 Manual wire wrapping/stripping tool and wire in various colours.
 Electrical wire wrap tool.
 Manual tool to open a wire wrap connection. Wire wrap is a technique for constructing small numbers of complex electronics assemblies. It is an alternative technique to the use of small runs of printed circuit boards, and has the advantage of being easily changed for prototyping work. It has been used to construct telephone exchanges, computers, control consoles, radios, radars, sonars, and other complex pieces of equipment that are needed in small volumes; the Apollo Guidance Computer, among many other historically relevant computers, was constructed using wire wrap technology. Image File history File links Download high-resolution version (1446x560, 111 KB) This photo shows a manual wire wrap tool and wire wrap wire in various colours. ...
Image File history File links Download high-resolution version (1446x560, 111 KB) This photo shows a manual wire wrap tool and wire wrap wire in various colours. ...
Image File history File links Download high-resolution version (1456x846, 558 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Wire wrap ...
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The field of electronics comprises the study and use of systems that operate by controlling the flow of electrons (or other charge carriers) in devices such as thermionic valves (vacuum tubes) and semiconductors. ...
Close-up photo of one side of a motherboard PCB, showing conductive traces, vias and solder points for through-hole components on the opposite side. ...
It has been suggested that Prototype be merged into this article or section. ...
A Verizon Central Office in Lakeland, Florida at night. ...
A BlueGene supercomputer cabinet. ...
This long range RADAR antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll[1]. RADAR is a system that uses radio waves to determine and map the location, direction, and/or speed...
The F70 type frigates (here, La Motte-Picquet) are fitted with VDS (Variable Depth Sonar) type DUBV43 or DUBV43C tugged sonars SONAR (SOund Navigation And Ranging) — or sonar — (the British used Anti-Submarine Detection Investigation Committee (ASDIC) until 1948) is a technique that uses sound propagation under water to navigate...
The Apollo Guidance Computer (AGC) was the first recognizably modern embedded system, used in real-time by astronaut pilots to collect and provide flight information, and to automatically control all of the navigational functions of the Apollo spacecraft. ...
Wire wrap construction can result in assemblies which are inherently more reliable than printed circuits - connections are less prone to fail due to vibration or physical stresses on the base board, and the lack of solder precludes corrosion, dry joints, etc. The connections themselves are firmer and possibly have lower electrical resistance due to cold welding of the wire to the terminal post at the corners. Cold or contact welding was first recognized as a general materials phenomenon in the 1940s. ...
Overview
The electronic parts sometimes plug into sockets. The sockets are glued with cyanoacrylate (or silicone glue) to thin plates of glass-fiber-reinforced epoxy. A socket generally designates a cavity or region used for fitting and connecting some specific device. ...
This article does not cite its references or sources. ...
Silicone caulking can be used as a basic sealant against water and air penetration. ...
Epoxy or polyepoxide is a thermosetting epoxide polymer that cures (polymerizes and crosslinks) when mixed with a catalyzing agent or hardener. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A. The first commercial attempts to prepare resins from epichlorohydrin occurred in 1927 in the United...
The sockets have square posts. The usual posts are 0.017 inches (432 micrometres) square, 1 inch (25.4 mm) high, and spaced at 0.1 inch (2.54 mm) intervals. Premium posts are hard-drawn beryllium-copper alloy plated with a 0.0025 inches (64 micrometres) of gold to prevent corrosion. Less-expensive posts are bronze with tin plating. General Name, Symbol, Number beryllium, Be, 4 Chemical series alkaline earth metals Group, Period, Block 2, 2, s Appearance white-gray metallic Atomic mass 9. ...
For other uses, see Copper (disambiguation). ...
Assorted ancient Bronze castings found as part of a cache, probably intended for recycling. ...
General Name, Symbol, Number tin, Sn, 50 Chemical series poor metals Group, Period, Block 14, 5, p Appearance silvery lustrous gray Atomic mass 118. ...
