Isolated AC mains Voltage Detection Module

Description

Isolated AC mains Voltage Detection 5V and 3.3V output level compatible Overview The AC 220V Mains Voltage Sensor Module is a safe and isolated detection board designed to sense the presence of AC mains voltage (110V–250V).It provides a logic-level signal output suitable for microcontrollers such as Arduino, ESP32, STM32, or Raspberry Pi to detect whether mains power is present or absent. The module features optical isolation using the PC817 optocoupler and includes an onboard LED indicator for visual power status feedback. Features Safe isolation from high-voltage AC mains Onboard LED indicates when mains power is detected Optocoupler isolation (PC817) for MCU protection Wide input range: 110–250V AC compatible Logic-level output (3.3V or 5V) for direct connection to microcontrollers Compact design with screw terminals for easy wiring Galvanic isolation ensures no direct connection between high-voltage and low-voltage circuits Designed for DIY, automation, and power monitoring projects Technical Specifications Parameter Specification Input Voltage (AC IN) 110V – 250V AC Isolation Type Optocoupler (PC817) Output Voltage (Signal) 0V (no AC) / HIGH (AC detected) Output Logic Voltage 3.3V / 5V compatible Indicator LED Lights when mains AC is detected Filter Capacitor 47µF electrolytic capacitor Rectifier Diode Bridge rectifier (B5) for AC polarity protection Fuse/Resistor 47KΩ or 68KΩ, 1W high-voltage resistor Optocoupler Drive Current ~3–5 mA typical Operating Temperature -10°C