Protoboard circuito multivibradores.jpg
   HOME

TheInfoList



OR:

A breadboard, solderless breadboard, or protoboard is a construction base used to build semi-permanent
prototype A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...
s of
electronic circuit An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors and diodes, connected by conductive wires or traces through which electric current can flow. It is a type of electrical ...
s. Unlike a perfboard or stripboard, breadboards do not require soldering or destruction of tracks and are hence reusable. For this reason, breadboards are also popular with students and in technological education. A variety of electronic systems may be prototyped by using breadboards, from small analog and digital circuits to complete central processing units (CPUs). Compared to more permanent circuit connection methods, modern breadboards have high parasitic capacitance, relatively high resistance, and less reliable connections, which are subject to jostle and physical degradation. Signaling is limited to about 10 MHz, and not everything works properly even well below that frequency.


History

In the early days of radio, amateurs nailed bare copper wires or terminal strips to a wooden board (often literally a bread cutting board) and soldered electronic components to them. Sometimes a paper schematic diagram was first glued to the board as a guide to placing terminals, then components and wires were installed over their symbols on the schematic. Using thumbtacks or small nails as mounting posts was also common. Breadboards have evolved over time, with the term now being used for all kinds of prototype electronic devices. For example, US Patent 3,145,483, was filed in 1961 and describes a wooden plate breadboard with mounted springs and other facilities. US Patent 3,496,419, was filed in 1967 and refers to a particular
printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
layout as a ''Printed Circuit Breadboard''. Both examples refer to and describe other types of breadboards as prior art. In 1960, Orville Thompson of
DeVry Technical Institute DeVry University () is a private for-profit university with its headquarters in Naperville, Illinois. It was founded in 1931 by Herman A. DeVry and is accredited by the Higher Learning Commission. DeVry is predominantly an online educator bu ...
patented a solderless breadboard connecting rows of holes together with spring metal. In 1971, Ronald Portugal of E&L Instruments patented a similar concept with holes in spacings, the same as DIP IC packages, which became the basis of the modern solderless breadboard that is commonly used today.


Prior art

* US Patent 231708, filed in 1880, "''Electrical switch board''".U.S. Patent 231708.
"Electrical switch board", filed 31 Aug 1880, retrieved 4 August 2019.
* US Patent 2477653, filed in 1943, "''Primary electrical training test board apparatus''".U.S. Patent 2477653.
: "Primary electrical training test board apparatus", filed 10 Apr 1943, retrieved 14 July 2017.
* US Patent 2592552, filed in 1944, "''Electrical instruction board''".U.S. Patent 2592552.
"Electrical instruction board", filed 4 Oct 1944, retrieved 23 Oct 2022.
* US Patent 2568535, filed in 1945, "''Board for demonstrating electric circuits''".U.S. Patent 2568535.
: "Board for demonstrating electric circuits", filed 10 Apr 1945, retrieved 14 July 2017.
* US Patent 2885602, filed in 1955, "''Modular circuit fabrication''", National Cash Register (NCR).U.S. Patent 2885602.
"Modular circuit fabrication", filed 4 Apr 1955, retrieved 14 July 2017.
* US Patent 3062991, filed in 1958, "''Quick attaching and detaching circuit system''".U.S. Patent 3062991.
: "Quick attaching and detaching circuit system", filed 8 Sep 1958, retrieved 14 July 2017.
* US Patent 2983892, filed in 1958, "''Mounting assemblage for electrical circuits''".U.S. Patent 2983892.
: "Mounting assemblage for electrical circuits", filed 14 Nov 1958, retrieved 14 July 2017.
* US Patent 3085177, filed in 1960, "''Device for facilitating construction of electrical apparatus''",
DeVry Technical Institute DeVry University () is a private for-profit university with its headquarters in Naperville, Illinois. It was founded in 1931 by Herman A. DeVry and is accredited by the Higher Learning Commission. DeVry is predominantly an online educator bu ...
.U.S. Patent 3085177.
: "Device for facilitating construction of electrical apparatus", filed 7 Jul 1960, retrieved 14 Jan 2017.
* US Patent 3078596, filed in 1960, "''Circuit assembly board''".U.S. Patent 3078596.
: "Circuit assembly board", filed 21 Nov 1960, retrieved 14 Jan 2017.
* US Patent 3145483, filed in 1961, "''Test board for electronic circuits''".U.S. Patent 3145483.
: "Test board for electronic circuits", filed 4 May 1961, retrieved 14 July 2017.
* US Patent 3277589, filed in 1964, "''Electrical experiment kit''".U.S. Patent 3277589.
: "Electrical experiment kit", filed 5 Nov 1964, retrieved 14 July 2017.
* US Patent 3447249, filed in 1966, "''Electronic building set''".U.S. Patent 3447249.
"Electronic building set", filed 5 May 1966, retrieved 14 Jan 2017.
See
Lectron Lectron was a modular electronic experimentation kit designed to introduce youth to basic electronic circuits and theory. Description The Lectron kit consisted of electronic components installed within individual "building blocks" with a clear ...
blocks / dominoes. * US Patent 3496419, filed in 1967, "''Printed circuit breadboard''".U.S. Patent 3496419.
: "Printed circuit breadboard", filed 25 Apr 1967, retrieved 14 July 2017.
* US Patent 3540135, filed in 1968, "''Educational training aids''".U.S. Patent 3540135.
"Educational training aids", filed 11 Oct 1968, retrieved 14 July 2017.
* US Patent 3733574, filed in 1971, "''Miniature tandem spring clips''", Vector Electronics.U.S. Patent 3733574.
"Miniature tandem spring clips", filed 23 Jun 1971, retrieved 14 Jan 2017.
* US Patent D228136, filed in 1971, "''Breadboard for electronic components or the like''", E&L Instruments.U.S. Patent D228136.
"Breadboard for electronic components or the like", filed 1 Dec 1971, retrieved 14 July 2017.
This is the modern solderless breadboard.


