|Sunday, 12 November 2006|
DIP switches are small rectangular electronic components, usually packaged in a plastic housing having typical dimensions. The housing contains the electrical and mechanical components of the switch and a means to connect and solder the package to a mounting surface, described later. DIP switches comprise a plurality of single-pole, single-throw switching mechanisms physically located in a unitary package. Two parallel rows of terminals, or terminal pins, connect switching mechanisms inside the package to circuits on a printed circuit board. Each switching mechanism makes or breaks a circuit between a pair of terminals constituted by a corresponding terminal in each row. A DIP switching mechanism comprises at least one stationary contact inside the switch package. Usually this contact is formed integrally with a first terminal. A movable contact inside the package may be constructed integrally with the second terminal. It may also be independent and engage a second stationary contact that is integral with the second terminal. An actuating mechanism is accessible to an operator and shifts the movable contact to make or break a conductive path between the corresponding terminals. The top-actuated actuating mechanisms do not permit actuation of the switches from the sides. Thus, they can only be actuated if the printed circuit board to which they are electrically connected is accessible for top actuation or the board removed to actuate them. No side actuation of these switches can be performed. There are many different kinds of DIP switches which include SPST (single-pole, single-throw), MPST (multiple-pole, single-throw), MTSP (multiple-throw, single-pole), rotary contacting, and variations of all these. A DIP switch housing can contain one or more individual switches of the above types. The SPST DIP switch contains one or more SPST switches in a single package. DIP switches have a plurality of outwardly extending actuators which can be moved in the "on" or "off" position depending on the requirements of a particular application. These actuators are normally numbered, and the product that uses DIP switches comes with instructions as to the positions of the actuators. Each switch has an on and off setting which is independent of the other switches in the DIP package. Some DIP switches have different arrangements of switch contacts which can cause the switch to operate several contacts or poles with a single throw or to allow multiple positioning of a single pole. Rotary contacting DIP switches use multiple electrical switch contacts to provide a selection of switching combinations in a single package. The DIP switches can either be installed and soldered directly to the printed circuit board or the switch can be inserted within a DIP socket.
DIP switches are widely used in the area of electronics for configuring defaults on computer boards, selecting baud rate on modems, setting default for video cards, configuring pin-outs on cables, and other applications. Electronic engineers commonly provide DIP switches for use in electronic circuits to provide a way to select various system configuration choices. DIP switches are particularly used in applications having to do with computers or microprocessor-based equipment and systems. DIP switches are frequently used in computer systems to assign an address on the computer system's bus to an I/O, memory, or other option board. Address assignment refers to a function which occurs in most computer and microprocessor systems which allows the CPU (central processing unit) to select a device within the computer system with which it will transfer and receive data. In industrial applications, commands to machines controlled by a central processing unit require each machine to be assigned a unique address by, for example, common dual in-line package (DIP) switches. The central processing unit is then programmed to signal each machine by including its unique address attached to a command for that machine. DIP switches are also used to select a security code in garage-door openers, wireless telephones, and similar devices. The DIP switch provides a simple way for a user to change a value or select a number associated with the operation of that product. These products are typically based on a microprocessor and presently require several additional components to read the DIP switches' setting and adjust its operation accordingly.