FPGA-based phase control for indoor light regulation

Abstract

Automation can be described as a device controlling a process without human assistance. Home automation is the future, where a person may remain comfortable and do tasks effortlessly. Nowadays, technology has improved the efficiency of automation circuitry. In this scenario, the subject is ambient light in a room where, with appropriate control, light inside a room may be adjusted to the user’s desires. Smart Glass is used, mainly focusing on polymer dispersed liquid crystal (PDLC) film, to maintain the user’s required illumination level using sunlight, while if outdoor lighting is insufficient, a lightbulb inside the room will switch on to accommodate the user. Controlling the Smart Glass uses minimal power, averaging about 5W/m2, which may be more economically and environmentally friendly than lighting a room with light emitting diode (LED) lightbulbs. Phase control on the film and lightbulb may be performed to manage the average power delivered to these devices, using a triac. Delaying the trigger pulse to its gate will manipulate the alternate current (ac) voltage wave passing through the device, which results in less power being delivered to the load. The main controller adopted is a Field- Programmable Gate Array (FPGA), which takes care of all operations, including sensor reading and phase control. The user additionally controls the lighting inside a room through a smartphone application, while automation is used to keep the illuminance as requested by the user. Results demonstrate that the project is a success, and the light to be controlled is no more than about 2000 lux. This limitation is attributed to the smart glass technology used, but the project is proof of a concept which can be adapted to other technologies, which may be more suitable for exposure to greater illuminance.