krets
Electronic circuit analysis in Clojure using Modified Nodal Analysis. Extremely rudimentary.
During 1996-97 I was writing a Nord Lead clone in C++, which kind of worked but was never properly finished. So almost 20 years later, I've decided to start working on another software synthesizer using a different approach. I'm learning a lot - I haven't looked at electronics since high school - and I'm mainly having fun exploring the subject.
The goal here is real-time circuit modelling of an analog synthesizer. A mildly realistic target is the Music From Outer Space Noise Toaster which is the subject of Ray Wilson's book Make: Analog Synthesizers A first step towards that is the Alien Screamer. This repository is very far from that goal though! I expect to ditch Clojure for some other language - Rust, Nim or C - once (and if) I figure out how it's supposed to work.
To achieve this we need to be able to simulate V voltage sources , I current sources, E voltage controlled voltage sources, R resistors, C capacitors, D diodes, Q bipolar junction transistors, J junction gate field-effect transistors and X for simple sub circuits like op amps and potentiometers. Preferably in real-time. There's no intention (or enough knowledge) to build a full-fledged general purpose circuit simulator.
The industry standard circuit simulator is called Spice. 'Krets' is Swedish for circuit.
Tests and initial implementation guidance from http://www.ecircuitcenter.com/SPICEtopics.htm Non-linear models are based on the Qucs technical papers and source code.
References
Synthesizers
DIY Analogs
Software Circuit Simulation
- http://www.u-he.com/cms/diva
- http://www.rolandus.com/blog/2014/02/14/analog-circuit-behavior-acb/
- http://www.arturia.com/cs-80v/tae%C2%AE
- http://www.cytomic.com/drop
Industry conference for plugin developers.
Modified Nodal Analysis / Electronics
This is the technique used by Spice and most other simulators.
- http://www.swarthmore.edu/NatSci/echeeve1/Ref/mna/MNA_All.html
- http://www.ecircuitcenter.com/SPICEtopics.htm
- http://qucs.sourceforge.net/docs/technical/technical.pdf
- https://xyce.sandia.gov/downloads/_assets/documents/Xyce_Math_Formulation.pdf
- http://www.allaboutcircuits.com/
- https://ccrma.stanford.edu/~dtyeh/papers/DavidYehThesissinglesided.pdf
Spice
- http://bwrcs.eecs.berkeley.edu/Classes/IcBook/SPICE/
- http://www.linear.com/designtools/software/#LTspice
- http://newton.ex.ac.uk/teaching/CDHW/Electronics2/userguide/
- http://www.allaboutcircuits.com/vol_5/chpt_7/8.html
Other MNA simulators
- http://www.falstad.com/circuit/ (Java)
- https://github.com/zupolgec/circuit-simulator (JavaScript)
- https://github.com/Qucs/qucs/ (C++)
- http://www.gnucap.org/ (C++)
- https://github.com/ahkab/ahkab (Python)
- http://www.livespice.org/ (C#)
Wave Digital Filters
Another interesting approach, needs more hands-on knowledge to manage circuits with multiple non-linear elements (like diodes and transistors).
- https://ccrma.stanford.edu/~dtyeh/papers/wdftutorial.pdf
- http://www.nireaktor.com/reaktor-tutorials/wave-digital-filters-in-reaktor/
- http://home.deib.polimi.it/sarti/CV_and_publications_files/2010_IEEE_TrASLP_virtual_analog_modeling_WD.pdf
- http://legacy.spa.aalto.fi/software/BlockCompiler/
Yet another approach, based on random walks:
VST Development
Dependencies
Dev
Experimental
License
Copyright © 2015 Håkan Råberg
Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.