How to draw helical coil with parallel conductors

Can you define the "line" as an extension of two dots of copper spaced apart and get the software to extend the two-dot pattern as a spiral?

Technically speaking, if you can write one single line spiral with an offset start and enough space between the turns, you should be able to write second spiral, slightly offset in the opposite sense, to fit inside the other.

If the first spiral is offset to the left and turns up in the first 90 degrees, and the second spiral is offset to the right and turns down in the first 90 degrees, it ought to work.

Making the starting pads big enough accommodate a solder pad makes the start messier, but it you ought to be able to get it to work.

How about drawing a spiral with a width equal to the two conductors plus the spacing. Then draw the same spiral with a width of the spacing, but make it a negative image subtracting from the first conductor, splitting it in two.

I think not all PCB houses like negative images mixed with positive, but others are ok with it. Or maybe program generate the Gerber code. Gerber codes are vaguely like a programming language. It shouldn't be too hard to write a small program that will spit out the right codes.

On Tue, 10 Nov 2015 18:39:38 +1100, Ken Morrow Gave us:

Try putting one on an additional layer (or a "work-up zone" in another area of the layout) with the second spacing in mind, then cutting and pasting it into the original layer/location. The central exits need to come straight across the set, so hard hook-up wire or a vias with the returns on it.

I wrote a small utility to make serpentine heaters as BMP files, then imported them into Eagle. Bumpfiles are pretty simple.

Cheers

Phil Hobbs

Some PCB layout programs can import Autocad files as copper.

My PCB program (KiCad) couldn't do spirals at all, so I made a Perl script that read in the Gerbers, applied the requisite traces, and barfed out the new Gerbers.

Gerber files are just text, and if you identify the right spots in the files it's pretty easy to add traces & vias & whatnot. Ditto drill files.

Your best bet is to say "ah hah! I'll go do that in my favorite text processing language", but if you want, you can send me an email and I'll send you the program. It'll be poorly commented and not terribly scrutable (that's part way to "inscrutable", yes?), and it's pretty fixed in what it does, but it may be a help to see how to modify a Gerber file.

That sounds like an EC control nightmare in the making.

You could also edit the PCB file since it is text too, or probably put it into a component footprint too. Those might be easier to edit later, for less-technical cow orkers.

I hadn't thought of it at the time, but a Perl script to make the footprint may be a good thing.

KiCad will generate a design rules check error if you have a component with an internal short, so you have to play _some_ sort of trick to make it happen. I prefer to make the board to pass DRC and then patch it up for production later.

This may be a dumb question, but why don't all PCB layout programs talk in *.DXG/ DXF. Then I could layout my part once.

George H.

Yeah, as long as you're going to destroy the tool chain, do a good job!

There were a few PCB layout systems that were built on top of Autocad. They weren't successful.

PADS will import or export anything, including symbols and decals, as text files. Sometimes it's handy to edit the text files, manually or with some program. It would be perfectly reasonable to write a program to create a spiral component for PADS, as an ascii file. It would go into the PADS part library like any other part.

You could do it with a zillion line segments, or a series of arcs.

We use very little of the standard PADS library. Most of the parts that we use are ones that we create.

On Tue, 10 Nov 2015 18:25:55 -0800 (PST), George Herold Gave us:

Back in '86 I used tape at 4X on mylar and a big drafting board and we had our own camera with which we took photos from ten feet away to send run ready artwork to the board maker with. That was two layer work..

We also used Autocad 2.0ish on 286 machines and the board maker had to translate those output files into a gerber file, which was far more expensive for a mere 2 layer work up.

The CAD workstations that were around at the time were thousands of dollars outside our budget, and there were no PC based CAD engines out there yet.

When they did get started up with names like OrCAD, etc., they were quite expensive and the output was proprietary form, and they deliberately did not "talk" with Autocad output file formats for input data or otherwise.

That may well be were this is rooted.

