Virtual Booth

This project reports the design and development of an Automatic Power Cut-Off Socket intended for residential college room usage to reduce risks associated with electrical overload. In dormitory environments, multiple appliances are frequently connected to a single socket or extension outlet, which can increase the likelihood of overheating, equipment damage, and electrical safety incidents when the total load exceeds a safe operating limit. The objective of this project is to monitor load current in real time, estimate the operating power, and automatically disconnect the supply when the power exceeds a preset threshold of 1000 W, while providing clear feedback to the user. The prototype is implemented using a NodeMCU ESP8266 microcontroller, a YHDC SCT-013 (30A/1V) split-core current transformer for non-invasive current measurement, a relay module for switching the live line, and a 16×2 I2C LCD for displaying measured values and system status. The controller samples the conditioned sensor waveform through the ADC, applies offset tracking and RMS computation to obtain Irms, and estimates power using P ≈ 240 V × Irms. To enhance operational reliability, the control algorithm applies anti-spike logic by requiring consecutive readings above the threshold before tripping, and incorporates cooldown and stable-reset conditions to prevent rapid cycling and to restore supply only after the load is removed. Experimental verification using various electrical loads indicates that the plug remains ON under normal conditions and successfully performs automatic cut-off when the estimated power exceeds 1000 W, with real-time display of Power (W), Current (A), and ON/OFF status. The main limitation is that the power value is estimated without voltage sensing and power factor measurement, which may affect accuracy for non-unity power factor loads. Future improvements may include true power computation through voltage sensing and additional monitoring features to strengthen safety and usability.