Design

A modern solderless breadboard socket consists of a perforated block of plastic with numerous tin plated phosphor bronze or nickel silver alloy spring clips under the perforations. The clips are often called ''tie points'' or ''contact points''. The number of tie points is often given in the specification of the breadboard. The spacing between the clips (lead pitch) is typically .
Integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
s (ICs) in
dual in-line package In microelectronics, a dual in-line package (DIP or DIL), is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board (P ...
s (DIPs) can be inserted to straddle the centerline of the block. Interconnecting wires and the leads of discrete components (such as capacitors,
resistor A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active el ...
s, and inductors) can be inserted into the remaining free holes to complete the circuit. Where ICs are not used, discrete components and connecting wires may use any of the holes. Typically the spring clips are rated for 1
ampere The ampere (, ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to elect ...
at 5 volts and 0.333 amperes at 15 volts (5 watts).


Bus and terminal strips

Solderless breadboards connect pin to pin by metal strips inside the breadboard. The layout of a typical solderless breadboard is made up from two types of areas, called strips. Strips consist of interconnected electrical terminals.Often breadboard strips or blocks of one brand have male and female
dovetail A dovetail joint or simply dovetail is a joinery technique most commonly used in woodworking joinery (carpentry), including furniture, cabinets, log buildings, and traditional timber framing. Noted for its resistance to being pulled apart (ten ...
notches so boards can be clipped together to form a large breadboard. The main areas, to hold most of the electronic components, are called ''terminal strips''. In the middle of a terminal strip of a breadboard, one typically finds a notch running in parallel to the long side. The notch is to mark the centerline of the terminal strip and provides limited airflow (cooling) to DIP ICs straddling the centerline. The clips on the right and left of the notch are each connected in a radial way; typically five clips (i.e., beneath five holes) in a row on each side of the notch are electrically connected. The five columns on the left of the notch are often marked as A, B, C, D, and E, while the ones on the right are marked F, G, H, I and J. When a "skinny" dual in-line pin package (DIP) integrated circuit (such as a typical DIP-14 or DIP-16, which have a separation between the pin rows) is plugged into a breadboard, the pins of one side of the chip are supposed to go into column E while the pins of the other side go into column F on the other side of the notch. The rows are identified by numbers from 1 to as many the breadboard design goes. A full-size terminal breadboard strip typically consists of around 56 to 65 rows of connectors. Together with bus strips on each side this makes up a typical 784 to 910 tie point solderless breadboard. Most breadboards are designed to accommodate 17, 30 or 64 rows in the mini, half, and full configurations respectively. To provide power to the electronic components, ''bus strips'' are used. A bus strip usually contains two columns: one for ground and one for a supply voltage. However, some breadboards only provide a single-column power distribution bus strip on each long side. Typically the row intended for a supply voltage is marked in red, while the row for ground is marked in blue or black. Some manufacturers connect all terminals in a column. Others just connect groups of, for example, 25 consecutive terminals in a column. The latter design provides a circuit designer with some more control over
crosstalk In electronics, crosstalk is any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates an undesired effect in another circuit or channel. Crosstalk is usually caused by undesired capacitive, induc ...
(inductively coupled noise) on the power supply bus. Often the groups in a bus strip are indicated by gaps in the color marking. Bus strips typically run down one or both sides of a terminal strip or between terminal strips. On large breadboards additional bus strips can often be found on the top and bottom of terminal strips. Some manufacturers provide separate bus and terminal strips. Others just provide breadboard blocks which contain both in one block.


