Re: gEDA-user: NE 555 and simulation issue
On Mon, 08 Mar 2010 11:18:10 -0500, al davis wrote: > Unfortunately, progress has > been hampered by a development team that is far too small, IMHO, a big obstacle to widespread use of gnucap in geda related projects is missing integration with gschem. A feature to easily export a subset of the current circuit to gnucap would is critical as it significantly lowers the entry barrier. As long as this level of ease is not reached, ltspice is the most rational choice to get the job done for simple circuits. The other big issue I see, is a lack of default models for the most common analog components. As with ease of use, ltspice wins hands down at this discipline. I'd be more than happy to see progress with both these issues. > and not much open community involvement. community involvement will develop if the tool gets used by a critical amount of users. No users, no community. So, if the gnucap project is to gain momentum, it needs to concentrate on usability first. ---<(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: NE 555 and simulation issue
On Tuesday 02 March 2010, Peter Clifton wrote: > Gnucap is another advanced simulation environment which might > be interesting. It is different to spice, but can accept > spice syntax and models etc.. Again, milage will vary as to > how well it works with a given model - and it is by no means > a drop in replacement for spice, some things are just done > differently. > > Al might chime in and give more info if I've got anything > wrong here, as I'm certainly not an expert - and Al ought to > know, since he writes Gnucap. Gnucap is not designed as a drop-in replacement of Spice. That would be a waste of time. Rather, it is designed as a followup to Spice, bringing free simulation up to date, and hopefully taking the lead. In commercial simulators, there are lots of them that are just Spice. In that regard, NGspice is our spice. Then there are those that move beyond, in many ways. They sell for a much higher price than any Spice. This is the "mixed signal", "fast spice" and lots of others. The only reason they haven't completely replaced Spice is MARKETING. They can sell a Spice cheap, and make big bucks on the new one. Gnucap is designed with full knowledge of Spice and others, to address the big shortcomings of Spice, and move on. I am referring to the real issues here, not the ones that can be easily fixed. Unfortunately, progress has been hampered by a development team that is far too small, and not much open community involvement. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
Hi there, I've recently stumbled upon this: http://geekwentfreak.wordpress.com/2009/12/11/spice-gschem-gnetlist-gnucap-gwave-gspiceui-linux/ Hope it helps, Denis Am 02.03.2010, 12:30 Uhr, schrieb W.H. Kalpa Pathum : Hi, I'm an electrical engineering student and I'm new to gEDA. I'm given a project and I've got several circuits. I want to simulate rather than soldering them all actually so that I can choose the best circuit. I use Fedora 12 and I have installed ng-spice also. My circuit has a NE555 timer and I couldn't find a symbol for NE555 in gEDA Schemetic Editor. So how can I find a circuit. Next is, I designed a simple circuit with a power source, LED and a resistor. I wanted to simulate the circuit and see the voltage across the resistor. But I couldn't find how to do it. So if you can provide me with a simple step by step guide on how to do this that would be much appreciated. Thanks in advance. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Wed, Mar 3, 2010 at 1:17 AM, Denis Grelich wrote: > Hi there, > > I've recently stumbled upon this: > > http://geekwentfreak.wordpress.com/2009/12/11/spice-gschem-gnetlist-gnucap-gwave-gspiceui-linux/ > > Hope it helps, wow that was really usefull. Thanks > > Denis > > > Am 02.03.2010, 12:30 Uhr, schrieb W.H. Kalpa Pathum : > >> Hi, >> >> I'm an electrical engineering student and I'm new to gEDA. I'm given a >> project and I've got several circuits. I want to simulate rather than >> soldering them all actually so that I can choose the best circuit. I >> use Fedora 12 and I have installed ng-spice also. >> >> My circuit has a NE555 timer and I couldn't find a symbol for NE555 in >> gEDA Schemetic Editor. So how can I find a circuit. >> >> Next is, I designed a simple circuit with a power source, LED and a >> resistor. I wanted to