The ZMPT101B is a compact, high-precision AC voltage sensor module tailored for single-phase systems, offering galvanic isolation and safe interfacing with microcontrollers like Arduino, ESP8266, or Raspberry Pi. At its core is a miniature ZMPT101B voltage transformer that steps down and isolates hazardous mains voltages (up to 250 VAC). The onboard precision op‑amp circuitry amplifies and conditions the stepped-down signal, producing a stable analog output (typically 0–5 V DC) proportional to the input voltage. A trimmer potentiometer allows fine-tuning of that output for calibration and accuracy. Designed for non-intrusive measurement, this sensor ensures consistent, accurate readings while protecting low-voltage electronics. It accepts a DC supply voltage between 5 V and 30 V and handles an operating temperature range from –40 °C to +70 °C (or sometimes 40 °C to +70 °C, depending on the manufacturer). The board measures approximately 50 mm × 19 mm and weighs around 20–26 g, making it PCB-friendly and easy to integrate into tight layouts. Ideal for DIY voltage monitoring, power management systems, smart home projects, and industrial automation, the module combines safety, accuracy, and convenience—perfect for embedded applications requiring reliable AC voltage sensing without directly exposing sensitive electronics to mains power.