A Lost Art: Wire-Wrapping
this week's Featured Book, I wanted to find something on wire-wrapping.
Although I was not successful at finding a book currently in publication
that is dedicated to wire-wrapping, I did find a great page on
full of information and great high-res pictures. There are plenty more
resources if you do a Google search.
Wire wrapping (w/w) used
the be a very popular method for prototyping circuits when DIP and SIP
packages dominated the electronics landscape. If done properly where
wraps were placed on posts in order to make changes easier and where
care was taken to avoid crosstalk from long parallel signals runs, w/w
was useful at frequencies into the tens of megahertz, even with digital
circuits. I personally have wire-wrapped more than a hundred boards
both as engineering prototypes and as deliverable assemblies for military
equipment. A well-done w/w board can look like a work of art.
used to be machines (maybe there still are) that automatically do the
wire wrapping based on a routing file. Some early schematic layout software
had an option to output a wire-wrap file as well as a standard Gerber
file for PCB fabrication. Wire wrapping is still a very useful option
for breadboarding today even with the predominance of surface mount
parts because SMD-to-DIP adapter products like
Abra, and many others are available. Most of the electronics distributors
sell wire-wrap backplanes, DIP sockets, SMD-to-DIP adapter/breakout
boards, w/w tools and wire, etc.
You might be inclined to think
that wire-wrapped connection is not very secure or high quality, but
the fact is that when done properly, each complete wrap around the square,
sharp-edged post provides four independent low-resistance, gas-tight
contacts. The military and aerospace industry have published volumes
on the science behind wire wrapping and on acceptable methods for performing
it, as well as manufacturing specifications for the w/w posts, wire
and its insulation, and the tools used to attach and remove wraps to/from