no phase difference

[zhujun]

Hello
How to design a analog circuit which has the function following:
the input signal of the circuit is a 50-to-450 Hz sine wave,

1Vrms,the output signal has the same waveform, same frequency,

especially no phase difference(no lead & no lag) with input wave,

other electric characteristics need not care. How to design? Can you

help me?

[Kevin Weddle]

What do you want to do with the input signal. Amplify, filter, modulate with another signal, or change the complete nature of by adding a complex filter. Zero phase difference means selecting the right components. You can realize this even with a complex circuit as long as you can keep track of the phase. I think maybe you are getting at the 180 degrees presented by an inversion. This can confusing, as can be the reasons behind the 90 degree phase differences. The 180 degrees has zero time difference while the 90 degrees has a discrete time difference. This means everything when you plot the occurance with repsect to time on graph paper. You can invert and then reinvert without net effect, but once you set the reactive component, you can get time difference after time difference until you get zero time difference. When this occurs, you have the exact same signal occuring at two places at the same time.

[zhujun]

KEVIN,thanks

The input signal,goes into a power amplifying part,is from a digital signal source.The loads of power amplifying part are inductive or capacitive. A phase shifting would occur between input signal and output signal from power amplifying part. Let output signal to keep track of the input signal phase,nothing done with the input signal.

[surajbarkale]

So do you basically need a phase corrector which would correct the phase of voltage despite of the changes in load? ???

[Kevin Weddle]

Did you mean some sort of feedback. Do you want the phase to be equal so that you can directly change the input signal. Often a large feedback loop can be acceptable. If you want to use a large feedback loop you have to use a servo circuit. Direct feedback will produce a net result. And yes you might want to get the phase the same. Just use a two channel oscilloscope and adjust the phase using a reactive load on the power amplifier. All you need is an inductor or capacitor and a resistor. This will correct the time.