I think there is some mis-understanding, Postscript is a page description that is independent of the resolution. Once the image is rendered i.e. onto an A size page at 300dpi it is a bitmap. EPS is used to contain individual graphics and is based on Postscript. The rest of Bullzip's options are rendered to a set resolution. When you open a PDF in Acroread it is re-renderd everytime you zoom or pan it, this is lost in TIFF, BMP or JPG etc.
The problem is control of what is printed, the issue with ExpressSCH is that a printed page includes the whole virtual drafting sheet and needs editing to get just your circuit out of it. Possibly the full version of Acrobat can do that and keep it vector based. Windows Metafile is what we use here sometimes but I think the prefered open source thing is SVG.
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Bob --
There has developed two camps about which approach is better, designing a VFA or a CFA. I think we are pretty close to done with VFA as there are many sources of info and design. I would like to propose a completely new book be started on the CFA approach for audio. there is plenty of interest and presents a win-win for everyone.
Thx-Richard Marsh
There has developed two camps about which approach is better, designing a VFA or a CFA. I think we are pretty close to done with VFA as there are many sources of info and design. I would like to propose a completely new book be started on the CFA approach for audio. there is plenty of interest and presents a win-win for everyone.
Thx-Richard Marsh
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Mike, Jan
Here is a summary of mostly free tools (some for publication quality) for schematics.
Wikipedia:WikiProject Electronics/Programs - Wikipedia, the free encyclopedia
Here is a summary of mostly free tools (some for publication quality) for schematics.
Wikipedia:WikiProject Electronics/Programs - Wikipedia, the free encyclopedia
Hi Richard,
Seems like an interesting idea - maybe not a book, but maybe a section in my Second Edition. I'll have to bone up on them some.
Seems to me the classic 2-transistor RIAA preamp was a CFA. I think the discrete equalizer amplifiers I used for Picturephone back in 1971 were CFAs, and the advantage was constant loop gain with frequency in spite of the EQ. I think they had an EQ tolerance of about 0.05 dB out to about 1 MHz.
Cheers,
Bob
Only snag is they're really not "CFAs" at all.
Come on Mike, can't we talk about amplifiers where the feedback network is intimately part of the forward transfer function as different. We all understand this, why hang up on what we call it.
The vector graphics formats like PDF or Postscript are indeed independent of resolution. The vector format says: draw a line from x1,y1 to x2,y2. The idea is that whatever the size of the drawing, it is always a perfect straight line (limited only by the medium resolution, and for offset printing the standard is 300 dpi).
So if you resize a vector drawing it will not change in resolution.
A bitmap for instance says: 'turn on these pixels'.Then if you resize it, say 1.5 times as large, it tries to turn on half a pixel extra to the original one to keep up the same appearance. But half pixels don't exist so a full additional pixel gets either turned on or not, and that will give the picture it's blocky appearance.
A virtual PDF printer like Bullzip will take the input file that says: draw a line from x1,y1 to x2,y2 and instead of putting it on paper in the selected size, will put it in a PDF file so you can then resize it with no change in resolution.
EPS, WMF and EMF are similar and will also resize with no loss. The thing with WMF is that it actually contains both a vector version as well as a rasterized (like bitmap) version in the same picture. When you place it in a Word document it remains vector based UNTIL you edit it in Word, then it reverts to rasterized, and if you then take it from the Word file and save it, it is no longer vector based but bitmap based.
Bit me a few times before I got it; actually I thought they were pulling my leg, it seemed insane, but it is true!
jan
My CAD suite lets me set an output area that allows printing only a selected portion of the work area.
Most layout programs like those from Adobe allow you to cut out a wanted portion of a bigger area, and as it is in PDF, the cut out portion is still in PDF and can be resized with no change in resolution.
jan
? for you Jan, or anyone else
How can I measure dimensions on a pdf, to see if the output layer data are 1:1 from the gerber data, that I am using as the source?
I am trying to get Mihai to make some pcb's for me on the cheap. One pcb in particular has a 40 DFN 0.5mm pitch part on it.
http://www.diyaudio.com/forums/vend...-circuit-boards-starting-0-0375-euro-cm2.html
He says he will only accept pdf, jpeg, tiff at 1200dpi.
