Wednesday, August 27, 2008

Electrical connector


An electrical connector is a conductive device for joining electrical circuits together. The connection may be temporary, as for portable equipment, or may require a tool for assembly and removal, or may be a permanent electrical joint between two wires or devices. There are hundreds of types of electrical connectors. In computing, an electrical connector can also be known as a physical interface. Connectors may join two lengths of flexible wire or cable, or may connect a wire or cable to an electrical terminal.ContentsProperties of electrical connectorAn ideal electrical connector would have a low contact resistance and high insulation value. It would be resistant to vibration, water, oil, and pressure. It would be easily matedunmated, unambiguously preserve the orientation of connected circuits, reliable, carry one or multiple circuits. Desirable properties for a connector also include easy identification, compact size, rugged construction, durability capable of many connectdisconnect cycles, rapid assembly, simple tooling, and low cost. No single connector has all the ideal properties. The proliferation of types is a reflection of the differing importance placed on the design factors.edit Types of electrical connectorsA terminal is a simple type of electrical connector that connects two or more wires to a single connection point. Wire nuts are another type of single point connector.Terminal blocks of various types.Terminal blocks of various types.edit Terminal blocksTerminal blocks also called terminal boards or strips provide a convenient means of connecting individual electrical wires. They are usually used to connect wiring among various items of equipment within an enclosure or to make connections among individually enclosed items. Since terminal blocks are readily available for a wide range of wire sizes and terminal quantity, they are one of the most flexible types of electrical connector available. Some disadvantages are that connecting wires is more difficult than simply plugging in a cable and the terminals are generally not very well protected from contact with persons or foreign conducting materials.One type of terminal block accepts wires that are prepared only by removing stripping a short length of insulation from the end. Another type accepts wires that have ring or spade terminal lugs crimped onto the wires. Printed circuit board PCB mounted terminal blocks allow individual wires to be connected to the circuit board. PCB mounted terminal blocks are soldered to the board, but they are available in a pullapart version that allows the wireconnecting half of the block to be unplugged from the part that is soldered to the PCB.edit Crimpon terminalsMost types of crimpon terminals or lugs are attached to wires to allow the wires to be easily connected to screw terminals and faston or quickdisconnect terminals. There are also crimpon terminals for connecting two wires together either permanently or with disconnect capability. Crimpon terminals are attached by inserting the stripped end of a stranded wire into the tubular portion of the terminal. The tubular portion of the terminal is then compressed tightly around the wire or crimped by squeezing it with a special crimping pliers.edit Insulation displacement connectorsSince stripping the insulation from wires is timeconsuming, many connectors intended for rapid assembly use insulationdisplacement connectors so that insulation need not be removed from the wire. These generally take the form of a forkshaped opening in the terminal, into which the insulated wire is pressed and which cut through the insulation to contact the conductor within. To make these connections reliably on a production line, special tools are used which accurately control the forces applied during assembly. If properly assembled, the resulting terminations are gastight and will last the life of the product. A common example is the multiconductor flat ribbon cable used in computer disk drives to terminate each of the many approximately wires individually would be slow and errorprone, but an insulation displacement connector can terminate all the wires in literally one stroke. Another very common use is socalled punch down blocks used for terminating telephone wiring.





Insulation displacement connectors are usually used with small conductors for signal purposes and at low voltage. Power conductors carrying more than a few amperes are more reliably terminated with other means, though hot tap presson connectors find some use in automotive applications for additions to existing wiring.edit Plug and socket connectors male plug made by Amphenol.A male plug made by Amphenol.Plug and socket connectors are usually made up of a male plug and a female socket, although hermaphroditic connectors exist, such as the original IBM token ring LAN connector. Plugs generally have one or more pins or prongs that are inserted into openings in the mating socket. The connection between the mating metal parts must be sufficiently tight to make a good electrical connection and complete the circuit. When working with multipin connectors, it is helpful to have a pinout diagram to identify the wire or circuit node connected to each pin.conductor hermaphrodite connector for tokenring attachment.conductor hermaphrodite connector for tokenring attachment.Detail of mating surfaces of hermaphrodite connector.Detail of mating surfaces of hermaphrodite connector.Transistor switch module with large screw connectors and small faston connectors.Transistor switch module with large screw connectors and small faston connectors.edit Component and device connectorsElectrical and electronic components and devices sometimes have plug and socket connectors or terminal blocks, but individual screw terminals and faston or quickdisconnect terminals are more common. Small components have bare lead wires for soldering. They are manufactured using castingedit Commonly used connectorsedit PC connectorPC Connector crimped to cablePC Connector crimped tocable Main article PCPC is short for eight positions, eight conductors, and so an PCmodular connector plug or jack is a modular connector with eight positions, all containing conductors. The PC modular plugs and jacks look very similar to the plugs and jacks used for FCCs registered jack RJ variants, although the true and extremely uncommon RJ is not really compatible with PC modular connectors. It neither uses all eight conductors but only two of them for wires plus two for shorting a programming resistor nor does it fit into PC because the true RJ is keyed. The connector is probably most famous for its use in Ethernet and widely used on CAT cables.edit Dsubminature connectors male DE plug.A male DE plug.The Dsubminiature electrical connector is commonly used for the RS serial port on modems and IBM compatible computers. The Dsubminiature connector is used in many different applications, for computers, telecommunications, and test and measurement instruments. A few examples are monitors MGA, CGA, EGA, the Commodore , MSX, Apple II, Amiga and Atari joysticks and mice, and game consoles such as Atari, Sega and Amiga.

