Here is Wien oscillator with amplitude stabilization:



Amplitude of oscillations, Vout, is about 10V. If I put step up transformer on output with appropriate primary/secondary ratio, I can get 220V AC voltage, and it would be some basic DC to AC inverter, right? But because of small output current of LM741, it can't be used to power bulb for example?

 

Voltage level is always easy. The current is the bitch.

 

You would need a circuit to boost the current before transformation. Also, you need a DC power supply of sufficient power for the light bulb.

 

Given the low resistor values connected to its output, Idoubt that the 741 could make 10 mA at 10 Vpeak, even at a freq as low as 60 Hz. But if it could, and that 7 Vrms went through a 30:1 transformer to make 210 Vrms, the 7 mA would be reduced to 230 microamps. In this situation the opamp is making 50 milliwatts, and the transformer output will be less than that. That is less than 1% of what it takes to light a nightlight.

ak