Development of Web Based AC Dimmer Using LabVIEW

This paper presents the development of web based AC dimmer using LabVIEW for controlling the ambient light intensity. In this paper, a low-cost microcontroller is used as a control card for supplying the digital dimming signals to the bidirectional triode thyristor (TRIAC) based AC dimmer using the National Instruments LabVIEW software. The main objective of this paper is to implement the digitally isolated dimming of the light intensity from both the onsite and remote location using intelligent control of the firing angle delay of TRIAC based AC dimmer. The dimming level signal is transmitted to the low cost microcontroller board either from the capacitive touch sensor or from the virtual instrument software architecture (VISA) driver of LabVIEW software for onsite dimming control of the AC load. The diming signal from microcontroller port are isolated using an opto-coupler and are supplied to the TRIAC based dimmer that controls the dimming of AC load in synchronization with the zero-crossing waveform of AC input supply. In order to felicitate the remote dimming, the dimming signals are supplied from the client computer to microcontroller board using web publishing tool of LabVIEW.