Re: gEDA-user: hydraulic symbols and schematics
Hi Bert, Thanks for the additions. -Tom On Thu, Apr 8, 2010 at 1:18 AM, Bert Timmerman wrote: > Hi Tom, > > I like the style of the symbols, great work. > > I will have a look at the company hydraulics symbol lib today and see what > else comes up. > > The company I work uses a lot of hydraulic drive systems. > > BTW: I have forked your repo to have a local version to work on and work > with myself. > > Watch your forkqueue :-) > > Kind regards, > > Bert Timmerman. > > > > >> -Original Message- >> From: geda-user-boun...@moria.seul.org >> [mailto:geda-user-boun...@moria.seul.org] On Behalf Of Tom Hawkins >> Sent: Thursday, April 08, 2010 4:13 AM >> To: gEDA user mailing list >> Subject: Re: gEDA-user: hydraulic symbols and schematics >> >> Thanks for all the input. Here's the little hydraulic symbol >> library I started: >> >> http://tomahawkins.org/gschem-hydraulics.png >> http://github.com/tomahawkins/hydraulics >> >> A bit later I'll looking into path fills, and after that, >> netlisting this into something that can be simulated. >> >> Thanks for your help. >> >> -Tom >> >> >> ___ >> geda-user mailing list >> geda-user@moria.seul.org >> http://www.seul.org/cgi-bin/mailman/listinfo/geda-user >> > > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Stuart Brorson wrote: >> Do you foresee any other difficulties? ... aside from simulating a >> hydraulic circuit with spice or generating a layout. > > Actually, my first thought was: What kinds of simulations (if any) > does one do in hydraulics? Are there any standard simulators? If so, > generating a netlist to feed to such a simulator might be an > interesting hobby project. I think Verilog-A/MS is a tool that people use for simulating a variety of conservative systems, including hydraulics. Hopefully, Icarus Verilog will start moving forward again on that front some- time soon. -- Steve Williams"The woods are lovely, dark and deep. steve at icarus.com But I have promises to keep, http://www.icarus.com and lines to code before I sleep, http://www.picturel.com And lines to code before I sleep." ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Apr 8, 2010, at 2:35 AM, Florian Teply wrote: > Umm, now that you mention Mathematica: Do you know of a way of feeding > from gEDA to Open Source computer math packages like octave or scilab? > Not that i'd currently feel a personal need of it, but i'm curious. Such > information often came in handy when i expected it the least > beforehand... My mathematician son and I sat down at Ales' place with the gang for a code sprint last year and tried to do this with Sage. The snag we ran into is that although it's easy to export netlists to anything with gnetlist, handling models is trickier. The way it works for Mathematica is that the mathematica back end for gnetlist translates attributes to Mathematica expressions in a fairly mindless way. The attribute: model=opamp[bandwidth->bw] attached to U1 turns into the Mathematica expression: opamp[bandwidth->bw]["U1"] It's then Mathematica's job to expand this into equations and concatenate them to the node equations. This is very easy and natural if you know Mathematica: it's designed to do this kind of manipulation. Making the Mathematica side responsible for models seems to be a good way to go; one advantage is that it's easy to add specialized models as needed for a particular analysis: just define them in your Mathematica code before importing the "netlist". My gEDAmath.m package defines helper functions for model construction, so models tend to be just a line or two of code. But in Sage, at least, expanding functions into lists of equations doesn't appear to be easy or natural. The attempt pushes you into the ill-documented borderland between Python and Maxima. No doubt it's possible if you're an expert, but we failed at it. I suppose another way to go would be to make gnetlist responsible for model expansion, but that would be less flexible, I think. Perhaps Sage isn't the right math system and another system would be better. If anyone can recommend a system and help with the programming on that side (especially in defining what the "netlist" should look like), the gnetlist side is something that's pretty easy for me. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ j...@noqsi.com ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Thursday 08 April 2010, Kai-Martin Knaak wrote: > This is one of the strange consequences of the common law > system. In the rest of the world, where civil law is > applied, ignorance of the delinquent does not diminish the > forfeit. > It isn't law that you could be ignorant of. It's a "work". If you know about the "work" and do something like it, they have a strong case that yours is influenced by theirs. If you don't know about something, you can't copy it, and you are in a stronger position to defend that you did it independently. It's not just patents .. It applies wherever there is "intelectual property", such as trade secrets. Signing a non-disclosure agreement is dangerous in a similar way. The EDA business is small and tight. If any EDA company were to attack gEDA, the biggest impact would be in publicity (negative for them, positive for us). I don't feel threatened. Hey, Synopsys, come and get me. