Circuit drawn from TheCircuitPro app.
I modified the upper resistor value from 1k to 5.6k for generating square waves
To start the simulation just shake the phone or push once the push-button.
To modify the frequency, increase or decrease the value of the inductor or capacitor ( in the original circuit the value is 100mH, frequency is about 180 Hz)
In the original schematic the resistor parallel with the condenser was 5k and the voltage of the sine wave slowly increased to +/- 24V when the app enters in "Cannot find solution" mode. My problem was to limit the sine wave voltage to a reasonable value (10V). I made it with 2 zenner diodes but these will affect the shape of sine. Another method is to modify the value of the resistor parallel with the condenser from 5k to 2k without affecting the shape.
Somehow the timestep of simulation will affect the function of the app (Cannot find solution)
Just play with values and have patience. Have fun :)
Later edit: somehow the sine wave is stabilized to +/- 20V and do not enter in "Cannot find solution" mode :))
It's working! I haven't try it in real :)