USB connectors


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Main article USBA male USB series A plugA male USB series A plugThe Universal Serial Bus is a serial bus standard to interface devices, founded in . It is currently widely used among PCs, Apple Macintosh and many other devices. There are several types of USB connectors, and some have been added as the specification has progressed. The most commonly used is the male series A plug on peripherals, when the cable is fixed to the peripheral. If there is no cable fixed to the peripheral, the peripheral always needs to have a USB B socket. In this case a USB A plug to a USB B plug cable would be needed. USB A sockets are always used on the host PC and the USB B sockets on the peripherals. It is a pin connector, surrounded by a shield. There are several other connectors in use, the miniA, mini B and miniAB plug and socket added in the OnTheGo Supplement to the USB . Specification.edit Power connectorsSee Domestic AC power plugs and sockets, NEMA connectors, Industrial and multiphase power plugs and sockets for discussions of connectors used for electric power. Power connectors must protect people from accidental contact with energized conductors. Power connectors often include a safety ground connection as well as the power conductors. In larger sizes, these connectors must also safely contain any arc produced when an energized circuit is disconnected or may require interlocking to prevent opening a live circuit.edit Radio frequency connectorsConnectors used at radio frequencies must not change the impedance of the transmission line of which they are part, otherwise reflections and losses will result. A radiofrequency connector must not allow external signals into the circuit, and must prevent leakage of energy out of the circuit. At lower radio frequencies simple connectors can be used with success, but as the radio frequency increases so that the dimensions of the connector are getting close to a small fraction of one wavelength, connector design becomes increasingly critical. At UHF and above, silverplating of connectors is common to reduce losses.For WiFi antennae the RTNC connectors are used. A BNC connector is commAudio and video connectorFrom Wikipedia, the free encyclopediaump to navigation, searchRCA connectors are commonly used for home stereo and video equipment.RCA connectors are commonly used for home stereo and video equipment.Audio connectors and video connectors are electrical connectors for carrying an audio signal or video signal, either in an analog or digital format. Analog AV connectors often use Shielded cable to inhibit RF interference and noise.Highend audio cables are claimed to improve the sound quality of highfidelity audio systems but whether they actually do is hotly disputed. Since the audio signal passes through cables on its way from the source to the amplifier, or from the amplifier to the speakers, the cables will affect that signal. Basic system frequency response can be calculated from the electrical properties of the cables, and components on either side of the cables. These electrical properties include resistance, capacitance, and inductance. For smallsignal applications the degree of shielding are also important. All of these qualities are taken into account in the design of commercial and broadcast cables. Highend cables for the audiophile market often involve intricate construction geometries and exotic materials such as silver and oxygenfree, longcrystal, highpurity copper.ontroversyThere is controversy among audiophiles surrounding the impact that highend cables have on audio systems. The audibility of the changes is a matter of much debate. There are claims that, even among audiophiles, in a doubleblind test it is difficult or impossible to distinguish extremely expensive, exotic speaker cables from ordinary lamp cords or budget AWG copper speaker wire.





James Randi, a stage magician and scientific skeptic best known as a challenger of paranormal claims and pseudoscience, offered a prize of one million dollars to anyone who could prove his or her ability to distinguish an expensive highend audio cable from an ordinary audio cable by means of a controlled listening test. Michael Fremer of the Stereophile magazine took the challenge, but satisfactory testing conditions could not be agreed upon, and the test did not take place.Blind and independent testing conducted by Lee Gomes of the Wall Street Journal demonstrated that % of people tested at an audio show could differentiate between low end and high end speaker cables. Lee Gomes remarked, That may not be much of a margin for two products with such drastically different prices, but I was struck by how the bestinformed people at the show like John Atkinson and Michael Fremer of Stereophile Magazine asily picked the expensive cable.edit Digital cablesOne of the more contentious areas is in digital cable design, with high end cables being sold with claims of distortionfree signal transfer. Some have argued that since the bit rates approximately Mbits and distance traveled are considerably lower than for other data transfer technologies such as gigabit ethernet, any cable appropriately matched to the correct impedance requirement is sufficient. Others claim that jitter caused by imperfect impedance matching is very detrimental to the audio signal and the most substantial shortcoming of digital audio. This has led equipment manufacturers to design new standards such as I²S which separates clock and data signals or implement buffering and reclocking, although such standards are typically aimed at synchronising multiple signals to a single clock rather than attempting to correct errors due to jitter.It is also worth noting that in independent testing, digital audio, at least of the SPDIF sound format has been shown to be carried perfectly well over any length of wire of nearly any quality, including wire as simple as a coat hanger. Similar tests have not yet shown similar situation for analogue audio however.edit Speaker cablesAnother area of debate is speaker cables. Skeptics say that a few meters of cable from the power amplifier to the binding posts of the loudspeakers cannot possibly have much influence because of the complex crossover circuits found in most speakers and partirly speaker driver voice coils with several meters of wire.A global concern with speaker cables is their inherent impedance relative to the impedance of the loudspeaker. Low impedance speakers are claimed to benefit most from low impedance cabling this means thicker andor shorter wires. It is claimed that longer cable runs need to be even thicker to minimize signal loss.DsubminiatureFrom Wikipedia, the free encyclopediaJump to navigation, searchDA, DB, DC, DD, and DE sized connectorsDA, DB, DC, DD, and DE sized connectorsThe Dsubminiature or Dsub is a common type of electrical connector used particularly in computers. Calling them subminiature was appropriate when they were first introduced, but today they are among the largest common connectors used in computers.Description and nomenclatureThe DBW Connector with coaxial connections and ten ordinary pinsThe DBW Connector with coaxial connections and ten ordinary pinsMale W PlugMale W PlugA Dsub contains two or more parallel rows of pins or sockets usually surrounded by a Dshaped metal shield that provides mechanical support and some screening against electromagnetic interference. The D shape guarantees correct orientation. The part containing pin contacts is called the male connector or plug, while that containing socket contacts is called the female connector or socket. The sockets shield fits tightly inside the plugs shield. The shields are connected to the overall screens of the cables when screened cables are used, creating an electrically continuous screen coering the whole cable and connector system.Dsubminiature connectors were invented by ITT Cannon, part of ITT Corporation, in . Cannons partnumbering system uses a D as the prefix for the whole series, followed by a letter denoting the shell size A= pin, B= pin, C= pin, D= pin, E= pin, followed by the actual number of pins, followed by the gender P=plug, S=socket. For example, DB denotes a Dsub with a position shell size and a position contact configuration. The contacts in these connectors are spaced approximately . inches . mm apart with the rows spaced . inches . mm apart.