I always print out the layers on paper as a test to see that I did not screw-up a footprint or something else. I know this has its inaccuracies, paper stretch, ink bleed etc, but it is for sanity reasons only, not to fab from.
I have two options for this fab method, print from GerbTool or Orcad itself.
Thx Rick
How can I measure dimensions on a pdf, to see if the output layer data are 1:1 from the gerber data, that I am using as the source?
I am trying to get Mihai to make some pcb's for me on the cheap. One pcb in particular has a 40 DFN 0.5mm pitch part on it.
http://www.diyaudio.com/forums/vend...-circuit-boards-starting-0-0375-euro-cm2.html
He says he will only accept pdf, jpeg, tiff at 1200dpi.
I always print out the layers on paper as a test to see that I did not screw-up a footprint or something else. I know this has its inaccuracies, paper stretch, ink bleed etc, but it is for sanity reasons only, not to fab from.
I have two options for this fab method, print from GerbTool or Orcad itself.
Thx Rick
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How do you generate vector graphics with Bullzip? And how do you insert the resulting images into Word?
Of course they're different, but why call them what they're most certainly not, i.e. "Current Feedback Amplifiers"?
because we speak illogical natural languages, with other engineers who have accepted this terminology?
because we want find the parts by the common/"trivial"/"illogical" name in manufacturer's selection guides, find them in search?
Why don't you just adopt a private alternative for the acronym - how about Comlinear's Fraudulent Appellation
And quit bringing it up amongst adults that use their brains to understand ambiguous wordings
because we want find the parts by the common/"trivial"/"illogical" name in manufacturer's selection guides, find them in search?
Why don't you just adopt a private alternative for the acronym - how about Comlinear's Fraudulent Appellation
And quit bringing it up amongst adults that use their brains to understand ambiguous wordings
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Do you have a Mac or a PC? The Mac version of Word natively supports PDF but the PC version does not. I think the only vector graphics that the PC version of Word supports is WMF.
Hi,
This might help: Add a PDF to your Office file - Word - Office.com
Seems to work on my Windows version of Word 2010.
This might help: Add a PDF to your Office file - Word - Office.com
Seems to work on my Windows version of Word 2010.
Bob,
I applaud your open-mindedness in thinking about a section which covers the technical aspects of power amplifier design employing current-feedback principles. As a purchaser of both your first edition (and Douglas Self's fifth edition), I felt that there was a certain body of fairly well grounded technical knowledge on this particular subject which was overlooked in both of these excellent these volumes.
It appears to me (at least) that CFAs are certainly of enduring and ongoing interest to several folks on diyAudio, as well as to some members of the commercial audio industry at large. I have seen many interesting designs on this site, which shows just how creative people can be.
However, this topology certainly doesn't seem to be as well understood in the DIY community, from a basic circuit analysis point of view, as it is in the analog IC design world. The "general purpose" nature of many commercially successful CFA op-amp designs, while interesting from a circuit level perspective, needs to be properly covered in terms of both the advantages and inherent circuit deficiencies. In particular, certain disadvantages of CFAs require some level of design adaptation (i.e. design cleverness) when pressed into audio power amplifier service. Needless to say, I would definitely look forward to a few new chapters which cover this subject matter in more detail.
Indeed, I have found as a designer that many of the advancements in voltage-feedback (VFA) power amplifier circuit design (specifically over the last 5-10 years) are also applicable to the current feedback realm. I'm talking primarily about TIS/VAS distortion reduction techniques at LF and HF, conditional stability and output inclusive compensation techniques, nested feedback loops, improvement of marginal PSRR performance to name just a few. These should all seriously be considered for inclusion, if a new section on CFAs in the second edition of your book actually comes to fruition.
Your ongoing efforts as an author are most appreciated by all of us in the community at large....
Cheers,
Mark A.
Interesting. Clearly that was a new feature in Office 2010. What's annoying is that in the Mac version of Word, when you insert a PDF into the document, Word automatically creates a (fairly low-res) bitmapped version of the image and embeds that in the document too. When the .docx is opened on a Mac, you get the vector-based graphics from the PDF, but when you open it on a PC you get the bitmapped image instead. It's not clear to me why that happens if the PC version does in fact support PDF.