LTSpice initial conditions help, please?

[eTech]

From my point of view, wasting time trying to simulate something I could just prototype was the cheat; it was just curiosity as to how well it could simulate - which it didn't, due to faulty component models. That makes the tool worthless.

That doesn't make the tool worthless. It makes the model worthless.

 

[Papabravo]

IMHO the main value of simulation is understanding. In addition, it is a poor workman that faults his tools.

 

[Papabravo]

From my point of view, wasting time trying to simulate something I could just prototype was the cheat; it was just curiosity as to how well it could simulate - which it didn't, due to faulty component models. That makes the tool worthless.

The actual power input circuit works fine from under 40V to over 120V without undue heat or current.

I've never got on with simulators, and most of the stuff I build cannot be simulated in any practical sense anyway.

What would you be willing to pay for certified and verified models? I'll wager large sums it would not be enough to compensate those who do the work. That's probably the main reason there is no such thing.

 

[Lightium]

I gave up on simulations and just built a test circuit to work out the optimum values.

What construction technique do you use to make boards?

 

[rjenkinsgb]

In addition, it is a poor workman that faults his tools.

That is outdated, from the time when workmen made their own tools! A carpenter blaming a chisel he made himself etc.
I did not make the component models. I would never blame a tool I made or designed, that's idiotic.

What would you be willing to pay for certified and verified models?

Nothing. I've been running an industrial electronics design, programming, manufacturing and repair business for ~50 years from when I left school and never needed a simulator. I often have work queued up for months ahead.

If I were designing integrated circuits or the like where prototyping and one-offs are not practical until a design has been tested exhaustively, it would be a very different matter.

I somehow doubt anyone is producing integrated circuits with a free simulator and models, though. You get what you pay for - they would have support and any component model bugs likely fixed in hours.


I like building things and working with my hands, whether electronics or any other craft. Most of my hobbies include physical, detail work.

What type of "stuff" is that?

Hardware that must interact with other devices & equipment to function.
Microprocessor based devices that need to run at full speed for any valid results.
Software that needs the above hardware (or industrial control hardware) to function.

Audio / microphone preamps etc., where the quality of the end result is down to the quality (noise levels) of the components used, rather than the circuit itself, which is fairly trivial. Plus the overall design and appeal of the PCB layout and ease of construction for the hobbyists I'm selling to.

General gadgets and test gear; 3D printed parts.

And a lot! of software, both hobby and work.


The last major "bug" I had on a (hobby) project recently was down to bad parts - common small TFT displays.
They either have connections omitted or clone driver ICs that do not operate as the real (and claimed) IC does when reading back data.

The first type gave no output whatsoever; the second type gave garbled output, regardless of SPI speed. Both types worked immaculately for display, with SPI speeds up to 50MHz; but would not read back data accurately even at a fraction of the rated read speed.

I ended up with a parallel interface type instead, which works fine - but all are different sizes and I had to re-work the enclosure bezel design for each different display. The original types had mounting holes where the final one has no provision for panel mounting, it needed an extra clamp frame to attach to a panel.
That clamp frame had to be wider and deeper than needed for displays with fixing holes and in turn needed the case body design adjusting.

 

[rjenkinsgb]

What construction technique do you use to make boards?

For testing the inrush limiter, just components strung together to the DC-DC module with load resistors attached.

For most prototypes / one-offs / test gear, stripboard, either normal stuff or ground plane, depending what it is. Then either point to point soldered connections or wire wrap.

This is the last bit of test gear I built, a few weeks ago - I needed something to monitor the position encoders on a large machine tool, as one axis was not returning to the same position when referenced.
I knocked up a two channel counter that could monitor the encoder signal to the CNC:

Bench testing with an encoder: