An overview of the modern light dimmer: design, operation, and application

Abstract

The light dimmer is a specialized circuit that utilizes switching techniques to control the brightness of a light fixture. Thyristors (unidirectional semiconductor device) and triacs (bidirectional semiconductor device) are the basic power electronic devices used to control the switching. Once the current crosses the zero-crossing of AC power, the brightness is determined. The sine wave is cut in accordance to the zero-crossing to determine the output power. The light dimmer is an efficient and practical application of power electronic devices in an industrial or consumer product.