Review on SMAKN® Voltage Transformer Module Active by Wayne Espinoza

This module works but it has no specs, no paperwork, no specs, not even from the manufacturer LC Technology, so I am deducting a star because I had to waste time clarifying it. To save you the headache, the bottom line is this: if you connect the green terminal L to mains and N to neutral from a 120V/60Hz source, the module outputs a DC waveform of 60Hz relative to it Vcc off. Vcc can be between 3.3 and 5V DC. At 3.3 VI the wave rises and falls between about +1.35V and +0.9V. So if you take a lot of samples per second you can analyze the waveform and get the actual voltage. Turning the potentiometer clockwise decreases the amplitude. For a LUA example, search "using nodemcu with zmpt101b" on ESP8266. On Arduino you can use EmonLib to sample and calculate the voltage. I chose this one because other AC modules in this price range can't handle more than 30V or 50V and making a module with an AC to AC converter would be time consuming and cumbersome.