Jump wires

Jump wires (also called jumper wires) for solderless breadboarding can be obtained in ready-to-use jump wire sets or can be manually manufactured. The latter can become tedious work for larger circuits. Ready-to-use jump wires come in different qualities, some even with tiny plugs attached to the wire ends. Jump wire material for ready-made or homemade wires should usually be 22  AWG (0.33 mm2) solid copper, tin-plated wire - assuming no tiny plugs are to be attached to the wire ends. The wire ends should be stripped . Shorter stripped wires might result in bad contact with the board's spring clips (insulation being caught in the springs). Longer stripped wires increase the likelihood of short-circuits on the board.
Needle-nose pliers Needle-nose pliers, also known as long-nose pliers and snipe-nose pliers, are both cutting and holding pliers used by artisans, jewellery designers, electricians, network engineers and other tradesmen to bend, re-position and snip wire. Their namesa ...
and tweezers are helpful when inserting or removing wires, particularly on crowded boards. Differently colored wires and
color-coding In computer science and graph theory, the term color-coding refers to an algorithmic technique which is useful in the discovery of network motifs. For example, it can be used to detect a simple path of length in a given graph. The traditional c ...
discipline are often adhered to for consistency. However, the number of available colors is typically far fewer than the number of signal types or paths. Typically, a few wire colors are reserved for the supply voltages and ground (e.g., red, blue, black), some are reserved for main signals, and the rest are simply used where convenient. Some ready-to-use jump wire sets use the color to indicate the length of the wires, but these sets do not allow a meaningful color-coding schema.


Advanced designs

In a more robust variant, one or more breadboard strips are mounted on a sheet of metal. Typically, that backing sheet also holds a number of binding posts. These posts provide a clean way to connect an external power supply. This type of breadboard may be slightly easier to handle. Some manufacturers provide high-end versions of solderless breadboards. These are typically high-quality breadboard modules mounted on a flat casing. The casing contains additional equipment for breadboarding, such as a power supply, one or more signal generators,
serial interface In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. T ...
s, LED display or LCD modules, and
logic probe A logic probe is a low-cost hand-held test probe used for analyzing and troubleshooting the logical states (boolean 0 or 1) of a digital circuit. When many signals need to be observed or recorded simultaneously, a logic analyzer is used instead. ...
s. For high-frequency development, a metal breadboard affords a desirable solderable ground plane, often an unetched piece of printed circuit board; integrated circuits are sometimes stuck upside down to the breadboard and soldered to directly, a technique sometimes called " dead bug" construction because of its appearance. Examples of dead bug with ground plane construction are illustrated in a Linear Technologies application note. Dead-bug breadboards with ground plane, and other prototyping techniques, illustrated in Figures F1 to F24, from p. AN47-98. There is information on breadboarding on pp. AN47-26 to AN47-29.


Uses

A common use in the
system on a chip A system on a chip or system-on-chip (SoC ; pl. ''SoCs'' ) is an integrated circuit that integrates most or all components of a computer or other electronic system. These components almost always include a central processing unit (CPU), memory ...
(SoC) era is to obtain an
microcontroller A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable i ...
(MCU) on a pre-assembled
printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
(PCB) which exposes an array of input/output (IO) pins in a header suitable to plug into a breadboard, and then to prototype a circuit which exploits one or more of the MCU's peripherals, such as general-purpose input/output (GPIO), UART/ USART serial transceivers, analog-to-digital converter (ADC), digital-to-analog converter (DAC),
pulse-width modulation Pulse-width modulation (PWM), or pulse-duration modulation (PDM), is a method of reducing the average power delivered by an electrical signal, by effectively chopping it up into discrete parts. The average value of voltage (and current) fed ...
(PWM; used in
motor control Motor control is the regulation of movement in organisms that possess a nervous system. Motor control includes reflexes as well as directed movement. To control movement, the nervous system must integrate multimodal sensory information (both f ...
), Serial Peripheral Interface (SPI), or I²C.
Firmware In computing, firmware is a specific class of computer software that provides the low-level control for a device's specific hardware. Firmware, such as the BIOS of a personal computer, may contain basic functions of a device, and may provide h ...
is then developed for the MCU to test, debug, and interact with the circuit prototype. High frequency operation is then largely confined to the SoC's PCB. In the case of high speed interconnects such as SPI and I²C, these can be debugged at a lower speed and later rewired using a different circuit assembly methodology to exploit full-speed operation. A single small SoC often provides most of these electrical interface options in a form factor barely larger than a large postage stamp, available in the American hobby market (and elsewhere) for a few dollars, allowing fairly sophisticated breadboard projects to be created at modest expense.


