Zero crossing detection using Schmitt's trigger to determin frequency of sinusoidal wave (AC THREE FASE)

[simela]

Hello,  🙂

I'm trying to understand Zero crossing detection using Schmitt trigger, and also how to determin frequency of sine wave. Can someone explain me a parts of .vi i'm using as example, waveform is transferd from FPGA to Host(RT) with DMA FIFO, and it is transformed in 1D Wfm SGL. The part that i dont understand is when 1d array hits Scope View with Trigger for noisy square wave.vi (provided in attach) what's going on in there with signal, and how did we determin frequency. Also trigger method how does it work.

Thank you in advance,

Simela

[tolltroll]

Hi Simela,

The trigger VI takes an input waveform and a threshold level, and outputs an index of where the waveform crosses that threshold. It seems that the Scope View with Trigger VI interleaves components of the voltage and current waveform that have crossed the threshold and outputs the result.

Where is your waveform coming from, and what do you intend to do with the frequency data? What is your application?

Nick

Applications Engineer