The electronic schematic symbol for a twisted....

[Pablo]

Anyone know the electronic schematic symbol for a twisted wire pair? And indicating the twists per inch?

Fairly vigorous debate, believe it or not. What is the proper symbol?

(I have my opinion, others and supplier have theirs)

 

[StevieC]

I went to school for Computer Engineering and can't remember and my books are packed away because I'm moving but OVERK1LL should know he is a network engineer.

PM him.

 

[brianl703]

I have always seen it denoted this way:

I believe the schematics in the ARRL handbook use the same symbol.

Also, I have never seen any twisted pair wire sold with a twists-per-foot specification. The performance criteria for twisted pair is a tad more complex than that. For example, the type of insulation used on the wires changes the electrical characteristics of the twisted pair, and if you have more than one twisted pair in a cable they must have different twists per foot to avoid crosstalk.

 

[StevieC]

That looks right to me, but the wires are less circular and more zig-zaggy if I remember.

 

[brianl703]

It's basically two superimposed sinewaves.

 

[Tempest]

Originally Posted By: brianl703
It's basically two superimposed sinewaves.

This was always the way it was back when I worked at a wire house. They would just state twists per inch (if it mattered) and overall length after twisting.

Every customer had a slightly different symbol though.

 

[Pablo]

Originally Posted By: Tempest
Originally Posted By: brianl703
It's basically two superimposed sinewaves.

This was always the way it was back when I worked at a wire house. They would just state twists per inch (if it mattered) and overall length after twisting.

Every customer had a slightly different symbol though.


What about a drawing showing both wires parallel, a racetrack capturing both (at the wire exit point) with a "P" in the center of the track? (nothing else indicated). To me this says nothing of twisting, it indicates the wires should be P - protected in sleeving. If this race track had a ground symbol attached, then it would be some type of metal shield, braided or otherwise. But not indicating twisting. IMHO.

 

[Tempest]

Sounds like cruddy drawings to me (without actually seeing them). If they used parallel wires without a LARGE notation to explain that they really want twisted wires + TPI then their draftsman dropped the ball.

Simply calling out "P" really isn't very helpful either as there are numerous types of wire wrap. Spiral wrap, heat shrink, Teflon...

There should always be a first article or prototype submitted to the customer to avoid such problems before production.

 

[doitmyself]

I did find this symbol at the CAD pdf, just FYI. Everything else seems to be what Brian posted, sometimes the "circles" are elongated more horizontal or vertical.

http://www.rand.com/imaginit/1/pdfs/technology/software/ace-jic_twn_final.pdf

Well, I can't paste the image.....check bottom of page 3.

 

[OVERKILL]

Twisted pair:

 

[Papa Bear]

or .... Twisted Pair

 

[OVERKILL]

Nice! LOL!

 

[Shannow]

Adding a few more products to the line Pablo ?

http://www.littlemountainsmudge.com/mobiuscontinuosknot.htm

 

[andyd]

All wire ,cable, have a spec printed on the jacket. Cat 5, is a spec. When I was ordering cable in my phone days, I used a Graybar or Anixter catalog that had cable listed by its particular spec.

 

[StevieC]

Originally Posted By: Papa Bear

or .... Twisted Pair