies on accurate measurements as fuses can differ by only a few millimeters between types. 'Bottle style' cartridge fuses also require the measurement of the cap diameter as this varies between ampere ratings.
Other fuse packages can require a variety of measurements such as;
body (width x height x depth)
blade or tag (width x height x depth)
overall length of the fuse (when the fuse features blades or tags)
overall width of the fuse (when the fuse features 2 bodies)
width of the mounting holes (when the fuse features tags)
distance between blades (when radially configured)
fixing centre[6] (when the fuse features tags - see below)
Fuses fitted with tags require the fixing centre measurement. This measurement is the distance between the tag mounting holes on either end of the fuse as measured from the centre of each mounting hole.

Special Features
As visual identification of a blown fuse is only possible when the element is visible ie. glass body fuses, manufacturers have designed a variety of methods to indicate whether the fuse element is intact or blown such as;
Indicating pin: extends out of the fuse cap when the element is blown.
Indicating disc: a coloured disc (flush mounted in the end cap of the fuse) falls out when the element is blown.
Element window: a small window built into the fuse body to provide visual indication of a blown element.
Striker pin: similar to an indicating pin, but extends with more force to trip a switch when the element is blown.
Flag: an external sprung arm that is released to an extended position once the element is blown.
External trip indicator: similar function to striker pin, but can be externally attached (using clips) to a compatible fuse.
Some fuses allow a special purpose microswitch[7] or relay unit to be fixed to the fuse body. When the fuse element blows, the indicating pin extends to activate the micro switch or relay which in turn triggers an event.

fuse for electrical

Fuse (electrical)

In electronics and electrical engineering a fuse, short for 'fusible link', is a type of overcurrent protection device. Its essential component is a metal wire or strip that melts when too much current flows. When the metal strip melts, it opens the circuit of which it's a part, and so protects the circuit from excessive current.
A practical fuse was one of the essential features of Edison's electrical power distribution system. An early fuse was said to have successfully protected an Edison installation from tampering by a rival gas-lighting concern.
Fuses (and other overcurrent devices) are an essential part of a power distribution system to prevent fire or damage. When too much current flows through a wire, it may overheat and be damaged, or even start a fire. Wiring regulations give the maximum rating of a fuse for protection of a particular circuit. Local authorities will incorporate national wiring regulations as part of law. Fuses are selected to allow passage of normal currents, but to quickly interrupt a short circuit or overload condition.

Fuse characteristics

The speed at which a fuse operates depends on how much current flows through it. Manufacturers of fuses plot a time-current characteristic curve, which shows the time required to melt the fuse and the time required to clear the circuit for any given level of overload current.
Where several fuses are connected in series at the various levels of a power distribution system, it is very desirable to clear only the fuse (or other overcurrent device) electrically closest to the fault. This process is called "coordination" and may require the time-current characteristics of two fuses to be plotted on a common current basis. Fuses are then selected so that the minor, branch, fuse clears its circuit well before the supplying, major, fuse starts to melt. In this way only the faulty circuits are interrupted and minimal disturbance occurs to other circuits fed by the supplying fuse.
Where the fuses in a system are of similar types, simple rule-of-thumb ratios between ratings of the fuse closest to the load and the next fuse towards the source can be used.
Fuses are often characterized as "fast-blow" or "slow-blow" or "time-delay", according to the time they take to respond to an overcurrent condition. The selection of the characteristic depends on what equipment is being protected. Semiconductor devices may need a fast or ultrafast fuse for protection since semiconductors may have little capacity to withstand even a momentary overload. Fuses applied on motor circuits may have a time-delay characteristic, since the surge of current required at motor start soon decreases and is harmless to wiring and the motor.

Interrupting rating
A fuse also has a rated interrupting capacity, also called breaking capacity, which is the maximum current the fuse can safely interrupt. Generally this should be higher than the maximum prospective short circuit current. Miniature fuses may have an interrupting rating only 10 times their rated current. Fuses for small low-voltage wiring systems are commonly rated to interrupt 10,000 milliamperes. Fuses for larger power systems must have higher interrupting ratings, with some low-voltage current-limiting "high rupturing capacity" (HRC) fuses rated for 300,000 amperes. Fuses for high-voltage equipment, up to 115,000 volts, are rated by the total apparent power (megavolt-amperes, MVA) of the fault level on the circuit.

Voltage rating
As well as a current rating, fuses also carry a voltage rating indicating the maximum circuit voltage in which the fuse can be used. For example, glass tube fuses rated 32 volts should never be used in line-operated (mains-operated) equipment even if the fuse physically can fit the fuseholder. Fuses with ceramic cases have higher voltage ratings. Fuses carrying a 250 V rating may be safely used in a 125 V circuit, but the reverse is not true as the fuse may not be capable of safely interrupting the arc in a circuit of a higher voltage. Medium-voltage fuses rated for a few thousand volts are never used on low voltage circuits, due to their expense and because they cannot properly clear the circuit when operating at very low voltages.