A pogo pin or spring-loaded pin is a type of electrical connector mechanism that is used in many modern electronic applications and in the electronics testing industry. [1] They are used for their improved durability over other electrical contacts, and the resilience of their electrical connection to mechanical shock and vibration. [2]
The name pogo pin comes from the pin's resemblance to a pogo stick –the integrated helical spring in the pin applies a constant normal force against the back of the mating receptacle or contact plate, counteracting any unwanted movement which might otherwise cause an intermittent connection. This helical spring makes pogo pins unique, since most other types of pin mechanisms use a cantilever spring or expansion sleeve. [3]
A complete connection path requires a mating receptacle for the pin to engage, which is termed a target or land. A pogo target consists of a flat or concave metal surface, which unlike the pins, has no moving parts. Targets may be separate components in the complete connector assembly, or in the case of printed circuit boards, simply a plated area of the board.
Spring-loaded pins are precision parts fabricated with a turning and spinning process which does not require a mold, thus allowing the production of smaller quantities at a lower cost.
A basic spring-loaded pin consists of 3 main parts: a plunger, barrel, and spring. [2] When force is applied to the pin, the spring is compressed and the plunger moves inside the barrel. The shape of the barrel retains the plunger, stopping the spring from pushing it out when the pin is not locked in place.
In the design of electrical contacts, a certain amount of friction is required to hold a connector in place and retain the contact finish. However, high friction is undesirable because it increases stress and wear on the contact springs and housings. Thus, a precise normal force, typically around 1 newton, is required to generate this friction. [3] Since a spring-loaded pin needs to have a slight gap between the plunger and barrel so that it can slide easily, momentary disconnections can happen when there is vibration or movement. In order to counter this, the plunger usually has a small tilt to ensure a continuous connection.[ citation needed ]
Many manufacturers have created their own proprietary variations on this design, most commonly by varying the interface between the plunger and spring. For example, a ball may be added between the two components, or the plunger may have an angled or countersunk tip. [4]
The plunger and barrel of pogo pins usually use brass or copper as a base material on which a thin layer of nickel is applied.
As common in electrical connectors, manufacturers often apply a gold plating that improves the durability and contact resistance. [5]
The springs are usually made of copper alloys or spring steel.
Spring-loaded connectors are used for a wide variety of applications, in both industrial and consumer electronics:
When pogo pins are used in a connector, they are usually arranged in a dense array, connecting many individual nodes of two electrical circuits. They are commonly found in automatic test equipment like bed of nails testers, where they facilitate the rapid, reliable connection of the devices under test (DUTs). In one extremely high-density configuration, the array takes the form of a ring containing hundreds or thousands of individual pogo pins; this device is sometimes referred to as a pogo tower.[ citation needed ]
They can also be used for more permanent connections, for example, in the Cray-2 supercomputer. [6]
When used in the highest-performance applications, pogo pins must be very carefully designed to allow not only high reliability across many mating/unmating cycles but also high-fidelity transmission of the electrical signals. The pins themselves must be hard, yet plated with a substance (such as gold) that provides for reliable contact. Within the body of the pin, the plunger must make good electrical contact with the body lest the higher-resistance spring carry the signal (along with the undesirable inductance that the spring represents). The design of pogo pins to be used in matched-impedance circuits is especially challenging; to maintain the correct characteristic impedance, the pins are sometimes arranged with one signal-carrying pin surrounded by four, five, or six grounded pins.[ citation needed ]
Spring-loaded connectors may be combined with magnets to form a strong and reliable connection –a technique which has been employed extensively for consumer electronics such as 2-in-1 PCs and high-frequency data transfer. One notable example of this is Apple's MagSafe connector. [7]
Although often used as a generic name, pogo pin is a registered trademark of Everett Charles Technologies (ECT). [8]
The BNC connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. It is designed to maintain the same characteristic impedance of the cable, with 50 ohm and 75 ohm types being made. It is usually applied for video and radio frequency connections up to about 2 GHz and up to 500 volts. The connector has a twist to lock design with two lugs in the female portion of the connector engaging a slot in the shell of the male portion. The type was introduced on military radio equipment in the 1940s and has since become widely applied in radio systems, and is a common type of video connector. Similar radio-frequency connectors differ in dimensions and attachment features, and may allow for higher voltages, higher frequencies, or three-wire connections.
An RF connector is an electrical connector designed to work at radio frequencies in the multi-megahertz range. RF connectors are typically used with coaxial cables and are designed to maintain the shielding that the coaxial design offers. Better models also minimize the change in transmission line impedance at the connection in order to reduce signal reflection and power loss. As the frequency increases, transmission line effects become more important, with small impedance variations from connectors causing the signal to reflect rather than pass through. An RF connector must not allow external signals into the circuit through electromagnetic interference and capacitive pickup.
A breadboard, solderless breadboard, or protoboard is a construction base used to build semi-permanent prototypes of electronic circuits. Unlike a perfboard or stripboard, breadboards do not require soldering or destruction of tracks and are hence reusable. For this reason, breadboards are also popular with students and in technological education.