Cannon also produced Dsubs

Cannon also produced Dsubs with larger positions in place of some of the normal pin positions that could be used for either highcurrent, highvoltage, or coaxial inserts. The DBW variant was commonly used for highperformance video connections this variant provided regular # pins plus three coaxial contacts for the red, green, and blue video signals.In the photograph below, the connector on the left is a pin DE connector plug, and the one on the right is a pin DB socket. The hexagonal pillars at either end of each connector have a threaded stud not visible that passes through flanges on the connector, fastening it to the metal panel. They also have a threaded hole that receives the jackscrews on the cable shell, to hold the plug and socket together.Possibly because the original PC used DB connectors for the serial and parallel ports, many people, not knowing the significance of the letter B as the shell size, began to call all Dsub connectors DB connectors instead of specifying DA, DC or DE. When the PC serial port began to use pin connectors, they were often called DB instead of DE. It is now common to see DE connectors sold as DB connectors. DB is nearly always intended to be a pin connector with an E size shell.There are now Dsub connectors which have the original shell sizes, but more pins, and the names follow the same pattern. For example, the DE, usually found in VGA cables, has pins, in three rows, in an E size shell. The full list of connectors with this pin spacing is DE, DA, DB, DC, and DD. Alternatively, following the same confusion mentioned above in which all Dsub connectors are called DB, these connectors are often called DBHD, DBHD, DBHD, DCHD, and DDHD, where the HD stands for high density. They all have rows of pins, except the DD, which has .A series of Dsub connectors with even denser pins is called double density, and consists of DE, DA, DB, DC, and DD. They have rows of pins.There is yet another similar family of connectors that is easy to confuse with the Dsub family, but is not part of it. These connectors have names like HD and HD, and have a Dshaped shell but the shell is about half the width of a DB. They are common in SCSI attachments. sometimes used instead of the original P and S plug and socket.The original Dsubminiature connectors are now defined by an international standard, DIN .dit Typical applicationsDsub connectors. Left DEM Right DBF.Dsub connectors.Left DEM Right DBF.The widest application of Dsubs is for RS serial communications, though the standard did not make this connector mandatory. RS devices originally used the DB pin Dsub, but for many applications the less common signals were omitted, allowing a DE pin Dsub to be used.On PCs, pin and pin plugs are used for the RS serial ports and pin sockets are used for the parallel printer ports instead of the Centronics socket found on the printer itself. pin sockets on Macintosh computers are typically SCSI connectors again in contrast to the Centronics C connector typically found on the peripherial.A male DE connector on the back of an IBMPCcompatible computer is typically a serial port connector. IBM introduced the DE connector for RS on PCs with the Personal Computer AT in . A female pin connector on the same computer may be a video display output monochrome, CGA, or EGA. Even though these all use the same connector, the displays cannot all be interchanged and monitors or video interfaces may even be damaged if connected to an incompatible device using the same connector. Later analog video VGA and later adapters replaced these connectors by DE pin highdensity sockets, which have three rows of five contacts each in the space that was previously occupied by two rows of five and four contacts. Other common names for DE connectors are HD, where HD stands for High Density, and less accurately DB and DBHD.

From the late s and all through the s, DEs without the pair of fastening screws were almost universal as game controller connectors on video game consoles and home computers, after being made a de facto standard by the use of such game ports in the Atari game console and the Atari bit family of computers. Computer systems which use them include Atari, Commodore, Amiga, Amstrad, and SEGA systems, among others, but exclude Apple and PC systems and most newer game consoles. Used in the standard way, they support one digital joystick and one pair of analog paddles on many systems a computer mouse or a light pen is also supported through these sockets, however these mice are not usually exchangeable between different systems. DE connectors are also used for some token ring and other computer networks. DA is used for Ethernet Attachment Unit Interface.Many uninterruptible power supply units have a DEF connector on them, in order to signal to the attached computer. Often these do not send data serially to the computer but instead use the handshaking control lines to indicate low battery, power failure or other conditions. Such usage is not standardized between manufacturers and may require special cables to be supplied.A male PCBmounting DD dsub connectorA male PCBmounting DD dsub connectorThe complete range of Dsub connectors also includes pin DAs two rows of and pin DCs two rows of and and pin DDs two rows of and one of , the last two being used in industrial products. The pin DA has been notably used for color video output on early Macintosh computers and as the IBMdefined analogue joystick port on PCs where it is female. Many thirdparty PC sound cards, particularly the Sound Blaster line from Creative Labs, included a variation of the IBM joystick port using the same connector but taking two of the pins to add a usually MPU compatible MIDI interface. The DAF was also used for the AUI connectors included on Ethernet cards in the s and s, albeit with a sliding latch to lock the connectors together instead of the usual hex studs with threaded holes. Finally, the early Macintosh and Apple II line of computers used a very rare pin Dsub for connecting to external floppy disk drives, and the Commodore Amiga used an unusual pin version for both its video output and for connecting an external floppy drive. male DE connector.A male DE connector.A diagram of a DE plugTASCAM used DB connectors for their multitrack recording audio equipment TDIF, and Logitek Audio later did the same for its broadcast consoles, though with different pinouts. A few patch panels have been made which have the DB connectors on the back with phone jacks or even TRS jacks on the front, however these are normally wired for TASCAM, which is more common outside of broadcasting.In broadcast and professional video, parallel digital is a digital video interface that utilizes DB connectors, per the SMPTE M specification adopted in the late s. The more common SMPTE M serial digital interface SDI utilizes BNC connectors for digital video signal transfer.edit Types and variantsDsub connectors exist in at least five types, differentiated by the method used to attach wires to the contacts. These are soldercup or solderbucket, insulation displacement, crimp, PCB pins, and wire wrap. Solderbucket contacts have a cavity into which the stripped wire is inserted and handsoldered a somewhat tricky process especially to do alone as the wire can easily pop out of the bucket whilst soldering unless held there. Insulation displacement contacts IDC allow a ribbon cable to be forced onto sharp tines on the back of the contacts this action pierces the insulation of all the wires simultaneously. This is a very quick means of assembly whether done by hand or automatically but requires use of flat ribbon cable which can be awkward to handle and makes it difficult to make cables with different connections at each end.Crimp contacts are assembled by inserting a stripped wire end into a cavity in the rear of the contact, then crushing the cavity using a crimp tool causing it to grip the wire tightly at many points. The crimped contact is then inserted into the connector where it locks into place. Individual crimped pins can be removed later with a tool inserted into the rear of the connector. This rear release feature is valuable when pins are damaged or modifications must be made to the circuits. PCB pins as the name suggests are intended to be soldered directly to a printed circuit board and not to a wire. These connectors are frequently mounted at a rightangle to the PCB allowing a cable to be plugged into the edge of the PCB assembly. Blocks containing multiple stacked D connectors and sometimes other connectors too are nearly always seen on ATX or variants thereof PC motherboards but arent generally seen elsewhere. Wire wrap connections are made by wrapping solid wire around a square post with a wire wrap tool. This type of connection is usually used in prototyping.A smaller type of connector derived from the Dsubminiature, and about half the linear size, is called the microminiature D, or microD, which is a trademark of ITT Cannon. This connector is used in industrial instrumentation products. A few manufacturers make nanoD connectors, which are about half the size again.

