I am working on the project related to zero cross detection. But I can't find the right logic for zero cross detection of an ac signal if any one can help me out into this then please tell me?
I am working on the project related to zero cross detection. But I can't find the right logic for zero cross detection of an ac signal if any one can help me out into this then please tell me?
A Comparator is usually the first thing you would try. Freescale has an app note below. Keep in mind that things will tend to get noisy as the signal drops to zero so good timing requires careful layout and and good filtering.
http://cache.freescale.com/files/microcontrollers/doc/app_note/AN3552.pdf
2.6 Function 6: Zero Crossing Detector
Figure 14. Zero Crossing Detector Circuit
Figure 15. Zero Crossing Detector Waveforms