Components of an electrical circuit are electrically connected if an electric current can run between them through an electrical conductor. An electrical connector is an electromechanical device used to create an electrical connection between parts of an electrical circuit, or between different electrical circuits, thereby joining them into a larger circuit.
Zero insertion force (ZIF) is a type of IC socket or electrical connector that requires very little force for insertion. With a ZIF socket, before the IC is inserted, a lever or slider on the side of the socket is moved, pushing all the sprung contacts apart so that the IC can be inserted with very little force - generally the weight of the IC itself is sufficient and no external downward force is required. The lever is then moved back, allowing the contacts to close and grip the pins of the IC. ZIF sockets are much more expensive than standard IC sockets and also tend to take up a larger board area due to the space taken up by the lever mechanism. Typically, they are only used when there is a good reason to do so.
A phone connector is a family of cylindrically-shaped electrical connectors primarily for analog audio signals. Invented in the late 19th century for telephone switchboards, the phone connector remains in use for interfacing wired audio equipment, such as headphones, speakers, microphones, mixing consoles, and electronic musical instruments. A male connector, is mated into a female connector, though other terminology is used.
Electronic test equipment is used to create signals and capture responses from electronic devices under test (DUTs). In this way, the proper operation of the DUT can be proven or faults in the device can be traced. Use of electronic test equipment is essential to any serious work on electronics systems.
Integrated circuit packaging is the final stage of semiconductor device fabrication, in which the die is encapsulated in a supporting case that prevents physical damage and corrosion. The case, known as a "package", supports the electrical contacts which connect the device to a circuit board.
In electronics, a pinout is a cross-reference between the contacts, or pins, of an electrical connector or electronic component, and their functions. "Pinout" now supersedes the term "basing diagram" which was the standard terminology used by the manufacturers of vacuum tubes and the RMA. The RMA started its standardization in 1934, collecting and correlating tube data for registration at what was to become the EIA. The EIA now has many sectors reporting to it and sets what is known as EIA standards where all registered pinouts and registered jacks can be found.
Crimping is a method of joining two or more pieces of metal or other ductile material by deforming one or both of them to hold the other. The bend or deformity is called the crimp. Crimping tools are used to create crimps.
The UHF connector is a name for a threaded RF connector. The connector design was invented in the 1930s for use in the radio industry, and is a shielded form of the "banana plug". It is a widely used standard connector for HF transmission lines on full-sized radio equipment, with BNC connectors predominating for smaller, hand-held equipment.
A bed of nails tester is a traditional electronic test fixture used for in-circuit testing. It has numerous pins inserted into holes in an epoxy phenolic glass cloth laminated sheet (G-10) which are aligned using tooling pins to make contact with test points on a printed circuit board and are also connected to a measuring unit by wires. Named by analogy with a real-world bed of nails, these devices contain an array of small, spring-loaded pogo pins; each pogo pin makes contact with one node in the circuitry of the DUT. By pressing the DUT down against the bed of nails, reliable contact can be quickly and simultaneously made with hundreds or even thousands of individual test points within the circuitry of the DUT. The hold-down force may be provided manually or by means of a vacuum or a mechanical presser, thus pulling the DUT downwards onto the nails.
Fretting refers to wear and sometimes corrosion damage of loaded surfaces in contact while they encounter small oscillatory movements tangential to the surface. Fretting is caused by adhesion of contact surface asperities, which are subsequently broken again by the small movement. This breaking causes wear debris to be formed.
A Molex connector is a two-piece pin-and-socket interconnection which became an early electronic standard. Developed by Molex Connector Company in the late 1950s, the design features cylindrical spring-metal pins that fit into cylindrical spring-metal sockets, both held in a rectangular matrix in a nylon shell.
A solenoid voltmeter is a specific type of voltmeter electricians use to test electrical power circuits. It uses a solenoid coil to attract a spring-loaded plunger; the movement of the plunger is calibrated in terms of approximate voltage. It is more rugged than a D'arsonval movement, but neither as sensitive nor as precise.
A test probe is a physical device used to connect electronic test equipment to a device under test (DUT). Test probes range from very simple, robust devices to complex probes that are sophisticated, expensive, and fragile. Specific types include test prods, oscilloscope probes and current probes. A test probe is often supplied as a test lead, which includes the probe, cable and terminating connector.
NEMA connectors are power plugs and receptacles used for AC mains electricity in North America and other countries that use the standards set by the US National Electrical Manufacturers Association. NEMA wiring devices are made in current ratings from 15 to 60 amperes (A), with voltage ratings from 125 to 600 volts (V). Different combinations of contact blade widths, shapes, orientations, and dimensions create non-interchangeable connectors that are unique for each combination of voltage, electric current carrying capacity, and grounding system.
A Fuzz Button is a high performance electrical connection material used to connect two parts of an electrical circuit together, for example an IC to a PCB or two PCBs to each other. Fuzz Buttons consist of a single strand of gold-plated beryllium copper wire compressed into a dense, sponge-like cylindrical shape. Their diameter can range from a few tenths of a millimetre to a millimetre.
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Gold is generally specified as a contact coating for low level signal voltage and current applications, and where high reliability is a major consideration
Pogo is a registered trademark of Everett Charles Technologies