Usage

The pin DSub connector has become the standard in the recording studio industry for multichannel analog audio and AES Digital audio.The Dsub connector family is now in decline for general usage in the computer industry, for several reasons cost, size, and lack of flexibility. For portable devices such as PDAs, MP players or mobile phones, the Dsub connector is usually too large to fit. Many laptop computers, where weight and size are crucial, no longer include Dsubs. Even small form factor desktop PCs may find Dsub connectors too large for their value.Because of the relatively complex shapes and assembly, especially the shaped metal D shield, and screws and nuts for physical securing, Dsub connectors are now quite expensive compared to other common connectors, which are mostly simpler. In the retail PC world where margins are very thin, these connectors are a natural target for removal.The physical design is not friendly to plugandplay applications. Thin metal pins, especially in higherdensity connectors, are easily bent or broken, especially when frequently plugged in blind behind equipment. Although ESD and EMI resistant Dsub connectors exist, the fundamental design was never intended to protect from electrostatic discharge or electromagnetic interference or facilitate very high frequency interconnections.For video purposes, the DEHD connector is being slowly replaced by DVI and HDMI connectors, although this transition is proceeding more slowly, since many analog CRT monitors are still in use and the digital DVI connector is not useful for those.For the majority of other consumer applications, Dsub serial and parallel connectors have been replaced by IEEE FireWire, SATA, USB or Ethernet connections.edit See also Gender of connectors and fasteners RS Technical Manual RJ MMJ commonly banana plug for the male, banana jack for the female is a singlewire one conductor electrical connector used for joining wires to equipment. The plugs are frequently used to terminate patch cords for electronic test equipment. They are also used as the plugs on the cables connecting the amplifier to the loudspeakers in a hifi sound system.The plug was invented in by Richard Hirschmann former Richard Hirschmann GmbH & Co..The plug consists of a cylindrical metal pin about mm one inch long, with a diameter of mm, which can be inserted into a matching mm socket to make an electrical contact. While it is also called a mm connector likewise mm plug or mm jack, as above, there are also other sizes used for other applications. The pin has one or more lengthwise springs that bulge outwards slightly. These press against the sides of the socket, improving the electrical contact and preventing the pin from falling out. The curved profile of these springs is probably the origin of the name banana plug. The other end of the plug has a hole that accepts a length of flexible insulated equipment wire, which is either screwed or soldered into place. An insulating plastic cover is usually fitted over this end.The wide end of a mm plug often has a mm hole drilled in it, either transversely or axially, to accept the pin of another mm plug. This type is called a stackable mm plug.For high voltage use, a special sheathed version of the banana plug and socket is used. This version has an insulating sheath around both the male and female connectors to avoid accidental contact. The sheathed male plug will not work with an unsheathed female socket, but an unsheathed male plug will fit a sheathed female socket.The plastic housing is often extended to contain two banana plugs, allowing simultaneous connection of a signal line and a ground earth line see the photo. The housing may allow the connection of individual wires, a permanently attached coaxial cable providing both signal and ground, or a coaxial connector such as the BNC connector shown in the photo. By convention, multiple fullsized banana connectors are spaced on ¾ inch centers.Individual banana plugs and jacks are commonly colorcoded red and black but are available in a wide variety of colors. Dual banana plugs are usually black with some physical feature such as a molded ridge marked Gnd indicating the relative polarity of the two plugs.Besides plugging into specific banana jacks, banana plugs may plug into fiveway or universal binding posts on audio equipment.edit Miniature connectorsA miniaturized version of the banana connector was also produced. About the size of the standard connector, these were useful in highdensity applications but never achieved the same sort of popularity as the larger banana connectors. They are substantially more fragile than the larger connectors. Multiple miniature banana connectors are usually spaced on ½ inch centers.

Electrical safetyAn exposed banana plug can obviously present electrical hazards if the wire to which it is attached is energized. The hazards include electric shock, electrocution, burns from accidental short circuits, and damage to the attached equipment. Where electrical safety is an issue, due to the presence of higher voltages andor currents, various kinds of protected plugs and sockets are available. These have sliding covers on plugs andor other devices to protect the user from accidental contact with live conductors, but are still largely compatible with the original design.A typical design is now required on digital voltmeter test leads. In this design, the metal banana plug is entirely sheathed in plastic and presses into a deep recess in the DVM. Alternatively, the DVM has the male part of the banana plug and it is deeply recessed the test lead contains a sheathed banana jack.In parts of Europe where the standard mains power connector is the Schuko connector, it can be difficult to purchase USstyle double banana plugs. The standard US pin spacing of inch is very close to the Schuko spacing of mm. It is easy to insert a double banana into a Schuko power outlet, leading to a risk of electrical shock.mechanical trades and manufacturing, each of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. The assignment is by direct analogy with genitalia and sexual intercourse the part bearing one or more protrusions, or which fits inside the other, being designated male and the part containing the corresponding indentations or fitting outside the other being female.DefinitionsThe terms slot, socket, receptacle and outlet are often used for female connectors, and plug, prong or pin for male connectors. In many cases these terms are more common than male and female, especially in documentation intended for the nonspecialist. It also causes a fair amount of confusion when those names are shortened in labels. For example, the male component of an HD connector can be named either HDM or HDP HDF or HDS for female versions, both of which mean the same thing but could be confused for different items when there is no accompanying picture. Further confusion can be caused by the term jack, which is used for both female and male connectors.IEEE STD and ANSI Y. define plug and jack by location or motion, rather than gender. A connector in a fixed location is a jack, and a moveable connector is a plug. The distinction is relative, so a portable radio is considered stationary compared to the cable from the headphones the radio has a jack, and the headphone cable has a plug. It is common practice to use female connectors for jacks, so the informal genderbased usage often agrees with the functional description of the technical standards. This is not always the case, so it is best to use male and female for gender, and plug and jack for function.edit SafetyIn electrical connections where voltage is sufficient to cause injury, the part connected to the power source is invariably female, to prevent inadvertent contact. A plug is on the cord of or on the device drawing the power.In lowvoltage use, such as for data communications, this is less important, and male or female connectors are used based on other engineering factors such as convenience of use or ease of manufacturing. For example, the common patch cables used for Ethernet hookups and the similar cords used for telephones typically have plugs on both ends, to connect to jacks on equipment or mounted in walls. A device called a gender changer may be used to join two connectors of the same gender, for example, to extend one video cable with another.The gender of a connector is determined by the structure of its primary functional components — i.e., the conductors of an electrical connector, or the loadbearing parts of a fastener — and not by secondary features such as covers, shields or handles that may be installed for environmental protection, safe operation, etc.

