Instrument and Computer Power Connectors

Instrument power connectors and computer (disk drive) power connectors are used to connect a computer’s power supply to a hard disk, floppy disk, compact disk (CD), digital video disk (DVD), or other type of disk drive. They are also used with removable media drives such as Zip disks, and computer cooling devices such as fans and electro-thermal coolers. Instrument power connectors and computer (disk drive) power connectors consist of a plastic housing and four wires that provide +5V and +12V power, along with two grounds, to each disk drive. There are two basic types of products: Molex and mini-plug. Molex connectors are keyed devices that attach to disk drives by friction. They are larger than mini-plug connectors and often use American Wire Gauge (AWG) 16 to 18 wires. Mini-plug connectors are designed to fit into a retention clip on the disk drive. Products that are used with floppies and other disc drives that draw little current use AWG 18 to AWG 22 wire. Selecting instrument power connectors and computer power connectors requires an analysis of product features. Current, voltage, operating temperature, housing material, contact material, and plating are important parameters to consider. Current is measured in amperes (e.g., 10.0A, 18.0A, etc.) Voltage is measured in volts (e.g., 250V, 1000V). Operating temperature is specified as a range and measured in degrees Fahrenheit (F) or degrees Celsius (C). Housing materials for instrument power connectors and computer (disk drive) power connectors include nylon, glass-filled nylon, natural thermoplastic, and high-temperature thermoplastic. Electrical contacts are made of metallic elements and alloys such as copper, brass, or phosphorous bronze. Tin and tin over nickel are common plating materials. Maximum printed circuit board (PCB) thickness, receptacle type, Molex number, and number of contact points are additional product specifications to consider. Instrument power connectors and computer power connectors differ in terms of features and approvals. Some products feature polarized housings, fully-isolated terminals, anti-wicking tails, or anti-tangle latches. Others are designed specifically for PCBs that use surface mount technology (SMT) or through-hole technology (THT). Specialized disk drive power connectors may be specified as receptacles, plugs, terminals, vertical headers, high-temperature vertical headers, or female crimp housings. In terms of approvals, instrument power connectors and computer power connectors that are destined for sale in Europe should meet the Restriction of Hazardous Substances (RoHS) and the Waste Electrical and Electronics Equipment (WEEE) directives from the European Union (EU).