30 gauge silver-plated soft copper wire is insulated with a fluorocarbon that does not emit dangerous gases when heated. The most common insulation is "kynar". American wire gauge (AWG), also known as the Brown and Sharpe wire gauge, is used in the United States and other countries as a standard method of denoting wire diameter, especially for nonferrous, electrically conducting wire. ...
General Name, Symbol, Number silver, Ag, 47 Chemical series transition metals Group, Period, Block 11, 5, d Appearance lustrous white metal Atomic mass 107. ...
For other uses, see Copper (disambiguation). ...
HAHAH CHANTAL IS A WEIRDOFluorocarbons are carbon-fluorine compounds (DUH, SILLY!!!) that often contain other elements such as hydrogen, chlorine, or bromine. ...
Kynar is the Arkema trade name for polyvinylidene fluoride, a fluorocarbon material typically used as insulation for wire-wrap wire. ...
The 30 AWG Kynar is cut into standard lengths, and then stripped of insulation for one inch on each end. American wire gauge (AWG), also known as the Brown and Sharpe wire gauge, is used in the United States and other countries as a standard method of denoting wire diameter, especially for nonferrous, electrically conducting wire. ...
A special tool called a "wire wrap tool" has two holes. The wire and a quarter inch (6.35 mm) of insulated wire are placed in a hole near the edge of the tool. The hole in the center of the tool is placed over the post. A modern hammer is directly descended from ancient hand tools A tool or device is a piece of equipment that most commonly provides a mechanical advantage in accomplishing a physical task. ...
The tool is rapidly twisted. The result is that 1.5 to 2 turns of insulated wire are wrapped around the post, and atop that, 7 to 9 turns of bare wire are wrapped around the post. The post has room for three such connections, although usually only one or two are needed. This permits manual wire-wrapping to be used for repairs.
The turn and a half of insulated wire help keep the wire from fatiguing where it meets the post.
Above the turn of insulated wire, the bare wire wraps around the post. The corners of the post bite in with pressures of tons per square inch (MPa). This forces all the gases out of the area between the wire's silver plate and the post's gold or tin corners. Further, with 28 such connections (seven turns on a four-cornered post), a very reliable connection exists between the wire and the post.
There are three ways of placing wires on a board.
Manual Wire Wrap A manual wire wrap tool resembles a small pen. It is convenient for minor repairs. Wirewrap is one of the most repairable systems for assembling complex electronics. Posts can be rewrapped up to ten times without appreciable wear, as long as new wire is used each time. Slightly larger jobs are done with a manual "wire wrap gun" with a geared and spring loaded squeeze grip to spin the bit rapidly. Such tools were used in large numbers in American telephone exchanges in the last third of the 20th century, usually with a bigger bit to handle 22 or 24 AWG wire rather than the smaller 28 or 30 AWG used in circuit boards and backplanes. The larger posts can be rewrapped hundreds of times. They persisted into the new century in distribution frames where insulation-displacement connectors had not taken over entirely. central office = Exchange building in the U.S. telephone exchange = Exchange building in the UK, and is also the UK name for a telephone switch, and also has a technical meaning in U.S. telecoms telephone switch is the U.S. term, but is in increasing use in technical UK...
In telephony, a distribution frame is a closet or area set aside which contains equipment which multiplexes users transmission mediums over a higher-capacity medium. ...
An insulation displacement connector or Insulation piercing connector is a connector that pierces the insulation on a wire to make the connection removing the need to strip the wire before connecting. ...
Semiautomated Wire Wrap Semiautomated powered wire-wrap systems place "wire-wrap guns" on arms moved in two dimensions by computer-controlled motors. The guns are manually pulled down, and the trigger pressed to make a wrap. The wires are inserted into the gun manually. This system lets the operator place wires without worrying about whether they are on the right pin. The computer puts the gun over the right pin.
Semi-automated wire wrapping is unique among prototyping systems because it can place twisted pairs, permitting complex high frequency computer and radar systems.
Automated Wire Wrapping Automated wire-wrap machines, as manufactured by the Gardner Denver Company in the 1960s and 1970s, were capable of automatically routing, cutting, stripping and wrapping wires onto an electronic "backplane" or "circuit board". The machines were driven by wiring instructions encoded onto punch cards, Mylar punched hole tape, and early micro computers. Punched cards (or Hollerith cards, or IBM cards), are pieces of stiff paper that contain digital information represented by the presence or absence of holes in predefined positions. ...
