Hello everyone!
I spent months doing this spreadsheet, trying to make something that has its worth in the help of designing a BJT CE amplifier stage. Really simple, resistive base divider, resistor on the emitter to linearize, collector resistor for simplicity... But the transistor model is quite accurate, it's the same effect as Falstad circuit simulator, and the hard part was to make it work with Early effect. It shows the load line, the point you chose for the transistor saturation, the point you chose for the cut-off, the quiescent point, and the maximum and minimum points that the amplifier gets to when the input has that much peak voltage.
I recommend to read the "How to use" sheet to know some quirks of the way I did the calculations.
To reinforce, it's not guaranteed the convergence as in a simulator because it's a spreadsheet. I know I could use Excel with Python to use a script and spreadsheet at the same time. Maybe someday I'll do it. For now it agrees with simulations, so I think there could only be minimal errors.
Link to the spreadsheet - sorry for using an unknown software, but I went for it because google sheets would get me bored, the visual of Zoho is better for me. It just doesn't have the feature of circular references (iterations).
I'm looking for suggestions in how to improve it, but doubts in how to use are welcomed too, because maybe it's not clear how to use it, and probably I'll have to update the how to use part.
Let me know what you guys think of it.

 

I applaud anyone who uses spreadsheets to solve problems. Recently I wrote a VBA macro to do FFT on a square wave and sine wave to check my algorithm was right before writing code for a processor. Maybe “Mathcad” is better but spreadsheets are so quick and easy

 

I applaud anyone who uses spreadsheets to solve problems. Recently I wrote a VBA macro to do FFT on a square wave and sine wave to check my algorithm was right before writing code for a processor. Maybe “Mathcad” is better but spreadsheets are so quick and easy

Thank you, I also think the same way, Mathcad is more useful, in my view (the little I used many years ago), if you deal more with equations than numbers. Spreadsheets are wonderful for quick changes of inputs to analyze the behavior. I also did FFT few years ago at my job when I needed, but it wasn't with VBA.

 

.....for quick changes of inputs to analyze the behavior.

In this context, perhaps also interesting:
Based on the known equations for transistor amplifiers (Shockley equation), I created a large-signal SPICE-based model consisting of a block diagram (summing junctions, multipliers, amplifiers, transfer functions) as is known from control engineering.
This allows both the classic transistor characteristics and the amplification properties to be demonstrated.
The various SPICE-analyses are possible: DC, AC, TRAN.
All parameters (B, Early voltage, DC operating point, load impedance, etc.) can be varied as desired.
Unlike the classic SPICE model, the block diagram illustrates how the bipolar transistor works as an amplifier or as a switch.
This model is, therefore, primarily intended for educational purposes

 

In this context, perhaps also interesting:
Based on the known equations for transistor amplifiers (Shockley equation), I created a large-signal SPICE-based model consisting of a block diagram (summing junctions, multipliers, amplifiers, transfer functions) as is known from control engineering.
This allows both the classic transistor characteristics and the amplification properties to be demonstrated.
The various SPICE-analyses are possible: DC, AC, TRAN.
All parameters (B, Early voltage, DC operating point, load impedance, etc.) can be varied as desired.
Unlike the classic SPICE model, the block diagram illustrates how the bipolar transistor works as an amplifier or as a switch.
This model is, therefore, primarily intended for educational purposes

Where I can access this SPICE-based model?

 

Where I can access this SPICE-based model?

You need no specific access - if you are interested, I can post a picture of the block diagram in this forum (due to time shortage only tomorrow).

 

You need no specific access - if you are interested, I can post a picture of the block diagram in this forum (due to time shortage only tomorrow).

I'm really interested, would be so nice to see similar efforts of what I did.

 

Here comes the block diagram (npn transistor, common emitter gain stage, see the enclosed jpg-files (diagram and description).
As an example, I have enclosed a jpg-file showing the Ic=f(Vce) characteristic for Vbe=const.

 

I am impressed! This is certainly a much more in-depth modeling effort than I have seen or used. Thanks for sharing it. with us.

 

I am impressed! This is certainly a much more in-depth modeling effort than I have seen or used. Thanks for sharing it. with us.

Thank you.
I like to mention that I am very interested in some comments to the shown block diagram (errors, improvements, restrictions,...)

 

That diagram in post #8 is quite complex, and it may not match the amplifiers that I have created, at least in all of the terminology.

Probably my amplifier choices are much more application based, with the majority being either instrumentation amps from strain gage inputs or audio amps with either microphone or transducer inputs and speaker or line level outputs.