2009/7/27 Peter Jeremy <peterjer...@optushome.com.au>: > On 2009-Jul-26 11:07:49 -0700, William Stein <wst...@gmail.com> wrote: >>Hi Sage-Devel (in particular, people who know about electrical circuits), > > I'm not an EE but electronics is a hobby of mine. > >>I just happen to be meeting with an undergrad tomorrow at Univ. of >>Washington about him possibly working with me, and he mentioned that >>he wrote the following himself >> http://www.circuitengine.com/ > > As a standalone tool, it looks good. > >>He also said he may be interested in GPL'ing it, possibly getting >>something based on it into Sage (http://sagemath.org), etc. > > IMHO, there are two distinct issues to address: > 1) What benefits would Sage gain from having electronic circuit simulation > facilities built into it? > 2) Assuming Sage would benefit from circuit simulation, is CircuitEngine > a good choice? > > I don't think I'm in a position to offer useful input on the first question. > > As for the second, without denigrating the effort Kevin has put into it, > I don't think CircuitEngine has a particularly wide range of features. > IMHO, something like SPICE would bea much better choice. > > -- > Peter Jeremy > First I should state my first degree was in electrcal and electronic engineering. Subsequent degree were in related areas.
Sage's mission statement is to be a viable alternative to the MATLAB, Mathematica, Macsyma and Maple. A look at the toolboxes for MATLAB shows there are a number related to circuit simulation http://www.mathworks.com/products/product_listing/ Particulary SimElectronics http://www.mathworks.com/products/simelectronics/ RF Blockset http://www.mathworks.com/products/rfblockset/ So in some ways that might mean we should add such a tool to Sage.However, if there are better developed tools available for free, it would seem a little pointless to me to be reinventing the wheel. I personally would not consider using the tool shown - I don't think it is anywhere near as good as many free offerings. Without simulation of active devices, it will not compare favourably with ther tools. As I said earlier, Mathematica used to have a tool 'Nodal' but it appears no longer developed. (FWIW, if you look on the Mathematica newsgroup, many complain they can't make any reasonable about of money from selling Mathematica add-ons). The BIG plus for that tool was it could solve things symbolically. So if you drew two resistors in parallel, it could tell you the resistance was R1 R2 / (R 1 + R2), without you needing to put numeric values on R1 or R2. Such a tool is no doubt of less interest to most electronic engineers, who just want to simulate their circuit. For them, using one of the many more complete free tools is better. But for reserach purposes, symbolic results is a niche interest area and one where I feel Sage could be a 'must have' tool. But for general circuit simulation, I believe the tool shown is too limited. Would the oriiginal author of CircuitEngine be interested in substituing his numeric solving for symbolic solving? In that case, there is little need to stick to any standard like SPICE, as there are few if any tools able to do that. If someone had the MATLAB toolbox and knew how to use it, their views would be good. The following a quote from the most similar part of Simeletronics's functionality to that of the tool William showed: -------------------------- SimElectronics contains several libraries that enable you to incorporate electronic components into your model. Many types of transistors (such as JFET, NPN, PNP, and MOSFET) are included to let you include nonlinearities and high-frequency dynamics associated with these components. Models of integrated circuits, such as op-amps, enable you to design and verify circuits for analog amplification and control, such as a PID controller. The passive components library extends the basic Simscape library with models of devices such as variable capacitors and variable inductors which can be used for modeling custom components, such as sensors. A library of SPICE-compatible elements offers models of electronic components that use industry-standard SPICE parameters. It is also possible to include temperature dependence in your design using the SPICE-compatible elements. ---------------------------- Note the emphasis on SPICE. That's a must-have on any numeric based tool. For a symbolic tool, I'm not sure if SPICE would support it anyway. Dave --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to sage-devel-unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
