![RockerDipSwitch](https://upload.wikimedia.org/wikipedia/commons/8/8b/RockerDipSwitch.png)
A DIP switch is a manual
electric switch
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type ...
that is packaged with others in a group in a standard
dual in-line package (DIP). The term may refer to each individual switch, or to the unit as a whole. This type of switch is designed to be used on a
printed circuit board along with other
electronic
Electronic may refer to:
*Electronics, the science of how to control electric energy in semiconductor
* ''Electronics'' (magazine), a defunct American trade journal
*Electronic storage, the storage of data using an electronic device
*Electronic co ...
components and is commonly used to customize the behavior of an electronic device for specific situations.
DIP switches are an alternative to
jumper blocks. Their main advantages are that they are quicker to change and there are no parts to lose.
History
![Sab Rotary Switch](https://upload.wikimedia.org/wikipedia/commons/d/d7/Sab_Rotary_Switch.jpg)
US patent 3,621,157 is the earliest known DIP switch patent. The patent discloses a rotary style DIP switch invented by Pierre P. Schwab. Schwab's patent application was filed on June 1, 1970, and the patent was granted on November 16, 1971.
The DIP switch with sliding levers was granted US patent 4012608 in 1976. It was applied for 1974 and was used in 1977 in an
ATARI Flipper game.
Types
![Sab 2PST DIP Switch](https://upload.wikimedia.org/wikipedia/commons/4/43/Sab_2PST_DIP_Switch.jpg)
The slide, rocker, and piano types, which are very common, are arrays of simple
single pole, single throw (SPST) contacts, each of which can be either on or off. This allows each switch to select a one-bit binary value. The values of all switches in the package can also be interpreted as one number. For example, seven switches offer 128 (2
7) combinations, allowing them to select a standard ASCII character. Eight switches offer 256 (2
8) combinations, which is equivalent to one
byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable uni ...
.
A tri-state type DIP switch can be in one of three positions (+, 0, -) which allows more codes than a binary DIP switch. For example, 8 pole tri-state DIP switches offer 6,561 (3
8) combinations/codes compared to 8 pole binary switches' 256 (2
8) combinations/codes. This makes them especially suitable for encoding devices such as a remote controller.
Rotary DIP switches contain multiple
electrical contact
An electrical contact is an electrical circuit component found in electrical switches, relays, connectors and circuit breakers. Each contact is a piece of electrically conductive material, typically metal. When a pair of contacts touch, they c ...
s, one of which is selected by rotating the switch to align it with a number printed on the package. Some have a knob that can be turned by fingers, or a small slot that requires a
screwdriver
A screwdriver is a tool, manual or powered, used for turning screws. A typical simple screwdriver has a handle and a shaft, ending in a tip the user puts into the screw head before turning the handle. This form of the screwdriver has been repla ...
to change them. Typically, rotary types are available in two different types of output, 1) a binary encoded output, where 10 (BCD) or 16 (hex) choices are encoded into a 4-bit binary output, or 5 to 8 choices are encoded into a 3-bit binary output. 2) a rotary version of a multipole slide switch where one signal has a choice between multiple connections, such as SPDT, SP3T, SP4T.
The DIP switch package also has socket pins or mounting leads to provide an electrical path from the switch contacts to the circuit board. Although circuits can use the electrical contacts directly, it is more common to convert them into high and low signals. In this case, the circuit board also needs interface circuitry for the DIP switch, consisting of a series of pull-up or pull-down resistors, a buffer, decode logic, and other components. Typically, the device's
firmware reads the DIP switches when the device is powered on.
With the popularization of
surface-mount technology, these switches are now commonly available in non-DIP surface-mount package types. They are, however, still referred to as "DIP switches", as the term has become associated with the style of switch.
Contacts
![Sab Tri state type DIP switch](https://upload.wikimedia.org/wikipedia/commons/a/a2/Sab_Tri_state_type_DIP_switch.jpg)
There are many different kinds of DIP switches. Some of the most common are the slide, rocker, piano (side), and rotary types.
Slide / rocker / piano DIP switches are commonly available in 1 to 12 contacts (positions)
SPST, though some are available as special order up to 30 contacts (positions).