Genderless connectors

Certain connector designs such as the SAE connector, and jackhammer air hose connectors involve paired identical parts each containing both protrusions and indentations. The term hermaphrodite or hermaphroditic is used for such devices, along with genderless, combination and combo, twoinone, twoway, and others.Some connectors have both male and female connectors on opposite sides, designed to be placed between a male and female to intercept a signal or to take power. These may also be referred to as hermaphrodite connectors, or alternately vampire or parasite plugs. These were once used for PC accessories, placed between the output of an AT power supply and a monitor so these accessories would be disconnected from power when the computer was switched off, but are now impractical with the dominance of ATX supplies which lack a mains output socket.edit ExamplesMale coaxial Type N connector.Male coaxial Type N conntor. A power cord on a appliance terminates in a male plug it connects to a female socket in a wall or on an extension cord.Coaxial cables used for video or other highfrequency signals are normally tenated, at both ends, in a connector comprising an inner pin and an outer fixed or rotating shell these are conventionally reckoned as male. A nut is female and a bolt is male.Connectors for air brake hoses on heavy trucks and railroad equipment use genderless gladhand connectors. In railroad use, this makes the orientation of rolling stock irrelevant, and is used with the standard North American railroad coupler that connects cars together, also genderless. Piping an plumbing fittingsedit See alsoScrew threadFrom Wikipedia, the free encyclopediaJump to navigation, searchInternal and external threads illustrated using a common nut and bolt. The screw and nut pair can be used to convert torque into linear force. As the screw or bolt is rotated, the screw moves along its axis through the fixed nut, or the nonrotating nut moves along the leadscrew.Internal and external threads illustrated using a common nut and bolt. The screw and nut pair can be used to convert torque into linear force. As the screw or bolt is rotated, the screw moves along its axis through the fixed nut, or the nonrotating nut moves along the leadscrew.Screw thread, used to convert torque into the linear force in the flood gate. The operator rotates the two long vertical bolts via bevel gear.Screw thread, used to convert torque into the linear force in the flood gate. The operator rotates the two long vertical bolts via bevel gear.A screw thread is a helical or tapered structure used to convert between rotational and linear movement or force.A screw thread may be thought of as an inclined plane wrapped around a cylinder or cone. The tightening of a fasteners screw thread is comparable to driving a wedge into a gap until it sticks fast through friction and slight plastic deformation.In most applications, the thread pitch of a screw is chosen so that friction is sufficient to prevent linear motion being converted to rotary, that is so the screw does not slip even when linear force is applied so long as no external rotational force is present. This characteristic is essential to the vast majority of its uses.Screw threads have several applications FasteningFasteners such as wood screws, machine screws, nuts and bolts. Connecting threaded pipes and hoses to each other and to caps and fixtures. Gear reduction via worm drives Moving objects linearly by converting rotary motion to linear motion, as in a screw jack. Measuring by correlating linear motion to rotary motion and simultaneously amplifying it, as in a micrometer. Both moving objects linearly and simultaneously measuring the movement, combining the two aforementioned functions, as in a leadscrew.

In all of these applications, the screw thread has two main functions It converts rotary motion into linear motion. It prevents linear motion without the corresponding rotation.Contentshide Standard threads ISO standard threads . Other current standardsistory of standardizationEngineering drawingGenerating screw threads Thread cutting Thread rolling Thread forming Thread casting Thread grinding Thread lapping Examples See also Notes ReferencesExternal linksedit Standard threadsStandards for machine screw threads have evolved since the early nineteenth century to facilitate compatibility between different manufacturers and users. Many of these standards also specified corresponding bolt head and nut sizes, to facilitate compatibility between spanners and other driving tools.Nearly all threads are oriented so that a bolt or nut, seen from above, is tightened the item turned moves away from the viewer by turning it in a clockwise direction, and loosened the item moves towards the viewer by turning anticlockwise. This is known as a righthanded thread, since the natural screwing motion for a righthanded person is clockwise, and is the default because most people are righthanded. Threads oriented in the opposite direction are known as lefthanded. There are also selftapping screw threads where no nut is required.efthanded threads are used Where the rotation of a shaft would cause a conventional righthanded nut to loosen rather than to tighten due to fretting induced precession, e.g. on a lefthand bicycle pedal. In combination with righthanded threads in turnbuckles. In some gas supply connections to prevent dangerous misconnections, for example in gas welding the flammable gas supply uses lefthanded threads.In some instances, for example early ballpoint pens, to provide a secret method of disassembly.In some applications of a leadscrew, for example the cross slide of a lathe, where it is desirable for the cross slide to move away from the operator when the leadscrew is turned clockwise.Unless stated otherwise, all standards below specify righthanded threads.edit ISO standard threadsThe most common threads in use are the ISO metric screw threads M and BSP threads also called G threads for pipes.These were standardized by the International Organization for Standardization in . Before that, there were separate metric thread standards used in France, Germany, and Japan, and the Swiss had a set of threads for watches.edit Other current standardsIn particular applications and certain regions, threads other than the ISO metric threads remain commonly used. This is largely for reasons of backwards compatibility. NonISO threads in common use include Unified Thread Standard, UTS, which is still the dominant thread type in the United States and Canada. This standard includes Unified Coarse UNC Unified Fine UNF Unified Extra Fine UNEF Uniied Special UNS National pipe thread NPT British Standard Whitworth BSW, and for other Whitworth threads includingBritish Standard Fine BSF Cycle Engineers Institute CEI British standard pipe thread BSPBritish Standard Pipe Taper BSPT British Association screw threads BA, primarily electriceectrical, moving coil meters and to mount optical lenses Camera case screws, used to mount a camera on a photographic tripod British Standard Whitworth BSW used on almost all small cameras BSW for larger and some older small cameras Royal Microscopical Society RMS thread, a special . thread used for microscope objective lenses. Microphone stands threads per inch tpi Unified Special thread UNS, USA and the rest of the worldBSW not common in the USA, used in the rest of the world BSW not common in the USA, used in the rest of the world Stage lighting suspension bolts in some countries only some have gone entirely metric, others such as Australia have reverted to the BSW threads, or have never fully converted BSW for lighter luminaries BSW for heavier luminariesPanzergewinde Pg also StahlpanzerrohrGewinde is an old German ° thread DIN that remained in use until in some electrical installation accessories in Germany.

