I am trying to build a sine wave generator with a frequency adjustment and amplitude adjustment then once set I want to progressively change the phase. I can find a circuit for the first part but how can I change the phase of a sine wave generator progressively through 360 degrees?

 

You will have to add more explanation to your need to change the phase. Phase relative to what? The oscillator must operate with a fixed phase relationship, or it will stop oscillating.

 

Progressively advance or retard the phase to get match with base frequency on the scope

 

Progressively advance or retard the phase to get match with base frequency on the scope

Is that all, or is it part of some application.?

 

It is a technology named phase-locked loop or phase lock loop (PLL). I have never used it. But you may Google the term.

 

The application is to find the phase of a natural oscillation where the frequency and amplitude can be determined but the phase cannot. By progressively changing the frequency the point of cancellation will indicate 180 out of phase.

 

It is a design element named allpass filter. It may do some of what you want. Use Google for more info

 

Yes that looks like a good lead. Thanks

 

A few decades ago, I did this for a color background generator for broadcast television. One thing that made it easy was that the design only had to work on the NTSC color frequency 3.59MHz. The circuit was basically an analog computer that solved the trigonometric equation sin(ωt +θ) = Cos(ωt)Sin(θ) + Sin(ωt)Cos(θ). I generated Sin(θ) and Cos(θ) from a sin-cosine potentiometer and I designed a circuit that created the 3.59MHz and the same frequency shifted by 90 degrees. I then fed these signals into a couple of four-quadrant analog multiplier ICs and then summed the outputs from the two mulitpliers to produce the final result. It worked very well.

hgmjr

 

I am trying to build a sine wave generator with a frequency adjustment and amplitude adjustment then once set I want to progressively change the phase. I can find a circuit for the first part but how can I change the phase of a sine wave generator progressively through 360 degrees?

As beenthere said, phase relative to what? Do you mean to create an oscillator with two outputs, where one is shifted by some phase from the other?

Progressively advance or retard the phase to get match with base frequency on the scope

Isn´t that what trigger and trigger delay is for?

 

Isn´t that what trigger and trigger delay is for?

The post suggests that the OP would hardly know what are these.

 

Using the scope would only be to test that the circuit can change frequency, amplitude and then progressively change the phasing. In the application in the medical field it would only be the patient that could know when the phase was 180 out of phase by the cancellation response. The phase cannot be detected directly.

 

Can you elaborate more on what you are trying to do. What kind of medical application is this.

 

....when the phase was 180 out of phase...

Let me ask once again, out of phase with what? To be able to talk about phase, you need to have TWO signals. So what is the second one?

Unless you are able to explain us what youre actually trying to do, there is little point discussing it any further.