LT Spice looks

Picture is worth a thousand words here.

Different ?

RL

Mostly fonts. Some can come from different settings, but even with the same settings things are weird.

As one zooms in and out, font scaling does not track graphic scaling. Try it. The length of strings jumps around. So if you make something look good at some zoom level, it gets ugly at others, like text overlapping parts and such.

And there are different grids for parts and lines and for different kinds of text. So it's hard to keep stuff aligned.

All that makes it hard to draw a neat schematic.

I believe that a beautiful schematic, for simulation or for a real PCB, works better than an ugly schematic.

I see real horrors posted here, and elsewhere.

It's always done that since I've been using it.

I've worked in plenty of places where you didn't get to draw your own schematic so you just had to deal with the fact that although it produced a correct netlist it didn't look anything like what you'd have drawn yourself.

If the netlist and PCB layout is correct then why waste time on making the schematic look like you want it, only to be told by someone else that they would have drawn it completely differently?

The time spent making a schematic look good is essentially another design review, more eyeball time on the problem.

And who dares to order a design engineer to change his schematic?

Well, I do insist that my engineers treat a Spice schematic like a real document, with proper title block, author, date revision control.

The sloppy software hacking mentality is terrible when applied to hardware design.

A good engineer will do that anyway, but it doesn't necessarily mean that the design will look good to someone else.

LOL some of the managers I've worked for. And drawing office people who weren't going to let you use your own logic symbols or other symbols.

But not long ago you were agreeing with me about trying things out, either in your mind or as an experimental prototype. Isn't that just like trying things out in software? One place I worked tried to get to just two PCB iterations before production. My comment at the time was that software should also be told that they can only compile it twice.

I remember long ago when we had draftsmen who took sketches and drew schematics on paper, with straight lines. Some of their stuff was ugly too.

Now, most engineers enter schematics themselves. All the logic symbols come out of a company-shared library.

I still like to start with a D-size pencil-on-paper schematic, partly because I don't need to use library parts at the early stage of design.

Simulations, sketches, brainstorming, breadboards are quick and easy, and encourage people to think and change their minds. But production-quality multilayer PC boards are not the most efficient way to experiment.

Our goal is one: sell rev A.

When we worked on paper, with punched tape or cards, we'd actually READ our code before we assembled and ran. I wrote one RTOS while visiting a friend in Juneau Alaska and mailed hand-written pages back to the home office to be punched and assembed and tested. It had one bug.

Yes. I had this problem the other day with that oscillator Edward posted.

I sometimes draw parts of a circuit on paper, usually when I want to calculate something or sketch/brainstorm something, but I haven't drawn a full schematic on paper directly myself since somewhere around 1988.

Ok so the question is when do you switch from Simulations, sketches, brainstorming etc to revision control? The schematics people post here are not usually under revision control so they don't need "proper title block, author, date revision control." I can think of no reason why anyone would get upset about the absence of this information on such a schematic.

When I first wrote some code which was going to be run for me, the form I filled in was taken elsewhere and manually transferred to punch cards which were then fed into the computer which I never saw. The output was returned to me on paper. A transcription error caused my first program to fail. It was clear to me at the time that if only I could have my own computer to see the output immediately then I could run, test, run, test, experiment, run test and eventually arrive at a program I was happy with.

When I actually got a computer which could run my own code I had to put the kit together myself and enter the code bytes myself.

It answers the questions What the hell is this? Who did this?

A few years later, it's best to know this stuff.

The easier it is to run something, the less checking will be done, and the more bugs there will be. Bridges and buildings and airplanes get checked before they are built so have less bugs than Windows.

Once it's in my filing system it will probably never be seen again.

You might want to talk to Boeing about that. Not to mention

Never see the Spice model again? That certainly reduces the documentation requirements.

Around here, even whiteboard sketches are titled and dated and photographed and archived in a project folder.

The door plug blowout was a field assembly error. Required parts weren't installed.

Building collapses usually happen because the construction is not in conformance with the signed-off drawings.

Our drawings define the end product, but usually don't detail every steps that manufacturing uses to achieve conformance to drawings. QC does inspect the final assemblies for conformance to all released documents.

If I worked in whiteboard marketing I'd certainly push that as a must have. Must be more than 30 years ago when I first saw a whiteboard which could put it all on paper. I'm not sure what happened to the papers. They were likely filed and...

I'm sure they would have had such a whiteboard here:

We just write the title, peoples names, and the date and shoot a pic with a cell phone.

If you were a service engineer with the customer breathing down your neck, which diagram would you prefer, 'A' or 'B' ?

They are both wrong.

Do you mean they wouldn't work or do you mean they aren't drawn to some arbitrary standard?

When I was a service engineer there was no such thing as a schematic and I often had to make do without a circuit diagram at all. On rare occasions a repair had to wait for a circuit diagram to arrive by post and when it did it could easily contain circuit A.

I'm not suggesting that your B layout isn't preferable but in the real world A will often be encountered.

Won't work. The batteries are backwards.

It depends which battery convention you use, there doesn't seem to be a standard which is universally accepted.

As a footnote, some transistors have enough gain int the reverse direction to make the circuit function, after a fashion, from either polarity. When I worked as a tester on a production line, we were puzzled by the audio stages of some of the receivers working below spec. Everything seemed all right except the high frequency response was below the test limits. Eventually I tracked it down to one of the transistors being put in backwards by the girls making the boards.