Limitations

Complex circuit built around a microprocessor Prototype microphone preamp built with SMD components soldered to SIP- or DIL adapter boards Due to relatively large
parasitic capacitance Parasitic capacitance is an unavoidable and usually unwanted capacitance that exists between the parts of an electronic component or circuit simply because of their proximity to each other. When two electrical conductors at different voltages a ...
compared to a properly laid out PCB (approx 2 pF between adjacent contact columns), high
inductance Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the ...
of some connections and a relatively high and not very reproducible contact
resistance Resistance may refer to: Arts, entertainment, and media Comics * Either of two similarly named but otherwise unrelated comic book series, both published by Wildstorm: ** ''Resistance'' (comics), based on the video game of the same title ** ''T ...
, solderless breadboards are limited to operation at relatively low frequencies, usually less than 10  MHz, depending on the nature of the circuit. The relatively high contact resistance can already be a problem for some DC and very low frequency circuits. Solderless breadboards are further limited by their voltage and current ratings. Solderless breadboards usually cannot accommodate
surface-mount technology Surface-mount technology (SMT), originally called planar mounting, is a method in which the electrical components are mounted directly onto the surface of a printed circuit board (PCB). An electrical component mounted in this manner is referred ...
devices (SMD) or components with grid spacing other than . Further, they cannot accommodate components with multiple rows of connectors if these connectors do not match the dual in-line layout—it is impossible to provide the correct electrical connectivity. Sometimes small
PCB PCB may refer to: Science and technology * Polychlorinated biphenyl, an organic chlorine compound, now recognized as an environmental toxin and classified as a persistent organic pollutant * Printed circuit board, a board used in electronics * ...
adapters called "breakout adapters" can be used to fit the component to the board. Such adapters carry one or more components and have spaced male connector pins in a single in-line or dual in-line layout, for insertion into a solderless breadboard. Larger components are usually plugged into a socket on the adapter, while smaller components (e.g., SMD resistors) are usually soldered directly onto the adapter. The adapter is then plugged into the breadboard via the connectors. However, the need to solder the components onto the adapter negates some of the advantage of using a solderless breadboard. Very complex circuits can become unmanageable on a solderless breadboard due to the large amount of wiring required. The very convenience of easy plugging and unplugging of connections also makes it too easy to accidentally disturb a connection, and the system becomes unreliable. It is possible to prototype systems with thousands of connecting points, but great care must be taken in careful assembly, and such a system becomes unreliable as contact resistance develops over time. At some point, very complex systems must be implemented in a more reliable interconnection technology, to have a likelihood of working over a usable time period.


Alternatives

Alternative methods to create prototypes are point-to-point construction (reminiscent of the original wooden breadboards),
wire wrap Wire wrap is an electronic component assembly technique that was invented to wire telephone crossbar switches, and later adapted to construct electronic circuit boards. Electronic components mounted on an insulating board are interconnected by l ...
,
wiring pencil A wiring pencil (often sold under the trade names of Roadrunner or Verowire) is a tool for making electrical connections. A small reel of insulated copper wire is mounted at the top of the tool. The wire runs down the center of the wiring pencil ...
, and boards like the stripboard. Complicated systems, such as modern computers comprising millions of transistors,
diode A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other. A diode ...
s, and
resistor A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active el ...
s, do not lend themselves to prototyping using breadboards, as their complex designs can be difficult to lay out and
debug In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve int ...
on a breadboard. Modern circuit designs are generally developed using a schematic capture and simulation system, and tested in software simulation before the first prototype circuits are built on a
printed circuit board A printed circuit board (PCB; also printed wiring board or PWB) is a medium used in Electrical engineering, electrical and electronic engineering to connect electronic components to one another in a controlled manner. It takes the form of a L ...
.
Integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
designs are a more extreme version of the same process: since producing prototype silicon is costly, extensive software simulations are performed before fabricating the first prototypes. However, prototyping techniques are still used for some applications such as RF circuits, or where software models of components are inexact or incomplete. It is also possible to use a square grid of pairs of holes where one hole per pair connects to its row and the other connects to its column. This same shape can be in a circle with rows and columns each spiraling opposite clockwise/counterclockwise.


See also

*
Brassboard A brassboard or brass board is an experimental or demonstration test model, intended for field testing outside the laboratory environment. A brassboard follows an earlier prototyping stage called a breadboard. A brassboard contains both the function ...
* DIN rail * Expansion spring *
Fahnestock clip A Fahnestock clip is an early type of spring clamp electrical terminal for connections to bare wires. It is still used in educational electronic kits and teaching laboratories in schools. It is designed to grip a bare wire securely, yet releas ...
* Iterative design * Optical table


References


External links


Large parallel processing design prototyped on 50 connected breadboards
{{Authority control Electronic design Electronics substrates Electronic test equipment Electronics work tools