Don't knock the old meters - that's all I had when I designed this sort of stuff. And a scope, of course.
The circuit you posted omits this essential 3rd stage and so cannot (usually) work . Extra phase shift in the opamps may add to the total shift and so work in some circumstances, but is unpredictable.
I'll post a working circuit if you like . a/ in principle or b/ detail - I'll have to figure that out.
Either needs a sub-circuit to control the gain to obtain a pure sinewave - do you need this? If any waveform will do and the frequency range limited, a 555 is easier.
The voltage divider is there to lower the voltage range to 0.5V to 1V (depending on the voltage you are running the oscillator at).Since you say you have a powered speaker, then that 0.5V to 1.0V signal could be fed into the input to the speaker amplifier... usually the 3.5mm jack plug that would go into a PC or MP3 player.
Hi,The link to the YouTube comes back as video unavailable.Tom....
That isn't a Biquad, as it has 3 90 degree phase shifts. Anything above 180 ought to work, though since there is no amplitude control it will be nearer a square than a sinewave output.You can't make a 555 deliver sinewaves.
Wien bridge oscillator
that would seem to be a confirmation of oscillation happening, right
anyway, i thought since i can't find a way to hear it, maybe we can just *see* it.
Just to make it explicit the criterion for an oscillator is a loop with gain greater or equal to 1.0 at some frequency where the phase shift is 360 degrees (or 720, or 1080, etc)
Just to make it explicit the criterion for an oscillator is a loop with gain greater or equal to 1.0 at some frequency where the phase shift is 360 degrees (or 720, or 1080, etc)The criterion for a pure sine oscillator is that the gain is exactly 1.0 (but it has to be more than 1.0 at the start to build up oscillations from nothing).
And, as somebody already said ..... connecting a regular external 'load' to your oscillator could mean that your whole oscillator circuit will change. In other words, it will no longer be your original oscillator circuit. This means that whatever you had designed before could be messed up because the external circuit changes your overall circuit.
s = jwWhere j is SQRT(-1) and w is the frequency in radians/second. It's 2* pi* frequency
Learn about Laplace transforms - a nice way to solve differential equations.A
There is a diode/no-lamp Wien config too.(BTW - The lamp doesn't glow.)
Yes it would appear so.Now while it is connected to the analogue input connect the speaker to see if it stops.
You need an amplifier so that you don't load the circuit. A computer speaker, one that needs a power supply, will be fine.
or alternatively, an amplifier circuit (here comes another op-amp !) to boost the signal, right ?