Search Results

Here is a short description of the PRINCIPLE: Think of an oscillator as an AMPLIFIER that is able to produce its own input signal - for one frequency only. … Then, connect the amplifier output to the bandpass input (both form a closed loop) - and you have a working oscillator. …

The circuit can be transferred to an oscillator by closing the loop using another resistor R between opamp output and filter input (resp the finite filter input resistance, which is identical to R1 at …

Andy aka has explained why the 741 type opamp is not a proper choice. You need an other opamp which has a unity gain bandwidth which is at least 10 times larger than your oscillation frequency. More t …

Cdummie, the shown diagram contains one of the classical methods for soft-limiting the output amplitude of a sinusoidal oscillator. …

The principle of a working oscillator is a closed feedback loop. However, this criterion is applied to the system when the loop is opened at a suitable node. …

Comment to the phase shift oscillator (see Tony Stewarts answer): This double-integrator loop is a very interesting one. … In most (if not in all) contributions where this oscillator is explained, nothing is said about amplitude control. …

Such an oscillator can be seen as an amplifier that creates its own input signal. …

" The systematic approach for designing this oscillator is as follows: Start with the oscillation condition: Unity loop gain at the desired frequency wo. …

This allows a 360 deg phase shift at the oscillator frequency fo. …

Why do you think, that the "feedback" would be C1/C2 ?? The feedback path is a 3rd-order lowpass (ladder structure) which assumes at one single frequency (the desired oscillation frequency) a phase sh …

"R1 and R4 are low value resistors, am I right in thinking they just limit the current going into the transistors? Do they have any other purpose?" It is a common misunderstanding that these collecto …

Hence, the circuit cannot work as a n oscillator. (The imag. part of the transfer function always must contain a difference in order to become zero for a finite frequency). …

Each working oscillator needs (a) negative feeedback for DC (stable DC operating point), and (b) positive feedback for a single frequency, in particular: Loop gain with zero deg. phase shift and a gain …

For such a diode-stabilized WIEN oscillator you always have various options. One option you have shown with two equal resistors R22 in the parallel path. … Result (oscillator amplitude): Vout,max=(3/2)*465.5=698.3mV( Simulation result: Vout,max=730 mV) UPDATE/EDIT: Due to a simple calculation error I have corrected the above given values. …

Some supplementary remarks (to jp314`s answer): Growing oscillation amplitudes will be limited (clipped) by the opamp stage with largest gain - and, in this case, it is the first opamp (DC gain is R …