Can't get sine wave out of this circuit in Proteus. Can you help me, please? I'm suppose to have sine wave generator with range 1 kHz – 200 kHz. While googling came across the current circuit, but can't get it work. It's showing DC output e.g. straight line without any shape or change. Can you help me?
Best Answer
Oscillators often need some kind of "kick" to get started. In the real world, this comes from noise, or from the transient when power is first applied. But by default a SPICE style transient simulation will be noise free, and start from an operating point determined by a DC analysis.
One solution is to replace B1 with a transient step source that goes from 0 to 9 V at some time just after t=0 (like t = 1 us, maybe). (A fussier way would be to specify initial conditions for one of the capacitors that aren't equal to the dc operating point condition)
Also, some oscillators take a while to get started. If your oscillator isn't a strong one (I can see how your oscillator works but I don't work on oscillators every day, so I don't know what are the gotchas for this particular circuit) you may need to simulate for a pretty long time (1000's of cycles or more) to see the oscillation start and settle down to a steady state condition.