Single Supply Zero Crossing Detector With LM339

This scheme is called Zero-crossing detector using LM339, in principle, be used to convert without waves or other signals into square-wave, the output should be low if the input is negative, and if high if the positive feedback. Many zero-crossing detector using split supply (supply symmetrical), but this zero-crossing detector circuit requires only one supply, so suitable for battery-operated circuits.




schematic diagram source: Motorola Application Notes