DIN 41612 was a DIN standard for electrical connectors that are widely used in rack based electrical systems. Standardisation of the connectors is a pre-requisite for open systems, where users expect components from different suppliers to operate together. The most widely known use of DIN 41612 connectors is in the VMEbus and NuBus systems. The standard has withdrawn in favor of international standards IEC 60603-2 and EN 60603-2. DIN 41612 connectors are used in Pancon, STEbus, Futurebus, VMEbus, Multibus II, NuBus, VXI Bus, eurocard TRAM motherboards, and Europe Card Bus, all of which typically use male DIN 41612 connectors on Eurocards plugged into female DIN 41612 on the backplane in a 19-inch rack chassis. The standard describes connectors which may have one, two or three rows of contacts, which are labelled as rows a, b and c. Two row connectors may use rows a+b or rows a+c. The connectors may have 16 or 32 columns, which means that the possible permutations allow 16, 32, 48, 64 or 96 contacts. The rows and columns are on a 0.1 inch (2.54 mm) grid pitch. Insertion and removal force are controlled, and three durability grades are available. Often the female DIN 41612 connectors have press fit contacts rather than solder pin contacts, to avoid thermal shock to the backplane. A battery holder is one or more compartments or chambers for holding a battery. For dry cells, the holder must also make electrical contact with the battery terminals. For wet cells, cables are often connected to the battery terminals, as is found in automobiles or emergency lighting equipment. A battery holder is either a plastic case with the shape of the housing moulded as a compartment or compartments that accepts a battery or batteries, or a separate plastic holder that is mounted with screws, eyelets, glue, double-sided tape, or other means. Battery holders may have a lid to retain and protect the batteries or may be sealed to prevent damage to circuitry and components from battery leakage. Coiled spring wire or flat tabs that press against the battery terminals are the two most common methods of making the electrical connection inside a holder. External connections on battery holders are usually made by contacts with pins, surface mount feet, solder lugs, or wire leads. Where the battery is expected to last over the life of the product, no holder is necessary, and a tab welded to the battery terminals can be directly soldered to a printed circuit board. A pin header (or simply header) is a form of electrical connector. A male pin header consists of one or more rows of metal pins molded into a plastic base, often 2.54 mm (0.1 in) apart, though available in many spacings. Male pin headers are cost-effective due to their simplicity. The female counterparts are sometimes known as female socket headers, though there are numerous naming variations of male and female connectors. Historically, headers have sometimes been called "Berg connectors", but headers are manufactured by many companies. A SCSI connector is used to connect computer parts that use a system called SCSI to communicate with each other. Generally, two connectors, designated male and female, plug together to form a connection which allows two components, such as a computer and a disk drive, to communicate with each other. SCSI connectors can be electrical connectors or optical connectors. There have been a large variety of SCSI connectors in use at one time or another in the computer industry. Twenty-five years of evolution and three major revisions of the standards resulted in requirements for Parallel SCSI connectors that could handle an 8, 16 or 32 bit wide bus running at 5, 10 or 20 megatransfer/s, with conventional or differential signaling. Serial SCSI added another three transport types, each with one or more connector types. Manufacturers have frequently chosen connectors based on factors of size, cost, or convenience at the expense of compatibility. A card edge connector is the portion of a printed circuit board (PCB) consisting of traces leading to the edge of the board that are intended to plug into a matching socket. The edge connector is a money-saving device because it only requires a single discrete female connector (the male connector is formed out of the edge of the PCB), and they also tend to be fairly robust and durable. They are commonly used in computers for expansion slots for peripheral cards, such as PCI, PCI Express, and AGP cards. Terminal block is an accessory product used to realize electrical connection, which is divided into the category of connector in industry. With the increasing degree of industrial automation and the stricter and more precise requirements of industrial control, the amount of terminal blocks is gradually increasing. With the development of the electronics industry, the use of terminal blocks is increasing, and there are more and more types. In addition to PCB board terminals, the most widely used ones are hardware terminals, nut terminals, spring terminals and so on. The terminal is used to facilitate the connection of wires. It is actually a piece of metal enclosed in insulating plastic. There are holes at both ends to insert wires. There are screws for fastening or loosening, such as two wires, sometimes Need to connect, sometimes need to be disconnected, then you can use the terminal to connect them, and can be disconnected at any time, without having to solder or twist them together, very convenient and fast. And it is suitable for a large number of wire interconnections. In the power industry, there are special terminal blocks and terminal boxes, all of which are terminal blocks, single-layer, double-layer, current, voltage, common, breakable and so on. A certain crimping area is to ensure reliable contact and to ensure that enough current can pass. A circular connector is a type of connector whose basic structure is cylindrical and has a circular mating surface. In the interconnection classification, it belongs to category 5 and is used for interconnection between devices. Broadly speaking, it includes low-frequency circular connectors, RF coaxial connectors and audio connectors. The cylindrical structure of the circular connector is inherently robust and provides greater strength than any other shape. Automotive connectors are a component that electronic engineering technicians often touch. Its function is very simple: it sets up a bridge of communication between the blocked or isolated circuits in the circuit, so that the current flows and the circuit realizes the predetermined function. The form and structure of automotive connectors are ever-changing. They are mainly composed of four basic structural components, namely: contacts, shells (depending on the variety), insulators, and accessories. In the industry, it is usually also called sheath, connector, plastic shell. Board-to-board connectors are the connector products with the strongest transmission capacity among all connector product types, mainly used in power systems, communication networks, financial manufacturing, elevators, industrial automation, medical equipment, office equipment, home appliances, military manufacturing and other industries . An IC socket is an integrated circuit socket mounted on a circuit board, characterized by a plurality of electrical contacts arranged in a plurality of cavities. An integrated circuit socket includes an insulating shell, and the insulating shell has an integrated circuit package accommodating groove in which the integrated circuit package is accommodated. The contacts are embedded in cavities arranged in a matrix arrangement in the accommodating grooves of the integrated circuit package.