History of standardization

Graphic representation of formulas for the pitches of threads of screw boltsGraphic representation of formulas for the pitches of threads of screw boltsThe first historically important intracompany standardization of screw threads began with Henry Maudslay around , when the modern screwcutting lathe made interchangeable screws a practical commodity. During the next years, standardization continued to occur on the intracompany and intercompany level. In , Joseph Whitworth created a design that, through its adoption by many British railroad companies, became a national standard for the United Kingdom called British Standard Whitworth. During the s through s, this standard was often used in the United States and Canada as well, in addition to myriad intra and intercompany standards. In April , William Sellers presented a paper to the Franklin Institute in Philadelphia, proposing a new standard to replace the U.S.s poorly standardized screw thread practice. Sellers simplified the Whitworth design by adopting a thread profile of ° and a flattened tip in contrast to Whitworths ° angle and rounded tip. The ° angle was already in common use in America, but Sellerss system promised to make it and all other details of threadform consistent.The Sellers thread, easier for ordinary machinists to produce, became an important standard in the U.S. during the late s and early s, when it was chosen as a standard for work done under U.S. government contracts, and it was also adopted as a standard by highly influential railroad industry corporations such as the Baldwin Locomotive Works and the Pennsylvania Railroad. Other corporations adopted it, and it soon became a national standard for the U.S., later becoming generally known as the United States Standard. Over the next years the standard was further defined and extended and evolved into a set of standards including National Coarse NC, National Fine NF, and National Pipe Taper NPT.For a good summary of screw thread standards in current use in , see Colvin FH, Stanley FA eds American Machinists Handbook, nd ed. New York and London McGrawHill, pp. .For a good summary of screw thread standards in current use in , see Colvin FH, Stanley FA eds American Machinists Handbook, nd ed. New York and London McGrawHill, pp. .During this era, in continental Europe, the British and American threadforms were well known, but also various metric thread standards were evolving, which usually employed ° profiles. Some of these evolved into national or quasinational standards. They were mostly unified in by the International Congress for the standardization of screw threads at Zurich, which defined the new international metric thread standards as having the same profile as the Sellers thread, but with metric sizes. Efforts were made in the early th century to convince the governments of the U.S., UK, and Canada to adopt these international thread standards and the metric system in general, but they were defeated with arguments that the capital cost of the necessary retooling would damage corporations and hamper the economy. The mixed use of dualling inch and metric standards has since cost much, much more, but the bearing of these costs has been more distributed across national and global economies rather than being borne up front by particular governments or corporations, which helps explain the lobbying efforts.During the late th and early th centuries, engineers found that ensuring the reliable interchangeability of screw threads was a multifaceted and challenging task that was not as simple as just standardizing the major diameter and pitch for a certain thread. It was during this era that more complicated analyses made clear the importance of variables such as pitch diameter and surface finish. Classes of fit were standardized, and new ways of generating and inspecting screw threads were developed such as production threadgrinding machines and optical comparators.

Problems with lack of interchangeability among American, Canadian, and British parts during World War II led to an effort to unify the inchbased standards among these closely allied nations, and the Unified Thread Standard was adopted by the Screw Thread Standardization Committees of Canada, the United Kingdom, and the United States on November , in Washington, D.C., with the hope that they would be adopted universally. The original UTS standard may be found in ASA now ANSI publication, Vol. , . UTS consists of Unified Coarse UNC, Unified Fine UNF, Unified Extra Fine UNEF and Unified Special UNS. The standard was not widely taken up in the UK, where many companies continued to use the UKs own British Association BA standard.However, internationally, the metric system was eclipsing inchbased measurement units. In , the International Organization for Standardization interlingually known as ISO had been founded and in , the metricbased International System of Units abbreviated SI from the French Système international was created. With continental Europe and much of the rest of the world turning to SI and the ISO metric screw thread, the UK gradually leaned in the same direction. The ISO metric screw thread is now the standard that has been adopted worldwide and has mostly displaced all former standards, including UTS. In the U.S., where UTS is still prevalent, over % of products contain at least some ISO metric screw threads. The UK has completely abandoned its commitment to UTS in favour of the ISO metric threads, and Canada is in between. Globalization of industries produces market pressure in favor of phasing out minority standards. A good example is the automotive industry U.S. auto parts factories long ago developed the ability to conform to the ISO standards, and today very few parts for new cars retain inchbased sizes, regardless of being made in the U.S.edit Engineering drawingIn American engineering drawings, ANSI Y. defines standards for indicating threaded parts. Parts are indicated by their nominal diameter the nominal major diameter of the screw threads, pitch number of threads per inch, and the class of fit for the thread. For example, “.UNCA” is male A with a nominal major diameter of .?, threads per inch, and a class fit “.UNFB” would be female B with a .? nominal major diameter, threads per inch, and a class fit. An arrow points from this designation to the surface in question.edit Generating screw threadsPage of Colvin FH, Stanley FA eds American Machinists Handbook, nd ed. New York and London McGrawHill. Summarizes screw thread rolling practice as of .Page of Colvin FH, Stanley FA eds American Machinists Handbook, nd ed. New York and London McGrawHill. Summarizes screw thread rolling practice as of .here are various methods for generating screw threads. The method chosen for any one application is chosen based on constraints—time money degree of precision needed or not needed what equipment is already available what equipment purchases could be justified based on resulting unit price of the threaded part which depends on how many parts are planned etc.In general, certain threadgenerating processes tend to fall along certain portions of the spectrum from toolroommade parts to massproduced parts, although there can be considerable overlap. For example, thread lapping following thread grinding would fall only on the extreme toolroom end of the spectrum, while thread rolling is a large and diverse area of practice that is used for everything from microlathe leadscrews somewhat pricey and very precise to the cheapest deck screws very affordable and with precision to spare.The various methods are summarized below.