Actually, ANY modern CAD package which has numerical control run ready output should be able to be used as input data structure media for any other CAD package, but this is, alas, not the case.

I am currently using Siemens' free CAD 2D package "Solid Edge". It too does not "save" its generated 'work' in easily communicable file formats.

I am currently installing the also free Nat'l Instruments' "MultiSIM Blue" 'product' to see how it is structured and what degree of 'robustness' it has within its borders.

This is all like Russia and the US and their 'cold war'.

I personally liked "Tango PCB", which got bought then abandoned by its now 'owner'. Yet they were more than happy to take our $450 per year support 'fee' for four years after they actually ceased supporting the product.

I still use Tango for anything with 4 layers or less. Fuck the 'owner' who abandoned it.

It was written in Pascal, and would be great to reverse engineer and re-release under Linux. But I'll have to see how this "Mouser/National Instruments collaboration" works, or if it is a handcuffed abomination Spamming the user to buy "the full bore package".

I am bored with this bait and switch shit.

Microsoft started it when they sold software but actual "service" cost more. This was an OS which has been notoriously broken as the disc masters hit the presses.

I used to buy something and it had a REAL warranty. My Pioneer Stereo came with schematics. Later, I had to buy them because they were more complicated and large and were rendered on microfiche. Now, such things are not even available to the consumer.

Now, when my broken but customized Sony PS3 .would be sent in for repair, they would not fix it and return it. They send you a baseline refurb and trash your unit. So, I lose my HD upgrade and case customizations (neither of which break the warranty)because they are too stupid to work on MY unit and REAPAIR MY UNIT and send MY UNIT back to me.

They also advertized the machine's capacity to "run Linux" which it did perfectly, until they also reneged on that claim with a firmware/OS upgrade which killed all the work I had done on the machine. And simply cloning the drive would not work as it was tied to the machine via internal serialization, and the same held true for the broken DVD drive which only THEY could replace, but were even too f***ed in the head to do that.

Sony is actually the worst in this regard. And the consumer has no avenue of force to get them to comply even with the claims they make under which they SELL the item to start with.

I am sure Apple is right there in that mix with them. Try running Linux on one of their OSX driven laptops. No I do not refer to a virtual box scenario. I am talking about excising the main start up OS completely. Very difficult to do.

It is truly a sad world since these bastards would actually sell MORE product if they were not such retarded prudes.

A friend of mine did PCB layout for a living, he used plain Autocad to do it. This was in the early eighties, before the ICM PC standard had totally taken over. Then made memory expansion boards himself, in the sink, and used them to upgrade his machine to run autocad better.

He generated his own photoplots directly, using a LED strapped to an old pen plotter!

Seems to me if you drew a spral that did not go all the way to the center, so that the center pad was slightly offset, and then duplicated the spiral with a 180 degree rotation, but at the same center, they would nest into each other without shorting. I know I could do this in a few mouse clicks in Protel 99SE, once I had the spiral created. (I have no idea how to do a spiral in Protel99, I don't THINK there is such a primitive available.)

This might be a case for creating it with a C program or something and then importing the primitives with an ASCII import.

Jon

In my day, we defragged hard disks by editing the inodes by hand. With magnets.

Cheers

Phil Hobbs

I believe this was a time when many still used tape to lay out PCBs. Layouts were mostly single or double sided and design rules were... not so important. Layout was an easy job really. Very visual and intuitive, but very labor intensive. Once things got a bit more complex with pin counts escalating, trace widths decreasing and layer count bumping up, layout got to be much more complex so the specialized software became much more necessary.

Not perfectly spiral but you can create two circles in CorelDraw. one being the center and the other the circumference.

Align centers.

Using the shape tool convert each to a half circle.

Select them and blend with the number of steps equalling the number of desired turns.

Duplicate it, mirror horizontally, and then bring them together but offset by one turn.

That gives you two parallel spiral-like windings.

Not sure how to get this into a PCB file though.

Klaus Jensen