simulate the circuit and see the voltage across >> the resistor. But I couldn't find how to do it. So if you can provide >> me with a simple step by step guide on how to do this that would be >> much appreciated. >> >> Thanks in advance. >> > > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > -- W.H.Kalpa Pathum ... http://kalpapathum.blogspot.com http://thiraya.wordpress.com http://www.twitter.com/callkalpa ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Tuesday 02 March 2010, Geoff Swan wrote: > It has been my experience that circuit modeling tools > although useful are not able to negate the need to > understand the low level principles of the underlying > circuit. The better you understand the physics of what is > going on the more value you will get from your circuit > modelling. > That is one of the reasons I often recommend using simple models of things instead of the ones you can download. It seems this is not taught in schools like it should be. Instead, they teach "professional" (ha) tools, often without knowing what professionals use or how they use them. Simulation is very useful as a study aid to help understand the low level principles. Unfortunately, very few texts and very few professors use it this way. They teach simulation strictly for validation, not for exploration, and don't even do a good job at that. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
>Seriously - simulating for things like this is not going to be the best >way to design circuits.. physical variation between parts, and >discrepancies between the model and reality, plus limited choices of >real-world resistor values will mean it is pretty pointless trying to >get any more accurate than what I've just calculated above. It has been my experience that circuit modeling tools although useful are not able to negate the need to understand the low level principles of the underlying circuit. The better you understand the physics of what is going on the more value you will get from your circuit modelling. All the best, Geoff. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
Hi there, I've recently stumbled upon this: http://geekwentfreak.wordpress.com/2009/12/11/spice-gschem-gnetlist-gnucap-gwave-gspiceui-linux/ Hope it helps, Denis Am 02.03.2010, 12:30 Uhr, schrieb W.H. Kalpa Pathum : Hi, I'm an electrical engineering student and I'm new to gEDA. I'm given a project and I've got several circuits. I want to simulate rather than soldering them all actually so that I can choose the best circuit. I use Fedora 12 and I have installed ng-spice also. My circuit has a NE555 timer and I couldn't find a symbol for NE555 in gEDA Schemetic Editor. So how can I find a circuit. Next is, I designed a simple circuit with a power source, LED and a resistor. I wanted to simulate the circuit and see the voltage across the resistor. But I couldn't find how to do it. So if you can provide me with a simple step by step guide on how to do this that would be much appreciated. Thanks in advance. ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Tue, Mar 2, 2010 at 10:09 PM, Peter Clifton wrote: > On Tue, 2010-03-02 at 21:46 +0530, W.H. Kalpa Pathum wrote: >> > >> > SPICE 3f5 is the latest Berkeley release, and this is (if I recall >> > correctly) the release from which ng-spice is derived. 3f5 does build >> > under >> > Linux, I think. >> >> that's news, thanks :-) >> > >> > But regardless, ng-spice is pretty much "real" SPICE, so you're on the >> > right track! Lots of companies have grabbed the free SPICE, made >> > vendor-specific enhancements, and released it as a binary-only product >> > (usually for one specific company's rickety, proprietary operating system) >> > and often not for free. This doesn't mean "SPICE isn't free". ;) > > Unfortunately, most spice course I've seen use P-Spice, as the de-facto > standard. The models may not be completely compatible with ng-spice, so > your mileage will vary. > > Gnucap is another advanced simulation environment which might be > interesting. It is different to spice, but can accept spice syntax and > models etc.. Again, milage will vary as to how well it works with a > given model - and it is by no means a drop in replacement for spice, > some things are just done differently. > > Al might chime in and give more info if I've got anything wrong here, as > I'm certainly not an expert - and Al ought to know, since he writes > Gnucap. > yeah