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you can insert a capacitor to the output like this, I suppose?:
https://www.electro-tech-online.com/attachments/555-inverter-png.35806/
Hello
Can you guys please tell me how to convert the output of this square wave oscillator (the output is ramp after passing through R1 & C1) so that its output become SINE wave?
I have to do so with minimum changes in the circuit.
If you have a F Hz square wave with no offset then you won't have DC. You are going to have the odd harmonics. So if you are running at F Hz, you are going to have sine waves F Hz, 3*F Hz, 5*F Hz... (2n-1)*F Hz.
You have to build a low pass filter that attenuates frequencies higher than F Hz.
Well Thanks for all inputs,
I do not want to practically do so, Just want to know if it is possible to extract any sine wave in the output of the above circuit without adding any other components?
y professor wanted me to design a sine wave generator using op-amps, I just designed the above, but finally I noticed that the out put is square before the output filter, and ramp after the output low pass filter.
Any idea how to use this circuit to be able to get an sine output without or wit minimum component changes?
Can we adjust the low pass filter so that its output become sine? Or working with the components values? It's no matter if we could not get an stable or good sine, just something to show that the circuit is able to work as a sine generator will be enough (As I told even a very poor one is more than enough).
Also, as mentioned prev. an additional RC after the triangle will give an ok sinewave, see attached.
View attachment 37964
As you can see, the amplitude is down a fair bit. (plots are scaled: ramp*15, sine*250)
I guess. You can remove those diodes and 10k resistor from the oscillator feedback path as they appear useless. Now connect a huge resistor from the output of the triangle wave to the 2 diode back-to-back (acting as a tiny capacitor). This likely won't work in practice, but with a few assumptions it will work on paper.Good idea, thanks for it, but can I do it by adding no component?
It reduces the harmonics of the squarewave. Read up on harmonics of a squarewave. Have a look at the animation on Square wave - Wikipedia, the free encyclopedia - it shows what happens as you add more harmonics (sinewaves that have higher frequency than the fundamental - for a squarewave the harmonics are an odd integer multiple of the fundamental frequency) together; the more harmonics, the more like a squarewave the result becomes. Conversely, if you have a squarewave and remove the harmonics with a low pass filter, you will get more rounded waves and eventually a sinewave.Besides Can you let me know how it does work?
Thanks
You designed a simple square-wave and triangle-wave generator then added the most simple filter that is possible (a single resistor and capacitor). Of course its sine-wave is bad.My professor wanted me to design a sine wave generator using op-amps, I just designed the above, But finally I noticed that the out put is square before the output filter, and ramp after the output low pass filter.
Any idea how to use this circuit to be able to get an sine output without or with minimum component changes?