Applications
![Miniature Rotary coded switch](https://upload.wikimedia.org/wikipedia/commons/3/37/Miniature_Rotary_coded_switch.jpg)
DIP switches were used extensively in
ISA architecture of PC
expansion card
In computing, an expansion card (also called an expansion board, adapter card, peripheral card or accessory card) is a printed circuit board that can be inserted into an electrical connector, or expansion slot (also referred to as a bus sl ...
s to select
IRQs and
memory address
In computing, a memory address is a reference to a specific memory location used at various levels by software and hardware. Memory addresses are fixed-length sequences of digits conventionally displayed and manipulated as unsigned integers. ...
es. Before the advent of cheaper, battery-backed RAM, DIP switches were also often used on
arcade games in the 1980s and early 1990s to enter game settings such as difficulty or the number of credits per coin. DIP switches were very commonly used to set security codes on
garage door openers as well as on some early
cordless phone
A cordless telephone or portable telephone has a portable telephone handset that connects by radio to a base station connected to the public telephone network. The operational range is limited, usually to the same building or within some short ...
s. This design, which used up to 12 switches in a group, was used to avoid
RF interference
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrost ...
from other nearby door opener remotes or other devices. Current garage door openers use
rolling code
A rolling code (or sometimes called a hopping code) is used in keyless entry systems to prevent replay attacks, where an eavesdropper records the transmission and replays it at a later time to cause the receiver to 'unlock'. Such systems are typi ...
systems for better security.
These types of switches were used on early
video card
A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer mo ...
s for early computers to facilitate compatibility with other video standards. For example,
CGA cards allowed for
MDA compatibility.
After the late 1990s, DIP switches became less common in
consumer electronics
Consumer electronics or home electronics are electronic ( analog or digital) equipment intended for everyday use, typically in private homes. Consumer electronics include devices used for entertainment, communications and recreation. Usuall ...
. Reasons include the trend toward smaller products, the demand for easier configuration through
software
Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work.
...
menu
In a restaurant, the menu is a list of food and beverages offered to customers and the prices. A menu may be à la carte – which presents a list of options from which customers choose – or table d'hôte, in which case a pre-established seque ...
s or
plug and play
In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving resou ...
, and the falling price of
non-volatile memory
Non-volatile memory (NVM) or non-volatile storage is a type of computer memory that can retain stored information even after power is removed. In contrast, volatile memory needs constant power in order to retain data.
Non-volatile memory typi ...
. However, DIP switches are still widely used in industrial equipment because they are inexpensive and easy to incorporate into circuit designs, and because they allow settings to be checked at a glance without powering the system on.
DIP switches are still used in some
remote control
In electronics, a remote control (also known as a remote or clicker) is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such a ...
s to prevent interference; for example, to control a
ceiling fan
A ceiling fan is a mechanical fan, fan mounted on the ceiling of a room or space, usually electric power, electrically powered, that uses hub-mounted rotation, rotating blades to wikt:circulation, circulate air. They cool people effectively by ...
(and its
light fixture
A light fixture (US English), light fitting (UK English), or luminaire is an electrical device containing an electric lamp that provides illumination. All light fixtures have a fixture body and one or more lamps. The lamps may be in sockets for ...
) that was
retrofit
Retrofitting is the addition of new technology or features to older systems. Retrofits can happen for a number of reasons, for example with big capital expenditures like naval vessels, military equipment or manufacturing plants, businesses or go ...
ted to a single-
circuit junction box
An electrical junction box (also known as a "jbox") is an enclosure housing electrical connections. Junction boxes protect the electrical connections from the weather, as well as protecting people from accidental electric shocks.
Construction ...
. The DIP switches set a different
radio frequency
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage or of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around to around . This is roughly between the ...
or address for each
transmitter
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to the ...
/
receiver pair, so that multiple units can be installed without unintentionally controlling each other.
References
External links
DIP Switches(5MB PDF) - C&K Switches
ArchiveDIP Switches(1MB PDF) - CTS
ArchiveDIP Switches- Grayhill
ArchiveDIP Switches(33MB PDF) - TE Connectivity
ArchiveDIP Switches(7MB PDF) - Sab Switches
Archive
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Switches
fr:Interrupteur#DIP switch