WWiirree WWrraapp iiss SSttiillll UUsseeffuull It is also easy and fun

By: Nicholas C Lewis (based on Is Easy by Mitch Altman, Andie Nordgren, Jeff Keyzer)

Distribute widely! wrap was once During the wrapping very common for process, a wire is pulled prototyping circuits. around a terminal by use Is is much more of a wrapping tool. reliable than solder- less , and After the wrapping can be easier and operation and the cheaper than having connection is stabilized PCBs made. the compression between wire and terminal corners While surface mount is from 50,000 psi technology and lower (35Kg/mm2) to 100,000 psi cost PCB (70 Kg/mm2). manufacturing has reduced its use it Four turns of wire (16 contact points) provide a can still be a very contact surface equivalent to the cross section useful technique. of the wire. The connection resistance is less than the resistance of one inch of the wire.

These are wire wrap A so lid, roun terminals. con d wire is nections. used fo mm The wir r wire wr diameter es range ap w (AWG 30 from 0. 25 ith hand- - AWG 18) mm - 1. 0 m held tool and are Some are designed to aterials s. The t connected are: PVC, ypical in solder to components Tefzel. Kynar, M sulation ilene, Te flon, and

The most common wire for And others are for circuit board work is AWG components to push 30 with Kynar insulation. into.

se ther the rly toge s is a Wire Wrap tool. d prope rrosion- Thi When use ate a co ings cre ction on three th t conne . gas-tigh terminal safe and s of the p corner the shar

Wire Maximum The tool wraps the solid round Elongation wire tightly around the edged terminal under mechanical tension. There are three different sorts Maximum of wrapping bits: Modified, Compression Standard, and C. S. W. (cut, strip, wrap) bits. The most common of these is the modified bit. Terminal

2 Electronic circuits There are many ways to connect electronic parts are made by together. connecting electronic parts together. ) "

1 Unlike soldering parts to .

0 a , ( wire wrap generally m

m involves placing 4

5 components together on .

2 perforated fiberglass 2. 54mm (0. 1") board (perf board).

Rou re All the parts have , nd leads wi Solder he wo ll not called leads, sticking out rk for wire wrappi nd here of them. ng as corne a are r rs equired for strong connection se leads s. Most of the round. are push in

Othe r leads are rec tangular bu ar t e too short (such as on ICs). This is why we need the wire wrap terminals and sockets.

When wire wrapping you must follow your schematic After detailed as your perf board does not connect anything. review of your schematic you need Before you start to decide what kind wiring go over your of terminals you are schematic carefully going to use. as this is the road map you will follow.

This depends on what components you are Think about the using and whether colors of wire you you want to solder want to use and parts or j ust press where each component them in. is going to go.

3 To place the IC we begin by placing an IC Lets start with an socket in the perf board. Integrated Circuit (IC).

The Mark

Pin 1 You can glue the socket (super glue works well) ICs have many pins to the perf board to help hold it in place while and a mark that wrapping. indicates where pin If your board has pads around the holes #1 is located. you can tack solder a few terminals.

It is good to place most of the Then you turn the components before you board over so you can start wrapping. connect the wires.

If any of the Try components in a variety of positions to terminals try to fall determine the best layout to simplify the wire out j ust push them routing. Experiment before wiring since changes back in or secure them are much easier to make at this time. with glue/solder.

Before you start Choose a color scheme wrapping you can place for the wires so that red an ID marker over the they are easy to pins of the IC trace later when red red black sockets. debugging. red Red is commonly used for positive voltage lines (Vcc) and black blue blue for ground lines. It is good to reserve green red and black for blue these purposes. black These help you find the pin number without black black counting. The notch on Using the same color for every connection makes the ID marker should it hard to trace wires and troubleshoot. line up with the notch In this example blue is used for the signal lines on the socket. from IC1 and green is used for the "extra" wire between the LED and R3. 4 Before making a connection you must Slip the wire into the small strip about 25mm (1") of insulation hole at the side of the tool. from one end of the wire.

This length will provide a good number of wraps around the terminal. Be sure to slip the wire in far enough. With a standard bit the Most wire wrap tools include insulation should rest on the a basic wire stripper. inner face and with a modified bit the insulation should slip inside a small distance.

Then slide the center hole of the tool over the terminal.