Thread cutting

The excess material is cut away, with taps and dies for most smaller diameters, or with singlepoint threadcutting on a lathe for larger ones or smaller ones needing very high concentricity.edit Thread rollingThe material is extruded into a male thread through mechanical pressure as the screw blank is rolled between a matched pair of flat dies. See Cold forming. Thread rolling is more common for highvolume production, and produces threads of diameters typically smaller than one inch. Also, materials with good deformation characteristics are better used with rolling these materials include softer more ductile metals and exclude brittle materials, such as cast iron. A rolled thread can often be easily recognized because the thread has a larger diameter than the blank rod from which it has been made. However, necks and shoulders can be cut or rolled to different diameters, so this in itself is not a forensic giveaway. Also, the end of the screw usually looks a bit different from the end of a cutthread screw. Rolled male threads tend to be slightly stronger than cut male threads. Thread rolling is a very economical way of producing large quantities with good dimensional accuracy. The cost of thread rolling depends on the quantity the more parts made, the cheaper the unit cost.edit Thread formingThis is the femalethread analogue of the malethreadrolling process described above. The material is extruded into a thread through mechanical pressure by a tap that is similar to a cutting tap except that it has no flutes. Instead of cutting, the tap squeezes the material out of its way. Formed female threads tend to be slightly stronger than cut female threads.This process is more often employed in soft, ductile metals such as aluminum than in hard, brittle metals such as cast iron.edit Thread castingThe threads take the shape of whatever mold or die that the liquid or gas material is poured into. When the material freezes into a solid, it retains the shape. Material is either heated to a liquid or rarely a gas, or mixed with a liquid that will either dry or cure such as plaster or cement. Alternately, the material may be forced into a mould as a powder and compressed into a solid, as with graphite.Cast threads in metal parts may be finished by machining, or may be left in the ascast state. The same can be said of cast gear teeth. Whether or not to bother with the additional expense of a machining operation depends on the application. For parts where the extra precision and surface finish is not strictly necessary although it might be nice, the machining is forgone in order to achieve a lower cost. With sand cast parts this means a rather rough finish but with molded plastic or diecast metal, the threads can be very nice indeed straight from the mold or die.edit Thread grindingThread grinding is done on cylindrical grinders using specially dressed wheels matching the shape of the threads. Although expensive, threads produced by grinding are highly accurate and have a very fine surface finish with applications such as ball screw mechanisms used for precise movement of machine components.Technically, thread grinding is a subset of thread cutting, as grinding is a true metalcutting process. Each grain of abrasive functions as a microscopic singlepoint cutting edge although of high negative rake angle, and shears a tiny chip that is analogous to what would conventionally be called a cut chip turning, milling, drilling, tapping, etc.. However, among people who work in the machining fields, the term cutting is understood to refer to the macroscopic cutting operations, and grinding is mentally categorized as a separate process. This is why the terms are usually used in contradistinction in shopfloor practice, even though technically grinding is a subset of cutting.

Thread lappingRarely, thread grinding will be followed by thread lapping in order to achieve the highest precision and surface finish achievable. This is an ultradeluxe toolroom practice, rarely employed except for the leadscrews or ballscrews of highend machine tools. DIN connector is a connector that was originally standardized by the Deutsches Institut für Normung DIN, the German national standards organization. There are DIN standards for a large number of different connectors, therefore the term DIN connector alone does not unambiguously identify any particular type of connector unless the document number of the relevant DIN standard is added e.g., DIN connector. In the context of consumer electronics, the term DIN connector commonly refers to a member of a family of circular connectors that were initially standardized by DIN for analog audio signals. Some of these connectors have later also been used in analog video applications and for digital interfaces such as MIDI or the IBM PS computer keyboard and mouse cables. The original DIN standards for these connectors are no longer in print and have been replaced with the equivalent international standard IEC .While DIN connectors are superficially similar to the newer professional XLR connectors, they are not compatible.l male connectors plugs of this family of connectors feature a . mm diameter metal shield with a notch that limits the orientation in which plug and socket can mate. A range of connectors of the same form that differ only in their pin configuration exist and have been standardized originally in DIN and pin, DIN pin at °, DIN pin, DIN pin, and other standards for a range of different applications.The plugs consist of a circular shielding metal skirt protecting a number of straight round pins. The skirt is keyed to ensure that the plug is inserted with the correct orientation and to prevent damage to the pins. The basic design also ensures that the shielding is connected between socket and plug prior to any signal path connection being made.There are seven common patterns, with any number of pins from three to eight. Three different fivepin connectors exist, known as °, °, and ° after the angle of the arc swept between the first and last pin see figures above. There are also two variations of the sevenpin and eightpin connectors, one where the outer pins form ° and one where they form ° . There is some limited compatibility, for example a threepin connector will fit any ° fivepin socket, engaging three of the pins and leaving the other two unconnected, but a fivepin connector will fit some but not all threepin sockets. As well, a ° pin plug will fit into a pin or pin socket.edit Loudspeaker connectorSpeaker DIN line socket left and plug rightSpeaker DIN line socket left and plug rightA polarised twopin unshielded connector, designed for connecting a loudspeaker to a power amplifier or other device many of the earlier shoebox style tape recorders used them, is known as the DIN loudspeaker connector. It exists as a panelmounting female version, and linemounted male and female versions. The male version has a central flat pin, and circular pin mounted offcentre. It is now mainly found on older equipment, such as mm movie projectors. The Becker radio used in many MercedesBenz automobiles uses this connector. The same connector is used on some halogen lamps to connect the bulb to the power supply. While all other versions of the DIN plug are generally very reliable, the twopin DIN plug is considered inferior in some ways the lack of the outer sheath means far less force is required to disconnect the plug accidentally, makes it more prone to bending or shifting of the pins during use, and also not as solidly seated in its socket worn twopin speaker plugs on audio equipment are notorious for being very unreliable, often requiring only the slightest nudge to break contact. There are also a three and fourpin versio of this loudspeaker connector used by for example Bang & Olufsen.edit Applicationsedit Analog audioThe ° and ° connectors were originally standardized and widely used in Germany, Czech republic, and, later, in USSR and Comecon countries for interconnecting analog audio equipment, for example a stereo tape recorder to a stereo amplifier or preamplifier, using the five pins for the four signal connections plus ground. The cord used for this has a connector on each end, and the pins are connected pin for pin, that is, pin to pin , to , etc. Pins, as well as holes, are numbered from the right to the left ––––. A fourchannel cord wired in this way is sometimes simply called a DIN cord. For mono interconnections, the ° plugs are sufficient. When a mono plug is inserted into a stereo socket, it mates with the left channel. This interface was rare in the U.S. market, and has progressively disappeared on new equipment, both in Germany and worldwide, since the s, in favour of RCA connectors.

