Variable frequency sine wave

Thread Starter

gagan

Joined Sep 20, 2009
2
hey guys. I want to build a variable frequency sine wave generator with a constant amplitude. any suggestions??

Thanks,
G
 

Audioguru

Joined Dec 20, 2007
11,248
A Wien Bridge oscillator using a light bulb or a Jfet for amplitude stabilization works well.
Mine goes from 10Hz to 100kHz.
 

Thread Starter

gagan

Joined Sep 20, 2009
2
hey thanks for the quick reply

I'm considering the following circuit
http://www.national.com/ms/LB/LB-16.pdf
Figure 1 Easily tuned sine wave oscillator

Can any one help me by explaining what exactly how sine wave is being genrated in the circuit.

Audioguru:- I did consider wien bridge option but can't figure out how to control the amplitude using jfet exactly. If you could explain a bit more on that part, then it will be great.

Thanks
 

Wendy

Joined Mar 24, 2008
23,415
How pure does this sine wave have to be? If the answer is not extremely, then you can use other methods.



To answer your question the Zeners clip the wave form, leaving what is effectively an active filter to clean up the harmonics.
 
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