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Wed, 07 Apr 2010 14:58:04 -0400, DJ Delorie wrote: > For starters, archived proof that you knew of the existence of a patent > automatically triples any damages you may have to pay. ^^^ This is one of the strange consequences of the common law system. In the rest of the world, where civil law is applied, ignorance of the delinquent does not diminish the forfeit. ---<)kaimartin(>--- -- Kai-Martin Knaak tel: +49-511-762-2895 Universität Hannover, Inst. für Quantenoptik fax: +49-511-762-2211 Welfengarten 1, 30167 Hannover http://www.iqo.uni-hannover.de GPG key:http://pgp.mit.edu:11371/pks/lookup?search=Knaak+kmk&op=get ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
John Doty wrote: > > On Apr 7, 2010, at 11:54 AM, al davis wrote: > >> On Wednesday 07 April 2010, Stuart Brorson wrote: Do you foresee any other difficulties? ... aside from simulating a hydraulic circuit with spice or generating a layout. >>> >>> Actually, my first thought was: What kinds of simulations >>> (if any) does one do in hydraulics? Are there any standard >>> simulators? If so, generating a netlist to feed to such a >>> simulator might be an interesting hobby project. >> >> If simulation means Spice to you, you are 20 years behind. > > Unless you have deep pockets (and even for some who do), SPICE is today's > simulator. I know you don't like this, but it's the truth. > >> >> Looking to the past ... Simulations of things like this were >> (and are) often done on a proprietary commercial simulator >> "Saber", using a proprietary modeling language "Mast". >> Matlab/Simulink is also popular (and proprietary). >> >> Looking forward ... Things like this can be done very well in >> Verilog-AMS, which has a published standard, cleaner syntax, and >> several commercial implementations. Many users of Saber and >> Mast are switching over. Gnucap provides partial support for >> Verilog-AMS, and is working on more complete support. > > But that's tomorrow. > > Another approach you'll hate is to use the symbolic capabilities of a > computer algebra system to analyze a design. See > http://www.noqsi.com/images/pareg.nb.pdf for an example hot off the press. > Unfortunately, the free software offerings don't seem to be up to this yet. > Fortunately, Mathematica isn't as pricey as fancy EDA tools, and gEDA can > feed it just fine. > Umm, now that you mention Mathematica: Do you know of a way of feeding from gEDA to Open Source computer math packages like octave or scilab? Not that i'd currently feel a personal need of it, but i'm curious. Such information often came in handy when i expected it the least beforehand... Greets, Florian ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Hi Tom, I like the style of the symbols, great work. I will have a look at the company hydraulics symbol lib today and see what else comes up. The company I work uses a lot of hydraulic drive systems. BTW: I have forked your repo to have a local version to work on and work with myself. Watch your forkqueue :-) Kind regards, Bert Timmerman. > -Original Message- > From: geda-user-boun...@moria.seul.org > [mailto:geda-user-boun...@moria.seul.org] On Behalf Of Tom Hawkins > Sent: Thursday, April 08, 2010 4:13 AM > To: gEDA user mailing list > Subject: Re: gEDA-user: hydraulic symbols and schematics > > Thanks for all the input. Here's the little hydraulic symbol > library I started: > > http://tomahawkins.org/gschem-hydraulics.png > http://github.com/tomahawkins/hydraulics > > A bit later I'll looking into path fills, and after that, > netlisting this into something that can be simulated. > > Thanks for your help. > > -Tom > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Thanks for all the input. Here's the little hydraulic symbol library I started: http://tomahawkins.org/gschem-hydraulics.png http://github.com/tomahawkins/hydraulics A bit later I'll looking into path fills, and after that, netlisting this into something that can be simulated. Thanks for your help. -Tom ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On 07/04/2010, Dave McGuire wrote: > On Apr 7, 2010, at 3:14 PM, al davis wrote: >>>Ok, that's fine by me, as it's your list. But could you >>> explain how it could be dangerous? That suggestion sounds >>> quite ludicrous to me. >> >> In general, it really does present a huge legal risk, so I agree >> with the policy. > >I will respect the policy and I apologize for my comment to Bert. > I'm still having a really hard time with the notion of mentioning the > existence of a patent constituting a legal risk. > > -Dave Many of us still try to wrap our heads around things like that. This article may be of help http://news.swpat.org/2010/03/transcript-tridgell-patents/ cheers. -- Adrian. http://elesquinazotango.com.ar http://www.noalcodigodescioli.blogspot.com/ ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Apr 7, 2010, at 3:14 PM, al davis wrote: Ok, that's fine by me, as it's your list. But could you explain how it could be dangerous? That suggestion sounds quite ludicrous to me. In general, it really does present a huge legal risk, so I agree with the policy. I will respect the policy and I apologize for my comment to Bert. I'm still having a really hard time with the notion of mentioning the existence of a patent constituting a legal risk. -Dave -- Dave McGuire Port Charlotte, FL ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
