Fourpin

Fourpin is a term used to describe any connector, plug, or header that uses four conducting pins. It is not a single standardized product line, but rather a category that covers a range of form factors and applications in electronics, computing, and audio equipment. The four-pin configuration is common because it can carry multiple power and signal lines in a compact rectangular or circular housing.

In computing and electronics, several widely recognized four-pin connectors are encountered. The four-pin Molex peripheral power connector (often called a 4-pin Molex) provided auxiliary power to older hard drives, optical drives, and other components in personal computers. Another well-known example is the ATX12V four-pin CPU power connector, used to supply 12-volt power to some processors; newer systems may use newer rows or additional pins, but the four-pin variant remains common in compatibility contexts. Four-pin fan connectors are also prevalent on motherboards, where the pins support power, a tachometer signal, and a PWM control signal for speed regulation.

The term also appears in connector families such as four-pin DIN and four-pin mini-DIN, which were used in older audio equipment and video devices. These four-pin configurations come in different layouts and pin assignments depending on the standard, so compatibility depends on matching the connector type and pinout.

Overall, fourpin denotes a family of four-pin interfaces rather than a single device, covering power, control, and signaling applications across various technologies.