LEDs driven by AC without transformers or rectifiers
Published version
Peer-reviewed
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Repository DOI
Type
Article
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Authors
Hughes, Robin W.
Warner, Mark
Abstract
Abstract: We explore the driving of LEDs by untransformed AC. An extreme case is driving 1.9 V threshold (red) LEDs with UK mains, peak voltage 325 V. Commonly, driving is by transformed, rectified (DC) supply with a series resistor (where a significant fraction of the power is wasted) to limit current in the LED. With AC, one can instead reactively limit to a maximum current safe for an LED by employing a series capacitive impedance. Cheaper and simpler supplies can thus be employed in some cases. We analyse such non-linear circuits, and also explore questions of duty cycle and power experimentally.
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Keywords
Article, /639/766/25, /639/166/987, article
Journal Title
Scientific Reports
Conference Name
Journal ISSN
2045-2322
Volume Title
11
Publisher
Nature Publishing Group UK
Publisher DOI
Sponsorship
Department for Education, UK Government (Isaac Physics, Isaac Physics)
Engineering and Physical Sciences Research Council (EP/P034616/1)
Engineering and Physical Sciences Research Council (EP/P034616/1)