Be su re tha the s t the ide ho wire is in le and is in the c the enter termin hole. al

While holding the wire start Hold on to the insulated portion turning the tool clockwise to of the wire to stop excess make the wrapped connection. insulated wire from wrapping around the terminal. Pinching it against the board works well. Always rotate the tool in the same direction. Do not push too hard or pull backwards on the tool while turning or you will either overlap the turns or leave gaps.

Keep rotating until all of the stripped wire is on the terminal and the tool comes off freely. This should result in approximately 6 to 12 wraps around the pin.

Then pull t termi he to nal, ol off your and ta the perfec ke a l conne t wir ook at ction! e wrap

5 Now route the wire to the other end A good wire wrap connection has 6-12 of the connection, cut it to length even wraps and insulation that comes (include the 25mm (1") you are about all the way to the terminal.

to strip), and strip the end. Then ) ) s l

you are ready for your next wire r a e n n

wrap connection. n n o i r o i m o i t r c t c e c e t + e n 3 n n o n o t d o c n c t u " s o Not Good "

Good d u r d r j a e a Provide clearance around other i d n f n n o terminals to avoid bending the i o a i d i t t terminals and/or damaging the wire. o t s a m a " l " l

It is better to make the wire a u u d s d s

little long, if it gets too short o n o n o i o i

you' ll have start over. G ( G (

Be sure that the If the wire If the wire insulated portion of overlaps has gaps the wire starts right lower wraps between at the pin (standard you put too wraps you wrap), or is wrapped much down pulled up around at least 3 pressure on on the tool corners (modified the tool while wrap). while wrapping. wrapping. If there is uninsulated wire extending from the terminal it may short to another terminal.

You should avoid placing the Always place wrap too close the wrap as to the tip of a low as terminal possible on or too the terminal. close to a prior If it is wrap. high on the terminal than you lose places to put wraps.

All of these conditions are fixable. If you have any of them j ust remove the wrap and start again.

6 To remove a wrapped wire: insert the Continue to turn until the tool over the wrapped terminal the wrap is loose enough and turn counter clockwise to loosen to pull off. the wrap.

Then simply remove the wire.

If the wire can not be unwrapped (i. e. it is blocked by another wrap) then you can also j ust cut the wire close to the terminal and leave the wrap.

through the s you work organized a miss any. Be you do not Check off each nections so \ con \ \ / connection on your / schematic diagram Sometimes it works best to as you go. use one color at a time. Other times it is easier if / / you make the connections in \ a logical order, such as in the path that the / \ / When you think you electricity follows, or to are done double-check make connections one / every connection. component at a time. / \

The Golden Rules of Wire Wrapping

1. Wrap each connection as low as possible. 2. Only two connections on one terminal. (save the extra space for repairs and changes) 3. Wrap both ends of a wire at the same level. 4. Wrap long wires first. 5. Unwrap the wire to remove a connection. (or j ust clip off the wire and leave the wrap) Do not reuse unwrapped wire.

Sometimes you must violate one of the golden rules. The most common reason for this would be where the rules contradict (i. e. Wrap as low as possible vs. wrap both ends at the same level).

If that is the case follow the rules in order and if a later rule is broken it is OK.

7 If you like wire If you really want to go wrapping, and want all out, or if you think to wire wrap well, you will be doing a lot of you’ ll want to wire wrapping, buy some good you can buy a decent tools. But you manual wire wrap gun do not need for about US$150, to spend a lot of money to get them. or an electric wire wrap gun for You can buy a decent about US$400. wire wrap tool (like the one shown, or one shaped like You can sometimes a precision screw driver) find bargains on for about US$30. these at surplus stores.

Buy a 100ft roll of wire wrap AWG30 wire You might also want for about US$10. You Then you’ ll a soldering iron (about US$30), should get several need wire spools in different cutters, colors. for another US$6. long nose pliers (about US$6),

wire strippers (about US$10),

You will also need wire wrap sockets and safety glasses (as low as (US$2-3ea) and/or US$2). solder terminals (US$10 for 100).

hare! y and S This comic was made to Enj o support

Narration and Artwork by Nicholas C Lewis Wrapduino http: //NicholasCLewis. com a wire wrap Arduino clone Translate it, use it, spread it, color it, by Nicholas C Lewis teach with it! of NerdCreationLab. com http: //NerdCreationLab. com/WireWrapComic

Based on "Soldering is Easy" by Mitch Altman, Andie Nordgren, Distribute widely! & Jeff Keyzer http: //mightyohm. com/soldercomic

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