You might find University of South Carolina 's VTB (Virtual Test Bench) software useful. It is free to download (but seems to be closed source -- I couldn't find any details on the license). [1]http://vtb.engr.sc.edu/vtbwebsite/#/Overview It's intended for doing multidisciplinary simulations involving fluid flow, electronics, logic, microcontrollers and so on, with different solvers being used for different types of components in the simulation. You can add your own solver, or write your own device primitives using existing solvers. It includes components representing pumps, valves, digital logic, motors, space vector modulation algorithms, vehicles, math functions, etc. The interface is quite nice to use, too. As for the gschem / spice route - It occurs to me that if you want to simulate hydraulic systems, you'll have to keep track of both pressure and temperature of the fluid in the lines. If each hydraulic line is represented by a single line in gschem, the netlister should convert it into two different nets in the spice simulation - one for pressure and one for temperature in that line. Also, take a good look at gnucap; it also has the flexibility of adding your own device primitives, which could be very useful for fluid systems. I haven't tried it, but a simple primitive of the form "pressure drop = 0.5 * Cv * flow^2" is probably much easier to implement in gnucap than in spice. __ Looking for the perfect gift?[2] Give the gift of Flickr! References 1. http://vtb.engr.sc.edu/vtbwebsite/#/Overview 2. http://www.flickr.com/gift/ ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Hi Tom, I'm a mechanical engineer (BSc) with an electrical background (Technical College). I have thought of and made a small start for non-electrical symbols for Piping & Instrumentation Diagrams, with hydraulics and pneumatical symbols to follow (http://github.com/bert/gschem-symbols/tree/master/piping/). Another use for gschem, netlist and friends could be the simulation of distribution networks of natural gas or tap water, maybe even simulation of drainage systems: ditches, canals and/or large water ways. It's just a matter entering a schematic representation for connectivity (nets), adding the right attributes and invoking a scheme backend with netlist to do your preprocessing and solver stuff (this is the real challenge, not the schematics). Just my EUR 0.02 Kind regards, Bert Timmerman. > -Original Message- > From: geda-user-boun...@moria.seul.org > [mailto:geda-user-boun...@moria.seul.org] On Behalf Of Tom Hawkins > Sent: Wednesday, April 07, 2010 7:41 PM > To: gEDA user mailing list > Subject: Re: gEDA-user: hydraulic symbols and schematics > > On Wed, Apr 7, 2010 at 12:02 PM, Stuart Brorson > wrote: > > Hi -- > > > >> Obviously gschem is intended for electric circuits, but has anyone > >> used it for hydraulic schematics? The hydraulics industry has > >> defined a fairly rich schematic language [1][2] for describing > >> hydraulic and pneumatic systems. > >> > >> I didn't find a gschem hydraulic symbol library, so I'm > attempting to > >> build one. My first stumbling block is the use of filled and > >> non-filled triangles, which differentiate hydraulic pumps from > >> pneumatic compressors. Is it possible to draw filled triangles or > >> polygons with gschem? > > > > I don't think vanilla gschem currently supports filled > regions. But > > this is a frequently requested feature, and the folks in > Cambridge may > > have coded up a solution based upon the whizzy graphic work > they have > > done. > > Well it appears to fill circles and boxes just fine. Maybe > it just needs the ability to handle arbitrary polygons. > > > > >> Do you foresee any other difficulties? ... aside from > simulating a > >> hydraulic circuit with spice or generating a layout. > > > > Actually, my first thought was: What kinds of simulations (if any) > > does one do in hydraulics? Are there any standard > simulators? If so, > > generating a netlist to feed to such a simulator might be an > > interesting hobby project. > > We use Easy5 and Simulink. But Easy5 doesn't run on Linux > and both tools are very clunky and neither have a standard > format. This year I plan to build some tools in this space. > It would be cool to netlist a hydraulic design out of gschem > and simulate it with other stuff like