In my college we were asked to make a variable frequency function generator that make ( sine , square , sawtooth ) waves ,
i know that if i had a sine wave i can convert it using a zero detecting circuit with an op-amp to a square wave then using an op-amp as an integrator i can change it into a sawtooth wave BUT my main problem is to build a simple sine wave oscillator with variable frequency ,
i tried many oscillators ; wein bridge , colpitt , crystal and yet i cant find anything that works , if anyone can help please ??
i know that if i had a sine wave i can convert it using a zero detecting circuit with an op-amp to a square wave then using an op-amp as an integrator i can change it into a sawtooth wave BUT my main problem is to build a simple sine wave oscillator with variable frequency ,
i tried many oscillators ; wein bridge , colpitt , crystal and yet i cant find anything that works , if anyone can help please ??