A Solderless Printed Circuit Board

The trouble with bread boards is what happens 

when one needs to build something else up. Suppose

there is an easy way to hook up a circuit which

is a bit more like a printed circuit board but is

fast and easy. The lastest method is used here.

Everything that is needed is shown above. First off, all the

circuit components are required. A manual wire wrap tool is shown

at top with some wire wrap wire shown at the left. Now what if

if a PC board is printed out on paper? This is not a new idea.

A "pPCBs (Paper Printed Circuit Board)" idea has been published

on the web at this site. But it is not obvious that wire

wrap has been discussed.  

   Solder side                           Component side

Anyone who has done any amount of PCB layout will be familiar with the two

sides of a PCB. A regular PCB layout just printed out on paper could do

the job. The layout shown above however has imported the artwork from

an Open source PCB layout program located at this site.

This application can export data to EPS files which can then be imported to

a vector application where some documentation has been added. The dimensions to

things like dip pinouts and resistor holes will be maintained at the correct 

spacings. The solder side on the left is where the circuit gets hooked up.

Having a schematic close by can make the PCB layout a little easier. And labeling

all component sizes is convenient. A vector application can do a flip of

the artwork to generate the component side shown on the right. 

This artwork can be found here.   

The two sides can be carefully glued to both sides of an index card

such that the holes all line up. Punch holes in the component side, and

the leads of an inserted component will come out through the holes

on the solder side. 

The manual wire wrap tool has a insulation stripper which can double 

as a lead length measure. When the unstripped wire is inserted till

it just about comes out the other end, it will be stripped to the

optimum length. 

The stripped end of the wire then gets inserted into the groove of the

wire wrap tool. 

Place the tool over a lead on the solder side and twist until all the bare wire

is wrapped around the lead. 

Wire wrap is not as solid as soldering, but it comes close.

If the stripped wire is at the optimum length, several

wraps can be made on every pin. And the bare wire can

be counted on to make contact.

Wire wrap can make a lot of different connections in close

quarters. Documenting component values and where wires go

makes it much easier to hook up everything without

making a mistake.  

This circuit was designed to operate completely off a laptop

using the standard ports. One can use the laptop as an 

oscilloscope while running spice simulations at the same

time. 

The USB port can supply 5volts at 200mAs, and the audio input

port can AC couple in stereo signal at standard audio levels.

Having the circuit work without any debugging is always nice.

With just wire wrap, the circuit is semi-permanent. This 

particular layout might get enough use to encourage adding a 

little solder to all the leads. As it stands right now, all

the wires can be removed, and all the components can be

reused. 

It may be best to avoid trimming component leads in favor 

of looping them. Loops make good scope connections.