Brainstorm - improving TW for collaborative project design

Let's use this thread to discuss what you'd want to see me add to the site to better enable collaborative theremin project designing.  i.e. - if you wanted to work together with another reader to make a new theremin circuit or project, and you wanted to use TW as the "workspace" to do it on, what would you need me to add to the site?

The most important requirement, IMO, is the ability to exchange documents.

The ability to attach .pdf, .xls etc is, IMO, essential.

I would be happy to open a resource page on Element 14 where people could deposit any manner of file, and place a link to this here on TW.

I have created such a page here: http://www.element14.com/community/message/60835#60835/l/theremin-world-theremin

Will remove it if you do not aprove. ;-)

Fred.

http://www.simetrix.co.uk/

That's a link to a free spice based simulator that I've found very handy. It's results have so far been very close to real world circuits, and helped me spot problem areas before ever warming up my soldering iron.

If we all use this, or something compatible, we can share ideas in the form of functional, virtual circuits.

Hi W0ttm..

Simulation is a thorny issue - everyone has their favotites! IMO, there is only one simulator available free which is worth using - this is LT-Spice

Demo versions are fine and well - but having now used many (full) simulation packages (Starting with the original Berkley Spice in its raw form, then Spice-Age,Orcad,AnaSoft,Tina,EWB,Target, CadStar, Proteus and LT-Spice to name a few) I could write a review! LOL..

LT-Spice has no restrictions on use, is supported by a huge company, has a massive open-source data base and a huge user group, has unbelievable support, loads of on-line tutorials, is not a demo - is free and fully functional, regularly upgraded, and truly pro.

It also has an essential feature.. Most simulators, one attaches probes, then runs the simulation - If you want to probe some where else after the simulation has run (which can take an hour to get an audio waveform from a full theremin) you cannot - and need to replace the probes and run the simulation again.

With LT, you can probe a simulated circuit as if it was a board.

I now use two simulators - Proteus and LT.  Actually, LT is faster and more reliable than my £5000 Proteus for most analogue circuits (Proteus is far better on digital circuits, and can simulate MCU's etc as well, complete with code debugging - and it also has a PCB editor) I use Proteus because I can transfer schematics over to its excellent PCB design package - But if I was just doing simulation, I probably wouldnt use anything other than LT... Certainly dont need anything other than LT for analogue simulation.

LT is easy to use, it is optimised for fast analogue circuits.

BUT.

Simulators of every ilk are quite hopeless at ACCURATELY simulating LC oscillators - main reason is that the standard Spice inductor model is crap.. it doesnt model BH changes resulting from DC bias etc, it doesnt model real effects present in transformers.. The part of the theremin where one could really use a simulation to optimise the design, well, only hugely expensive simulators specific to design using magnetic components would be any use.. And in the time it took to learn to use this and develop the models, you could have built several theremins - and bought several RCA's for the money the program costs!

Fred.

"Simulators of every ilk are quite hopeless at ACCURATELY simulating LC oscillators" fred.

Well, there is that :)

Just thinking out loud (ok, with my keyboard).

I'll try LT.

Thanks...Rob.