555 volume control

Posted: 6/6/2012 6:09:36 AM

Joined: 3/18/2012

 Thanks Fred for your efforts and the link to LTspice.

Posted: 6/6/2012 2:22:48 PM

From: Northern NJ, USA

Joined: 2/17/2012

"LTspice is a good free simulator..."

AIM-Spice is good and free as well:


Posted: 6/6/2012 8:42:57 PM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

"AIM-Spice is good and free as well" - Dewster

Hi Dewster,

I know this is a bit OT.. Had a look on the AIM-Spice site, and there was not a lot of information - I am always interested in new simulators, if you use this one, perhaps you can answer my questions:

1.) There is no mention of or pictures of schematic capture - Does this simulator include this? Can one probe the schematic when (after) the simulation has run?

2.) This seems to be available as evaluation download (free) or purchased ($190 or $75 for academic) - but no details are given about what the limitations are on the evaluation version.

One of the things I like about LT-Spice is the huge user-supported database of models etc - I dont like its schematic capture, but it is usable and ok if one was to make it your main tool - its just that it has some obscure operations which I tend to forget because I dont use it often. In terms of speed and probing options, this simulator knocks the cr*p out of any other simulator I have ever used - My main Capture/Simulation/PCB package (Proteus) cost me about £1000 - And I have used Orcad (package costing £9k), and neither of these is as quick ore easy as LT-Spice when it comes to actually running the simulation and deriving useful data from it.

The main (IMO) +Ve feature of LT-Spice is the probing.. My other simulators require one to attach probes to the schematic before one runs the simulation.. With LT-Spice one can run the simulation and probe the circuit after simulation is completed..

Simulating complex circuits can take a long time (I have often left a simulation to run all night, particularly when combining HF signal manipulations / heterodyning etc, and wanting to examine the audio frequency outputs) (I often run simulations at highest possible resolution, so that I can actually listen to the audio produced by the circuits) - Once the simulation is completed, the display (for simulators other than LT) shows the traces for points one has connected probes to - one is limited in the number of probes one can connect, and if one finds something one did not expect, one needs to attach new probes for further examination, and re-run the simulation -

With LT-Spice, one simply probes the schematic as if it was a running circuit on your bench - no need to carefully plan your probe placement, freedom to examine unexpected results.

And LT-Spice is completely free - no evaluation versions or limitations.

And no - I dont work for or get commission from Linear Technology! ;-)


Posted: 6/7/2012 4:11:52 AM

From: Northern NJ, USA

Joined: 2/17/2012

Fred, you've used LTSpice much more than I have, and your review of it is quite informative (I tend to hang out in verilog simulators).  I stumbled across AIM-Spice when I was looking for free Spice simulators (had access to Orcad at work but didn't want to go through the rigamarole of licensing) and it proved to be stable and intuitive, but I tend to prefer text entry over schematic entry, and probing after the fact was wasn't a consideration (though I can certainly see how it could be very useful).  I don't think they are very strict about the evaluation (no nag screens) but I haven't tried the very latest version yet.

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