but I hope to read some extra and be with ng-spice or gnucap. Thanks > -- > Peter Clifton > > Electrical Engineering Division, > Engineering Department, > University of Cambridge, > 9, JJ Thomson Avenue, > Cambridge > CB3 0FA > > Tel: +44 (0)7729 980173 - (No signal in the lab!) > > > > ___ > geda-user mailing list > geda-user@moria.seul.org > http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > -- W.H.Kalpa Pathum ... http://kalpapathum.blogspot.com http://thiraya.wordpress.com http://www.twitter.com/callkalpa ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Tue, 2010-03-02 at 21:46 +0530, W.H. Kalpa Pathum wrote: > > > > SPICE 3f5 is the latest Berkeley release, and this is (if I recall > > correctly) the release from which ng-spice is derived. 3f5 does build under > > Linux, I think. > > that's news, thanks :-) > > > > But regardless, ng-spice is pretty much "real" SPICE, so you're on the > > right track! Lots of companies have grabbed the free SPICE, made > > vendor-specific enhancements, and released it as a binary-only product > > (usually for one specific company's rickety, proprietary operating system) > > and often not for free. This doesn't mean "SPICE isn't free". ;) Unfortunately, most spice course I've seen use P-Spice, as the de-facto standard. The models may not be completely compatible with ng-spice, so your mileage will vary. Gnucap is another advanced simulation environment which might be interesting. It is different to spice, but can accept spice syntax and models etc.. Again, milage will vary as to how well it works with a given model - and it is by no means a drop in replacement for spice, some things are just done differently. Al might chime in and give more info if I've got anything wrong here, as I'm certainly not an expert - and Al ought to know, since he writes Gnucap. -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Tue, Mar 2, 2010 at 9:43 PM, Dave McGuire wrote: > On Mar 2, 2010, at 11:08 AM, W.H. Kalpa Pathum wrote: > > For simple circuit simulation, you can use Ktechlab (directly su -c > 'yum install -y ktechlab'). > It's not very fast, not very accurate, but very graphic and simple. It > may fits for your purpose... > wow this app suits my requirement. Thanks Thanks for all you foryour quick and friendly responses. KTechlab was more that enough for my requirement. It seems that the other apps including gEDA are move advanced and need a lot of effort in learning. We will be having a module on circuit simulation in near future. They use Spice and I hope to use ng-spice as I'm much more interested in FOSS. >>> >>> Urr? SPICE has always been freely available. I remember downloading it >>> and building it on a VAX easily twenty years ago. >>> >> But they don't offer a linux version I guess. > > I'm pretty sure I built it under Ultrix, which is an early BSD UNIX > derivative. I know I built a FORTRAN version under VMS, but I'm pretty sure > I built one on Ultrix. > > SPICE 3f5 is the latest Berkeley release, and this is (if I recall > correctly) the release from which ng-spice is derived. 3f5 does build under > Linux, I think. that's news, thanks :-) > > But regardless, ng-spice is pretty much "real" SPICE, so you're on the > right track! Lots of companies have grabbed the free SPICE, made > vendor-specific enhancements, and released it as a binary-only product > (usually for one specific company's rickety, proprietary operating system) > and often not for free. This doesn't mean "SPICE isn't free". ;) > > -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 > -- W.H.Kalpa Pathum ... http://kalpapathum.blogspot.com http://thiraya.wordpress.com http://www.twitter.com/callkalpa ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Mar 2, 2010, at 11:08 AM, W.H. Kalpa Pathum wrote: For simple circuit simulation, you can use Ktechlab (directly su -c 'yum install -y ktechlab'). It's not very fast, not very accurate, but very graphic and simple. It may fits for your purpose... wow this app suits my requirement. Thanks Thanks for all you foryour quick and friendly responses. KTechlab was more that enough for my requirement. It seems that the other apps including gEDA are move advanced and need a lot of effort in learning. We will be having a module on circuit simulation in near future. They use Spice and I hope to use ng-spice as I'm much more interested in FOSS. Urr? SPICE has always been freely available. I remember downloading it and building it on a VAX easily twenty years ago. But they don't offer a linux version I guess. I'm pretty sure I built it under Ultrix, which is an early BSD UNIX derivative. I know I built a FORTRAN version under VMS, but I'm pretty sure I built one on Ultrix. SPICE 3f5 is the latest Berkeley release, and this is (if I recall correctly) the release from which ng-spice is derived. 