It can also be used as phase meters, as it can be used to measure the phase angle between two voltage applied at its terminals. Zero Crosssing Detector is a form of comparator that can detect zero crossing of ac input signal. In this article you will get to know about the circuit diagram and working of zero crossing detector.
D. Zero-Crossing Detection by Interpolation The implementation used in this design identifies two points on the sine wave: the first just before the positive going zero crossing and the second just after the same zero crossing.
The net result is an accurate measurement at the expense of slow measurement rates. Zero crossing is the point of choice for measuring phase and frequency. The reference is usually easy to establish and the signal’s amplitude rate of change is maximum at signal zero.
Zero crossing is the point of choice for measuring phase and frequency. The reference is usually easy to establish and the signal’s amplitude rate of change is maximum at signal zero. Phase synchronized triggering requires placing additional constraints on zero crossing detection.
Signals can be filtered before passing through the zero crossing detector provided that they meet the constraints previously described. Noise, on the other hand, is generally broad band and frequency filtering alone is insufficient to reduce detecting multiple zero crossings per half period.
A Zero crossing detector detects zero-crossing points of AC signals to provide timing pulses, whereas a PLL is used to lock onto a signal’s phase and frequency. Zero crossing detector is a simpler circuit, while PLLs offer more precise frequency and phase control.