An actual circuit

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Why the crossover at 15 seconds? I think reliable startup of the simulated symmetrical version has to be a simulation artefact.

Now I'm curious what the real circuit would do. I may have suitable parts.

We have a folder on a company shared drive called J:\Protos. Every project gets a sub-folder, like Z356 for example. The folder are logged in Protos.txt. There's another file that explains the rules.

A folder archives everything about a prototype. Schematic, data sheets, pictures of the built thing, test notes, scope pics, anything worth remembering. The proto board itself would be labeled Z356.

Some of the Z's are just parts tests or anything else worth documenting. Some are real multilayer PCBs.

This one is world-famous. It's in AoE3.

It's cheap and easy now to make a few double-side or multilayer PCBs for anything complex.

Nah. I build them inside the lid of a cast aluminum stomp box, and put a paper schematic inside. No worries.

More trouble than it’s worth IME.

Cheers

Phil Hobbs

True but you can reuse a speedwire board :)

What PCB design system/software do you use?

Mystrerious!

Maybe some math/Spice guru can suggest why.

I have seen oscillators that never started in Spice, absent being goosed somehow.

My LC Colpitts oscillators generally don't start on their own. In real life, I force them to start instantly.

It will no doubt start, from noise, part asymmetey, and the powerup transient.

Yuk! I remember how awful WireWrap protos were. I wrote a PDP-11 program to optimize wrapping, the traveling-salesman problem.

One nice thing about PCB protos is that you can keep them around forever, for future reference. Vias and ground planes and 50-ohm traces and edge-launch SMA connectors are all good. A spare unstuffed board or two is nice to have around too.

I often put several different circuits on one board, and shear them apart.

PADS. We've been using PADS since the DOS/floppy disk days. It works well enough. We use the same ever-growing parts library and can open decades-old projects.

What's weird is that Digikey has cheap proto "redboards" now but claim that they won't work from PADS files. Gerbers is Gerbers, I'd think.

Where do you document the results?

Depends. If it’s a small test instrument, usually in my lab book. If it’s for a product or an experiment, I mostly use Markdown files in the corresponding git repository.

We keep private repos on github and gitlab, as well as bare repos on various computers and NAS boxes in different locations.

Cheers

Phil Hobbs

I have 7 engineers now, and we've structured the prototyping and subsequent learning to encourage knowledge and experience sharing.

Our material control system tries to do that too. Every part in stock has an optional PDATA folder with data sheets, test data, notes, warnings.

Search results <opamp++buggy> 05-25-2024

PART CLASS SUBCLASS DESCRIPTION MFR1 MPN1 PRICE STOCK OLD PART ======== ============ ================ ======================== ========== ================= ======= ====== ========

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I hated wire wrap but liked speedwire. If it wasn't speedwire it was a soldering iron and what we called veroboard. Non shrink-back ptfe wire was useful too.

Ok not one I've used.

Yes I've had that problem. I think it was OrCAD which couldn't open older versions of its own files.