Mylar is a trade name of DuPont Teijin Films of Hopewell, VA, United States, for biaxially-oriented polyethylene terephthalate (BOPET) polyester film used for its high tensile strength, chemical and dimensional stability, transparency, and electrical insulation. ...
The earliest machines (14FB and 14FG models, for example) were initially configured as "horizontal", which meant that the wire wrap board was placed upside down (pins up) onto a horizontal tooling plate, which was then rolled into the machine and locked onto a rotating (TRP table rotational position of four positions) and shifting (PLP = pallet longitudinal position of 11 positions) pallet assembly. These machines included very large hydraulic units for powering the servos that drove the ball screw mounted "A" and "B" drive carriages, a 6' tall electronics cabinet loaded with hundreds of IBM control relays, many dozens of solenoids for controlling the various pneumatic mechanical subsystems, and an IBM 029 card reader for positioning instructions. The automatic wire wrap machines themselves were quite large, 6' tall and 8' square. Servicing the machines was extremely complex, and often meant climbing inside them just to work on them. This could be quite dangerous if safety interlocks were not maintained properly; there were rumors throughout the industry that some fatalities/serious injuries had actually occurred.
Later, somewhat smaller machines were "vertical" (14FV) which meant the boards were placed onto a tooling plate with pins facing the machine operator. Gone were the hydraulic units, in favor of direct drive motors to rotate the ball screws, with rotary encoders to provide positioning feedback. This generally provided better visibility of the product for the operator, although maximum wrap area was significantly less than the Horizontal machines. Top speeds on horizontal machines were generally around 500-600 wires per hour, while the vertical machines could reach rates as high as 1200 per hour, depending on board quality and wiring configurations. A ball screw is a threaded shaft designed to provide a raceway for ball bearings so that it can act as a low-friction worm gear, applying thrust loads. ...
A rotary encoder, also called a shaft encoder, is a digital electronic device used to convert the angular position of a shaft or axle to a digital code. ...
Wires would be routed over the board, using "dressing fingers", and carriages would lower the A and B wrapping bits onto the board. The process for wrapping a wire was as follows (Note: the "A" carriage was on the right, while the "B" carriage was on the left). Machine carriages would meet at the next "A" carriage X/Y wire routing position, and the wire feed and stripper assembly located just under the "A" carriage would clamp the supply wire and feed it (push) to the "B" carriage. The "B Gripper" on the B carriage would accept the wire by clamping it, once limit switches in the strip and feed assembly indicated they had completed the feed cycle. Next, the "B" carriage would move "X" (to the left) to the first wire routing position, pulling the supply wire as it moved through the feed assembly from the supply reel, and the "B" "dressing finger would pivot down over the wire. Once the limit switch for the dressing finger indicated it was down, the "B" carriage would move "Y" to the target pin. The "A" carriage dressing finger would then pivot down, and the "A" carriage would move "Y" to its target pin, still pulling supply wire as it moved. Once all wrapping bits and dressing fingers were in position, the cut and strip assembly would retract, stripping the trailing edge of the wire on the "A" side (and simultaneously stripping the leading edge of the next wire). The "A" gripper would clamp the wire against the wrapping bit, and the wrapping tools would close the bits, which meant the outer bit sleeves would retract, pulling both wire ends up into the bits. Once the wire was safely loaded into the wrapping bits, the "A" and "B" grippers would open, and the A and B tools, along with the dressing fingers, would lower "Z" onto the pins. Once the designated "Z" level had been reached (again, sensed by more limit switches) the pneumatic tools would spin, and backpressure would allow the tools to raise up slightly as the wire wrapped around the pins. Waste insulation (transferred from the "A" carriage cut and strip assembly to the "B" carriage during wire feed) is ejected into the waste container at the far left side of the "B" carriage while the wires are wrapped. Finally, the "A" and "B" tools are raised "Z", dressing fingers are retracted, and the carriages regroup for the next cycle.