3f5 does build under Linux, I think. But regardless, ng-spice is pretty much "real" SPICE, so you're on the right track! Lots of companies have grabbed the free SPICE, made vendor-specific enhancements, and released it as a binary-only product (usually for one specific company's rickety, proprietary operating system) and often not for free. This doesn't mean "SPICE isn't free". ;) -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: NE 555 and simulation issue
On Tue, Mar 2, 2010 at 9:32 PM, Dave McGuire wrote: > On Mar 2, 2010, at 10:57 AM, W.H. Kalpa Pathum wrote: >>> >>> For simple circuit simulation, you can use Ktechlab (directly su -c >>> 'yum install -y ktechlab'). >>> It's not very fast, not very accurate, but very graphic and simple. It >>> may fits for your purpose... >>> >> >> wow this app suits my requirement. Thanks >> >> Thanks for all you foryour quick and friendly responses. KTechlab was >> more that enough for my requirement. It seems that the other apps >> including gEDA are move advanced and need a lot of effort in learning. >> >> We will be having a module on circuit simulation in near future. They >> use Spice and I hope to use ng-spice as I'm much more interested in >> FOSS. > > Urr? SPICE has always been freely available. I remember downloading it > and building it on a VAX easily twenty years ago. > But they don't offer a linux version I guess. > -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 > -- W.H.Kalpa Pathum ... http://kalpapathum.blogspot.com http://thiraya.wordpress.com http://www.twitter.com/callkalpa ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
On Mar 2, 2010, at 10:57 AM, W.H. Kalpa Pathum wrote: For simple circuit simulation, you can use Ktechlab (directly su -c 'yum install -y ktechlab'). It's not very fast, not very accurate, but very graphic and simple. It may fits for your purpose... wow this app suits my requirement. Thanks Thanks for all you foryour quick and friendly responses. KTechlab was more that enough for my requirement. It seems that the other apps including gEDA are move advanced and need a lot of effort in learning. We will be having a module on circuit simulation in near future. They use Spice and I hope to use ng-spice as I'm much more interested in FOSS. Urr? SPICE has always been freely available. I remember downloading it and building it on a VAX easily twenty years ago. -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: NE 555 and simulation issue
2010/3/2 Miguel Sánchez de León Peque : > I forgot it: as you are just interested in simulation, there's another > program, called Qucs (also available in the official Fedora repos), > more accurate and "proffesional" than Ktechlab, although it is more > difficult to learn (and let me say it's uglier too ;-) ). And I think > there's no 555 device defined in Qucs, so you'll need to design it or > find it somewhere. > PS: you do have a 555 defined in Ktechlab > > 2010/3/2 W.H. Kalpa Pathum <[1]callka...@gmail.com> > > Hi, > I'm an electrical engineering student and I'm new to gEDA. I'm given > a > project and I've got several circuits. I want to simulate rather > than > soldering them all actually so that I can choose the best circuit. I > use Fedora 12 and I have installed ng-spice also. > My circuit has a NE555 timer and I couldn't find a symbol for NE555 > in > gEDA Schemetic Editor. So how can I find a circuit. > Next is, I designed a simple circuit with a power source, LED and a > resistor. I wanted to simulate the circuit and see the voltage > across > the resistor. But I couldn't find how to do it. So if you can > provide > me with a simple step by step guide on how to do this that would be > much appreciated. > Thanks in advance. > -- > W.H.Kalpa Pathum > ... > [2]http://kalpapathum.blogspot.com > [3]http://thiraya.wordpress.com > [4]http://www.twitter.com/callkalpa > ... > ___ > geda-user mailing list > [5]geda-u...@moria.seul.org > [6]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > References > > 1. mailto:callka...@gmail.com > 2. http://kalpapathum.blogspot.com/ > 3. http://thiraya.wordpress.com/ > 4. http://www.twitter.com/callkalpa > 5. mailto:geda-user@moria.seul.org > 6. 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 > > -- W.H.Kalpa Pathum ... http://kalpapathum.blogspot.com http://thiraya.wordpress.com http://www.twitter.com/callkalpa ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