Mini-DIN connector

The mini-DIN connectors are a family of multi-pin electrical connectors used in a variety of applications. Mini-DIN is similar to the larger, older DIN connector. Both are standards of the Deutsches Institut für Normung, the German standards body.tandard connectorsMini-DIN connectors are 9.5 mm in diameter and come in seven patterns, with the number of pins from three to nine. Each pattern is keyed in such a way that a plug with one pattern cannot be mated with any socket of another pattern. An important aspect of why each of these 7 mini-DIN connectors are official standards is because they are each drastically different from the other, with no simultaneously and directly overlapping similarities in pin arrangement, square key size and position, 3 circular shielding metal skirt notches & metallic additions - unlike the nonstandard mini-DIN connectors which may have directly overlapping characteristics to each other or to the standard mini-DIN connectors.Several non-standard sockets are designed to mate with standard mini-DIN plugs. These connectors provide extra conductors, and are used to save space by combining functions in one connector that would otherwise require two standard connectors.Other non-standard connectors mate only with their matching connectors, and are mini-DIN connectors only in the sense of sharing the 9.5mm plug body. These mini-DIN style plugs are not approved by the Deutsches Institut für Normung, the German standards body, and many applications could be considered proprietary.Many laptops and video cards use a 7-pin video output jack compatible with a standard 4-pin mini-DIN plug. Pins -4 use the standard S-video pinout, enabling standard S-video cables to connect directly. A wider key prevents insertion of the matching plug into a standard 4-pin socket.The use of the extra three pins varies from manufacturer to manufacturer, but commonly includes a composite video output which is available using the manufacturers proprietary adapter. Alternatively a YPbPr signal may be provided. Later Dell laptops provide an SPDIF audio signal. Some proprietary adapters bridge specific pins in order to enable the signal on other pins, or to specify the type of signal to be delivered.The keying and pin arrangement prevents the use of the standard 7-pin mini-DIN plug, but even if a suitable plug can be obtained, use of non-proprietary adaptors on these ports may cause problems. Some graphics hardware, for example, is not engineered to have both the S-video and composite video outputs in use at once, and attempts to do this using non-standard adapters will produce poor results at best, and possible damage to the video output circuitry.Some versions of the VIVO port on some ATI and Nvidia GeForce video cards used a 9-pin connector without the small metal bar to determine how the plug fit into the socket instead, the 3 indentions in the outer ring were used. See this link 4-connector version as well as this link 6-connector version for pinout mapping, and here for the ATI Radeon VIVO port pinout mapping. * 9-pin Apple GeoPort connectorThe Apple GeoPort used a 9-pin jack compatible with either an 8-pin or a 9-pin mini-DIN plug, and was able to be used with devices designed for either the 8-pin mini-DIN Macintosh serial port connector, or the additional GeoPort protocols.Apple pin numbering follows the 8-pin DIN assignments, for compatibility with earlier Macintosh serial ports using the standard 8-pin connector. The additional pin is numbered 9 by Apple, and corresponds to pin 5 of a 9-pin mini-DIN plug. It is used for a 5V 350mA power supply available to the peripheral. Pins 5-8 of the GeoPort socket and the mini-DIN-8 plugs used with it then correspond to pins 6-9 respectively of the standard mini-DIN-9 plug.

An adapter or adaptor both spellings in use in UK and US English is a device used to match the physical or electrical characteristics of two different things so that a connection may be made between them.An adapter may be very simple, connecting one kind of plug to another kind of socket, but not changing what passes through. One example would be a garden hose, which normally has threads that screw on, but can be attached to an adapter which allows it to snap easily on and off of faucets, other hoses, or attachments. Likewise, a serial port may require an adapter to connect between the old DB-5 type and the later DE-9 type, which have 5 and 9 pins respectively but only 9 wires each.Other adapters may include a device that changes what is passing through, such as a transformer that adapts household electrical current from high voltage 00 to 40 volts AC to low voltage suitable for consumer electronics.Wire-Nut is a registered trademark of Ideal Industries for a product technically known as a twist-on wire connector. These connectors are used to fasten two or more electrical conductors together. Twist-on wire connectors are also known as a cone or thimble connectors. Marrette or Marr connector are two other trade names for such connectors. In the UK, they were made out of ceramic and sold under the brand Scru-it.Twist-on wire connectors are available in a variety of sizes and shapes and are typically made from plastic, with a tapered, conducting metal coiled insert that threads onto the wires to hold the wires secure. Cheaper varieties often didnt include the metal coil, relying instead on molded plastic threads.Twist-on wire connectors are commonly colour-coded to indicate the nuts size and hence, its wire capacity. They are commonly used as an alternative to terminal blocks or soldering conductors together because they are cleaner, faster, and allow subsequent removal for future rework.In the past, twist-on wire connectors were occasionally made of ceramic with molded threads and no internal metal coil. In many areas, this style of twist-on wire connector is no longer approved by the regulatory authorities for ordinary use, however, they may still be required in certain specific high temperature conditions.Wire nuts are widely used in America, but have not been permitted on 40v mains installations since the 950s in Britain.citation needed They are not recommended for use with aluminum wire.edit A variation on the twist-on wire connectorA new variation has, unlike ordinary twist-on wire connectors, a portion that threads onto the wires by means of a metal spring enclosed within a rigid steel canister. The spring develops very large forces on the contained wires, cutting into the wires and providing a more-secure connection. The metal can is insulated by means of a resilient plastic over-cover which is provided with two wings to allow easier turning by hand. Like ordinary twist-on wire connectors, these connectors come in several colors indicating their size with yellow being the smallest, then red, grey, and blue.Unlike conventional twist-on wire connectors, these connectors permit but do not require that the joined wires be pre-twisted before installation of the connector.Older versions of these connectors could only be used once they twisted on but the spring action did not allow them to be twisted off again without the user first crimping and thus destroying the connector. More-recent versions can be removed in the same fashion as ordinary twist-on wire connector simply unscrew them.
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