Use of Electronic Design Automation In wire-wrapping, electronic design automation can design the board, and optimize the order in which wires are placed. PCB Layout Program Electronic design automation (EDA) is the category of tools for designing and producing electronic systems ranging from printed circuit boards (PCBs) to integrated circuits. ...
The first stage was that a schematic was encoded into a netlist. This step is now done automatically by EDA programs that perform "schematic capture". A netlist is conceptually a list of pins, with each pin having an associated signal name.
The next step was to encode the pin positions of each device. The easy way to do this is to encode lettered rows and numbered columns where the devices should go. The computer then assigns pin 1 of each device in the bill of materials to an intersection, and renames the devices in the bill of materials by their row and column.
The computer would then "explode" the device list into a complete pin list for the board by using templates for each type of device. A template is map of a device's pins. It can be encoded once, and then shared by all devices of that type.
Some systems optimized the design by experimentally swapping the positions of parts and logic gates to reduce the wire length. After each movement, the associated pins in the netlist would be renamed. Some systems could also automatically discover power pins in the devices, and generate wires to the nearest power pins. A logic gate is an arrangement of electronically-controlled switches used to calculate operations in Boolean algebra. ...
The computer program then merges the netlist (sorted by pin name) with the pin list (sorted by pin name), transferring the physical coordinates of the pin list to the netlist. The netlist is then resorted, by net name.
The programs then try to reorder each net in the signal-pin list to "route" each signal in the shortest way. The routing problem is equivalent to the travelling salesman problem, and is therefore NP complete, and therefore not amenable to a perfect solution. One practical routing algorithm is to pick the pin farthest from the center of the board, then use a greedy algorithm to select the next-nearest pin with the same signal name. If a salesman starts at point A, and if the distances between any two points is known, what is the shortest round-trip the salesman can make which will visit all points once and return to point A? The travelling salesman problem[1] [2](TSP) is a problem in discrete...
In complexity theory, the NP-complete problems are the most difficult problems in NP (non-deterministic polynomial time) in the sense that they are the ones most likely not to be in P. The reason is that if one could find a way to solve any NP-complete problem quickly...
Once routed, each pair of nodes in a net becomes a wire, in a "wire list". The computer then reads incidental information (wire color, order in the net, length of the wire, etc) in the netlist and interprets it to renumber the wire list to optimize the ordering and direction of wires during production. The wire list is then resorted by the wire numbers.
For example, wires are always "top and bottomed". That is, wires alternate between high and low as they connect a series of pins. This lets a repair or modification occur with the removal of at most three wires.
Long wires are usually placed first within a level, so that shorter wires will hold longer wires down. This reduces vibration of the longer wires, making the board more rugged in a vibrating environment such as a vehicle.
Placing all the wires of a certain size makes it easier for a manual or semiautomated wire-wrapping machine to use precut wire. This especially speeds up manual wrapping.
Wires of different colors can also be placed together. Most wires are blue. Power and ground wires are often made with red and black. Clock wires (or other wires needing special routing) are often made yellow or white. Twisted pairs are usually black and white.
Another optimization is that within each size and color of wire, the computer selects the next wire so that the wrap head moves to the nearest pin. This can save up to 40% of the wrap time, almost getting two wire-wrap machines for the price of one. It also reduces wear on the wire-wrap machines.
Finally, the direction of placing a wire can be optimized for right-handed wire-wrap people, so that wires are placed from right to left. In a semi-automated wire-wrap system, this means that the wrap head moves away from the user's hand when placing a wire. The user can then use their strong hand and eye to route the wire.
Lastly, the sorted, optimized wire list is then printed out for use by machine operators, and turned into a tape or card deck for the machine. Machine-readable copies of this valuable production data are often archived at the same time.
See also Point-to-point construction is the way most electronics were constructed before the 1950s. ...
This page is a candidate to be copied to Wikibooks using the Transwiki process. ...
Veroboard is the trademark name of the electronics prototyping board manufactured by the Vero Electronics company. ...
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