Sine wave generator

[Noonie]

Hi,
I am doing a project on a sine wave generator circuit. problem: when I
simulated it, it gave me triangular wave instead of sine!!!
So, Could you please help me discover what's wrong?!
The circuit schematic is on the following site:
xoomer.virgilio.it/fladelle/Page13.htm

Thanks in advance...

 

[Fred Bloggs]

Hi,
I am doing a project on a sine wave generator circuit. problem: when I
simulated it, it gave me triangular wave instead of sine!!!
So, Could you please help me discover what's wrong?!
The circuit schematic is on the following site:
xoomer.virgilio.it/fladelle/Page13.htm

Thanks in advance...

The most likely problem is that the thermal time constant of your
incandescent bulb is too short- this is a non-trivial modeling problem
that requires you to produce a resistance as a non-linear function of an
integration of the RMS bulb current over several thermal time constants
of past history. I have never done this simulation but it seems the only
hope of producing a useful SPICE simulation would be to bound the
circuit by theoretical calculation, linearize a bulb model around small
variation at steady state, and run a circuit model with calculated
steady state node initialization values. Have fun...

 

[John Woodgate]

I read in sci.electronics.design that Fred Bloggs <[email protected]>

I have never done this simulation but it seems the only
hope of producing a useful SPICE simulation would be to bound the
circuit by theoretical calculation, linearize a bulb model around small
variation at steady state, and run a circuit model with calculated
steady state node initialization values.

I doubt if it's as simple as that. (;-)

Just build it and see if the simulation is correct. By the time you've
corrected the simulation from first principles, you could probably have
built and tested a hundred oscillators.