embedded software and > vehicle dynamics. > > If you look at some hydraulic schematics, you'll see a rich > duality between electric and hydraulic circuits. For > example, the pressure drop across an orifice is analogous to > the voltage drop across a resistor. Hydraulic power is > pressure * flow (i.e. V * I). > > > > >> (BTW at Eaton, we have a history of bending EDA tools for our > >> purposes. We used GTKWave to view and analyze vehicle data in > >> realtime.) > > > > Awesome! How did you get the real time info into GTKWave? IIRC, it > > only reads .vsd (and other simulation) files. > > We extract vehicle data via. a CAN bus. We then convert the > streaming CSV data into VCD and pipe this into GTKWave. The > command line reads: > > $ readCAN | tovcd - | shmidcat | gtkwave -v -I my.sav > > We put a laptop in the passenger seat when we take our test > vehicles out for a drive. With the analog features of > GTKWave, you can see all the vehicle data varying in > realtime. It's really cool. > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Wednesday 07 April 2010, Dave McGuire wrote: >Ok, that's fine by me, as it's your list. But could you > explain how it could be dangerous? That suggestion sounds > quite ludicrous to me. In general, it really does present a huge legal risk, so I agree with the policy. In this case, the patent is so old that it has gone into the public domain long ago. A long time ago, all this stuff we consider to be so basic was new. The concept of duality between different types of "circuits" is well known, and taught in undergraduate engineering courses. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Tom, > I didn't find a gschem hydraulic symbol library, so I'm attempting to > build one. My first stumbling block is the use of filled and > non-filled triangles, which differentiate hydraulic pumps from > pneumatic compressors. Is it possible to draw filled triangles or > polygons with gschem? See this: http://geda.seul.org/wiki/geda:file_format_spec?s=svg#path Currently only available when using your favourite text editor _and_ a recent gschem for printing. Please first try to print the given example symbols, using the component dialog see under "Basic Device" for these symbols: npn-1.sym, npn-2.sym, etc. Bas -- ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Apr 7, 2010, at 2:58 PM, DJ Delorie wrote: Ok, that's fine by me, as it's your list. But could you explain how it could be dangerous? That suggestion sounds quite ludicrous to me. For starters, archived proof that you knew of the existence of a patent automatically triples any damages you may have to pay. Ahh. I tend to at least *try* to avoid patent infringement myself, so I never thought of that. Thanks for the example. -Dave -- Dave McGuire Port Charlotte, FL ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
>Ok, that's fine by me, as it's your list. But could you explain > how it could be dangerous? That suggestion sounds quite ludicrous > to me. For starters, archived proof that you knew of the existence of a patent automatically triples any damages you may have to pay. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Apr 7, 2010, at 2:51 PM, Ales Hvezda wrote: Do not discuss patents here please ! This is highly contageous and attracts law suits. Without the mentioning of patents the general idea would have come across as well. Oh good heavens. Mentioning the existence of a patent, and suggesting it as good reading because it contains interesting and geeky science stuff, attracts LAWSUITS? No really. Please do not post or discuss patents on any gEDA mailing list. Ok, that's fine by me, as it's your list. But could you explain how it could be dangerous? That suggestion sounds quite ludicrous to me. -Dave -- Dave McGuire Port Charlotte, FL ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Wed, Apr 7, 2010 at 2:49 PM, Dave McGuire wrote: > On Apr 7, 2010, at 2:46 PM, Bert Timmerman wrote: >> >> Do not discuss patents here please ! >> >> This is highly contageous and attracts law suits. >> >> Without the mentioning of patents the general idea would have come across >> as >> well. > > Oh good heavens. Mentioning the existence of a patent, and suggesting it > as good reading because it contains interesting and geeky science stuff, > attracts LAWSUITS? No really. Please do not post or discuss patents on any gEDA mailing list. -Ales -- Ales Hvezda ahve...@computer.org ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Wednesday 07 April 2010, Bert Timmerman wrote: > Do not discuss patents here please ! Did you notice the date? (1934) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