2010/3/2 Miguel Sánchez de León Peque : > For simple circuit simulation, you can use Ktechlab (directly su -c > 'yum install -y ktechlab'). > It's not very fast, not very accurate, but very graphic and simple. It > may fits for your purpose... > wow this app suits my requirement. Thanks Thanks for all you foryour quick and friendly responses. KTechlab was more that enough for my requirement. It seems that the other apps including gEDA are move advanced and need a lot of effort in learning. We will be having a module on circuit simulation in near future. They use Spice and I hope to use ng-spice as I'm much more interested in FOSS. So once again thanks for you all. > 2010/3/2 W.H. Kalpa Pathum <[1]callka...@gmail.com> > > Hi, > I'm an electrical engineering student and I'm new to gEDA. I'm given > a > project and I've got several circuits. I want to simulate rather > than > soldering them all actually so that I can choose the best circuit. I > use Fedora 12 and I have installed ng-spice also. > My circuit has a NE555 timer and I couldn't find a symbol for NE555 > in > gEDA Schemetic Editor. So how can I find a circuit. > Next is, I designed a simple circuit with a power source, LED and a > resistor. I wanted to simulate the circuit and see the voltage > across > the resistor. But I couldn't find how to do it. So if you can > provide > me with a simple step by step guide on how to do this that would be > much appreciated. > Thanks in advance. > -- > W.H.Kalpa Pathum > ... > [2]http://kalpapathum.blogspot.com > [3]http://thiraya.wordpress.com > [4]http://www.twitter.com/callkalpa > ... > > ___ > geda-user mailing list > [5]geda-u...@moria.seul.org > [6]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user > > References > > 1. mailto:callka...@gmail.com > 2. http://kalpapathum.blogspot.com/ > 3. http://thiraya.wordpress.com/ > 4. http://www.twitter.com/callkalpa > 5. mailto:geda-user@moria.seul.org > 6. 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 > > -- W.H.Kalpa Pathum ... http://kalpapathum.blogspot.com http://thiraya.wordpress.com http://www.twitter.com/callkalpa ... ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: NE 555 and simulation issue
I forgot it: as you are just interested in simulation, there's another program, called Qucs (also available in the official Fedora repos), more accurate and "proffesional" than Ktechlab, although it is more difficult to learn (and let me say it's uglier too ;-) ). And I think there's no 555 device defined in Qucs, so you'll need to design it or find it somewhere. PS: you do have a 555 defined in Ktechlab 2010/3/2 W.H. Kalpa Pathum <[1]callka...@gmail.com> Hi, I'm an electrical engineering student and I'm new to gEDA. I'm given a project and I've got several circuits. I want to simulate rather than soldering them all actually so that I can choose the best circuit. I use Fedora 12 and I have installed ng-spice also. My circuit has a NE555 timer and I couldn't find a symbol for NE555 in gEDA Schemetic Editor. So how can I find a circuit. Next is, I designed a simple circuit with a power source, LED and a resistor. I wanted to simulate the circuit and see the voltage across the resistor. But I couldn't find how to do it. So if you can provide me with a simple step by step guide on how to do this that would be much appreciated. Thanks in advance. -- W.H.Kalpa Pathum ... [2]http://kalpapathum.blogspot.com [3]http://thiraya.wordpress.com [4]http://www.twitter.com/callkalpa ... ___ geda-user mailing list [5]geda-u...@moria.seul.org [6]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user References 1. mailto:callka...@gmail.com 2. http://kalpapathum.blogspot.com/ 3. http://thiraya.wordpress.com/ 4. http://www.twitter.com/callkalpa 5. mailto:geda-user@moria.seul.org 6. 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: NE 555 and simulation issue
