Hi Gary, I want to use the simulator for a Monte carlo analyse for the following question. To simplify what I mean is, imagine a bridge circuit with four resistors of 1% tolerance. The circuit is usable, if the bridge - voltage is below a certain limit. How many percent of my circuits are usable so that I can decide what's cheaper, to throw away the bad samples or use of more expensive resistors.
Do you know how this is done ? When I looked at the examples, they only calculated the worst case of a circuit, but that's not the question, I want to get the distribution of a parameter. Georg Afshin Salehi wrote: > > Just out of curiosity, what types of things do you guys run simulations on? Amplifiers, linear and switching power supplies, filters, and just about anything else that will need tweaking on the bench. > What drives you to run a simulation on that specific device? Testing for stability, what range of component values (tolerance) will work reliably, gain, rolloff, keeping signal levels away from the rails when designing high gain multi-stage amplifiers, and most important of all, gaining rapid insight into what happens when you go outside the box. Also, nothing catches fire or explodes in a simulator! >How accurate is the simulation to a real world bread boarded device? > Once you learn how to use simulation I would say about 98% accurate, but there is a giant proviso here, you must have accurate models and you must understand the limitations of the simulation process. I cannot remember the last time a finished product did not behave as the simulation did. The more often you simulate, the better you and your results get. > Jon Elson said it takes a day at first then maybe an hour or so each time to > remember things, how is that justified to your boss? I am really just > curious as to what things people run sims on, how complex those circuits > that are simulated are, and if the tests are worth while? > I use an old but very capable DOS version ($15,000 when new) of PSPICE. I can hand type an ASCII circuit description page in about a half-hour (three or four op-amps and twenty or thirty passive parts). Another twenty minutes to patch typos and missed connections. After the circuit is running you can do a number of tests in minutes that would take a week on the bench. Whether it is worth the trouble or not all depends on what you're doing. The last thing I did was a strain gauge amplifier (something I never did before). Had the circuit up and running in one afternoon, cost of components about $10 versus a packaged product with similar specs from Omega for $400. Is that worthwhile? My boss thought so. It all depends... Gary Packman > Thanks, > > Afshin > > ************************************************************************ > * Tracking #: 089C581B73790B40A34A5F9530FFA0A756B58F96 > * > ************************************************************************ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * To post a message: mailto:[EMAIL PROTECTED] * * To leave this list visit: * http://www.techservinc.com/protelusers/leave.html * * Contact the list manager: * mailto:[EMAIL PROTECTED] * * Forum Guidelines Rules: * http://www.techservinc.com/protelusers/forumrules.html * * Browse or Search previous postings: * http://www.mail-archive.com/[email protected] * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
