Imported from GitHub: zoftko/pcrap · commit 59ce903 · license BSD-3-Clause

Description

Printed circuit board designs (KiCad)

README

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title: Zero Cross Detector brief: This board features a common circuit found in application notes for the LM393 comparator. It detects zero crossings on AC signals.

zcd393

This is a zero cross detector which produces a square wave whose polarity changes whenever the AC signal fed to it crosses the zero voltage line. The schematic used in this circuit can be found in application notes from different manufacturers and on "Motorola's 1993 Linear Interface ICs".

Component values may be changed to work with different voltage levels. The values in this iteration were chosen and tested for 12V AC signals. In theory, with the proper voltage divider, this circuit should work with mains voltage, just be sure not to electrocute yourself. I personally preferred to use a 120 to 12V transformer.