For simple circuit simulation, you can use Ktechlab (directly su -c 'yum install -y ktechlab'). It's not very fast, not very accurate, but very graphic and simple. It may fits for your purpose... 2010/3/2 W.H. Kalpa Pathum <[1]callka...@gmail.com> Hi, I'm an electrical engineering student and I'm new to gEDA. I'm given a project and I've got several circuits. I want to simulate rather than soldering them all actually so that I can choose the best circuit. I use Fedora 12 and I have installed ng-spice also. My circuit has a NE555 timer and I couldn't find a symbol for NE555 in gEDA Schemetic Editor. So how can I find a circuit. Next is, I designed a simple circuit with a power source, LED and a resistor. I wanted to simulate the circuit and see the voltage across the resistor. But I couldn't find how to do it. So if you can provide me with a simple step by step guide on how to do this that would be much appreciated. Thanks in advance. -- W.H.Kalpa Pathum ... [2]http://kalpapathum.blogspot.com [3]http://thiraya.wordpress.com [4]http://www.twitter.com/callkalpa ... ___ geda-user mailing list [5]geda-u...@moria.seul.org [6]http://www.seul.org/cgi-bin/mailman/listinfo/geda-user References 1. mailto:callka...@gmail.com 2. http://kalpapathum.blogspot.com/ 3. http://thiraya.wordpress.com/ 4. http://www.twitter.com/callkalpa 5. mailto:geda-user@moria.seul.org 6. 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: NE 555 and simulation issue
On Tue, 2010-03-02 at 17:00 +0530, W.H. Kalpa Pathum wrote: > Hi, > > I'm an electrical engineering student and I'm new to gEDA. I'm given a > project and I've got several circuits. I want to simulate rather than > soldering them all actually so that I can choose the best circuit. I > use Fedora 12 and I have installed ng-spice also. > > My circuit has a NE555 timer and I couldn't find a symbol for NE555 in > gEDA Schemetic Editor. So how can I find a circuit. I'm sure there will be one available somewhere - if not, you will have to create the symbol. (Creating symbols is a normal part of electronic design entry). Searching "555" in gschem's schematic window found an "LM555", which appears to have the same pinout. For future reference, you will find a useful resource of additional symbols here: www.gedasymbols.org As for a SPICE model (or any other simulator model), I've no idea where you would find that. Typically, these kinds of simple circuits ought to be designed / chosen using basic engineering approximations. The data-sheets tell you enough about how the device operates to be able to calculate the time periods it switches etc., calculate currents in components. Simulation should be a second stage - verification (if used at all), not a primary design tool. What kind of performance differences are you hoping to evaluate between the various circuits? So says the person looking for software to perform 3D finite volume / MoM, in a transient simulation for marine wave / float interaction - because I _can't_ build a huge experiment... we had this: http://www.tridentenergy.co.uk but it capsized :( > Next is, I designed a simple circuit with a power source, LED and a > resistor. I wanted to simulate the circuit and see the voltage across > the resistor. But I couldn't find how to do it. So if you can provide > me with a simple step by step guide on how to do this that would be > much appreciated. Unless you need the _exact_ operating point, just calculate it.. it is very easy. (And you'll probably find it difficult to get an LED spice model, and / or match the parameters to your particular device). I = (Vcc - Vf) / R Which, e.g. might be: Lets assume your LED has Fwd voltage drop of 2.7V (check the data-sheet), and wants a forward current of 15mA. The voltage across the LED is roughly fixed when the appropriate current is flowing, so subtract that from the supply voltage and get the voltage across the resistor. I'll assume your power source has negligible internal impedance, but if not - that needs to account for a part of R calculated below. 15mA = (5V - 2.7V) / R 15e-3A = 2.3 / R R = 153 Ohms Picking a near preferred value, let R=150 Ohms Current will then be (5-2.7) / 150 = 15.3 mA Seriously - simulating for things like this is not going to be the best way to design circuits.. physical variation between parts, and discrepancies between the model and reality, plus limited choices of real-world resistor values will mean it is pretty pointless trying to get any more accurate than what I've just calculated above. Best wishes, -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user