>Oh good heavens. Mentioning the existence of a patent, and > suggesting it as good reading because it contains interesting and > geeky science stuff, attracts LAWSUITS? Regardless, I would also say "do not discuss patents here", for various (legal and otherwise) reasons. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Apr 7, 2010, at 2:46 PM, Bert Timmerman wrote: Do not discuss patents here please ! This is highly contageous and attracts law suits. Without the mentioning of patents the general idea would have come across as well. Oh good heavens. Mentioning the existence of a patent, and suggesting it as good reading because it contains interesting and geeky science stuff, attracts LAWSUITS? Not enough coffee this morning Bert? -Dave -- Dave McGuire Port Charlotte, FL ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Hi Bob, Do not discuss patents here please ! This is highly contageous and attracts law suits. Without the mentioning of patents the general idea would have come across as well. Kind regards, Bert Timmerman. > -Original Message- > From: geda-user-boun...@moria.seul.org > [mailto:geda-user-boun...@moria.seul.org] On Behalf Of Bob Paddock > Sent: Wednesday, April 07, 2010 8:10 PM > To: gEDA user mailing list > Subject: Re: gEDA-user: hydraulic symbols and schematics > > > If you look at some hydraulic schematics, you'll see a rich duality > > between electric and hydraulic circuits. For example, the pressure > > drop across an orifice is analogous to the voltage drop across a > > resistor. Hydraulic power is pressure * flow (i.e. V * I). > > http://www.unusualresearch.com/Pump/bellocq.htm > > US Patent: 1,941,593 01/02/1934 "PUMPING" [This patent is > interesting in that it shows the plumbing equivalent to > resonance circuits, high pass, low pass, and band pass filters.] > > http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&ad jacent=true&locale=en_EP&FT=D&date=19340102&CC=US&NR=1941593A&KC=A > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Apr 7, 2010, at 11:54 AM, al davis wrote: > On Wednesday 07 April 2010, Stuart Brorson wrote: >>> Do you foresee any other difficulties? ... aside from >>> simulating a hydraulic circuit with spice or generating a >>> layout. >> >> Actually, my first thought was: What kinds of simulations >> (if any) does one do in hydraulics? Are there any standard >> simulators? If so, generating a netlist to feed to such a >> simulator might be an interesting hobby project. > > If simulation means Spice to you, you are 20 years behind. Unless you have deep pockets (and even for some who do), SPICE is today's simulator. I know you don't like this, but it's the truth. > > Looking to the past ... Simulations of things like this were > (and are) often done on a proprietary commercial simulator > "Saber", using a proprietary modeling language "Mast". > Matlab/Simulink is also popular (and proprietary). > > Looking forward ... Things like this can be done very well in > Verilog-AMS, which has a published standard, cleaner syntax, and > several commercial implementations. Many users of Saber and > Mast are switching over. Gnucap provides partial support for > Verilog-AMS, and is working on more complete support. But that's tomorrow. Another approach you'll hate is to use the symbolic capabilities of a computer algebra system to analyze a design. See http://www.noqsi.com/images/pareg.nb.pdf for an example hot off the press. Unfortunately, the free software offerings don't seem to be up to this yet. Fortunately, Mathematica isn't as pricey as fancy EDA tools, and gEDA can feed it just fine. John Doty Noqsi Aerospace, Ltd. http://www.noqsi.com/ j...@noqsi.com ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
> If you look at some hydraulic schematics, you'll see a rich duality > between electric and hydraulic circuits. For example, the pressure > drop across an orifice is analogous to the voltage drop across a > resistor. Hydraulic power is pressure * flow (i.e. V * I). http://www.unusualresearch.com/Pump/bellocq.htm US Patent: 1,941,593 01/02/1934 "PUMPING" [This patent is interesting in that it shows the plumbing equivalent to resonance circuits, high pass, low pass, and band pass filters.] http://v3.espacenet.com/publicationDetails/biblio?DB=EPODOC&adjacent=true&locale=en_EP&FT=D&date=19340102&CC=US&NR=1941593A&KC=A ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Wednesday 07 April 2010, Stuart Brorson wrote: > > Do you foresee any other difficulties? ... aside from > > simulating a hydraulic circuit with spice or generating a > > layout. > > Actually, my first thought was: What kinds of simulations > (if any) does one do in hydraulics? Are there any standard > simulators? If so, generating a netlist to feed to such a > simulator might be an interesting hobby project. If simulation means Spice to you, you are 20 years behind. Looking to the past ... Simulations of things like this were (and are) often done on a proprietary commercial simulator "Saber", using a proprietary modeling language "Mast". Matlab/Simulink is also popular (and proprietary). Looking forward ... Things like this can be done very well in Verilog-AMS, which has a published standard, cleaner syntax, and several commercial implementations. Many users of Saber and Mast are switching over. Gnucap provides partial support for Verilog-AMS, and is working on more complete support. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
