A synchronous detector can determine a signed output voltage that relates to the displacement.
2.
You then use a synchronous detector that samples the peaks of the AC signal, which are equivalent to the original DC value.
3.
For example, for a signal modulated with a linear modulation like AM ( amplitude modulation ), we can use a synchronous detector.
4.
To recover the'stereo'audio signals, a'synchronous detector'is utilized to extract the L-R audio from the phase modulated quadrature portion of the signal created in stage 2.