On Wed, Apr 7, 2010 at 12:02 PM, Stuart Brorson wrote: > Hi -- > >> Obviously gschem is intended for electric circuits, but has anyone >> used it for hydraulic schematics? The hydraulics industry has defined >> a fairly rich schematic language [1][2] for describing hydraulic and >> pneumatic systems. >> >> I didn't find a gschem hydraulic symbol library, so I'm attempting to >> build one. My first stumbling block is the use of filled and >> non-filled triangles, which differentiate hydraulic pumps from >> pneumatic compressors. Is it possible to draw filled triangles or >> polygons with gschem? > > I don't think vanilla gschem currently supports filled regions. But > this is a frequently requested feature, and the folks in Cambridge may > have coded up a solution based upon the whizzy graphic work they have > done. Well it appears to fill circles and boxes just fine. Maybe it just needs the ability to handle arbitrary polygons. > >> Do you foresee any other difficulties? ... aside from simulating a >> hydraulic circuit with spice or generating a layout. > > Actually, my first thought was: What kinds of simulations (if any) > does one do in hydraulics? Are there any standard simulators? If so, > generating a netlist to feed to such a simulator might be an > interesting hobby project. We use Easy5 and Simulink. But Easy5 doesn't run on Linux and both tools are very clunky and neither have a standard format. This year I plan to build some tools in this space. It would be cool to netlist a hydraulic design out of gschem and simulate it with other stuff like embedded software and vehicle dynamics. If you look at some hydraulic schematics, you'll see a rich duality between electric and hydraulic circuits. For example, the pressure drop across an orifice is analogous to the voltage drop across a resistor. Hydraulic power is pressure * flow (i.e. V * I). > >> (BTW at Eaton, we have a history of bending EDA tools for our >> purposes. We used GTKWave to view and analyze vehicle data in >> realtime.) > > Awesome! How did you get the real time info into GTKWave? IIRC, it > only reads .vsd (and other simulation) files. We extract vehicle data via. a CAN bus. We then convert the streaming CSV data into VCD and pipe this into GTKWave. The command line reads: $ readCAN | tovcd - | shmidcat | gtkwave -v -I my.sav We put a laptop in the passenger seat when we take our test vehicles out for a drive. With the analog features of GTKWave, you can see all the vehicle data varying in realtime. It's really cool. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: hydraulic symbols and schematics
Hi -- Obviously gschem is intended for electric circuits, but has anyone used it for hydraulic schematics? The hydraulics industry has defined a fairly rich schematic language [1][2] for describing hydraulic and pneumatic systems. I didn't find a gschem hydraulic symbol library, so I'm attempting to build one. My first stumbling block is the use of filled and non-filled triangles, which differentiate hydraulic pumps from pneumatic compressors. Is it possible to draw filled triangles or polygons with gschem? I don't think vanilla gschem currently supports filled regions. But this is a frequently requested feature, and the folks in Cambridge may have coded up a solution based upon the whizzy graphic work they have done. Do you foresee any other difficulties? ... aside from simulating a hydraulic circuit with spice or generating a layout. Actually, my first thought was: What kinds of simulations (if any) does one do in hydraulics? Are there any standard simulators? If so, generating a netlist to feed to such a simulator might be an interesting hobby project. (BTW at Eaton, we have a history of bending EDA tools for our purposes. We used GTKWave to view and analyze vehicle data in realtime.) Awesome! How did you get the real time info into GTKWave? IIRC, it only reads .vsd (and other simulation) files. Stuart ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: hydraulic symbols and schematics
Hi, Obviously gschem is intended for electric circuits, but has anyone used it for hydraulic schematics? The hydraulics industry has defined a fairly rich schematic language [1][2] for describing hydraulic and pneumatic systems. I didn't find a gschem hydraulic symbol library, so I'm attempting to build one. My first stumbling block is the use of filled and non-filled triangles, which differentiate hydraulic pumps from pneumatic compressors. Is it possible to draw filled triangles or polygons with gschem? Do you foresee any other difficulties? ... aside from simulating a hydraulic circuit with spice or generating a layout. (BTW at Eaton, we have a history of bending EDA tools for our purposes. We used GTKWave to view and analyze vehicle data in realtime.) Thanks. -Tom [1] http://www.hydraulicspneumatics.com/200/eBooks/Article/True/32028/ [2] http://www.airlinehyd.com/KnowledgeCenter/Symbols.asp ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
