Latest Tech News About LED Circuits & Drivers

Fairchild replaces mains LED driver after four months

For reasons I cannot yet fathom from the data sheets, Fairchild has replaced the FL7733 mains led driver chip (July 2014) – at least, it is not recommended for new designs – with the FL7733A. FL7733A is a 5-60W single-stage led driver with primary-side control with <10% THD…

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Take a look at Silan for LED drivers

Chinese chip firm Silan makes several series of mains and low-voltage LED drivers. SD650x high-voltage linear SD660x mains isolated SD670x mains non-isolated SD690x mains non-isolated with PFC SD680x mains isolated with PFC These include: SD6904S with integrated 90V-265V 4N60 mosfet and “the only small SOP…

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Two pin crowbar protects from open circuit strings

For protecting drivers when an LED goes open circuit, NUD4700 from On Semi is a 2x4mm electronic shunt, claming to clamp to 1V in what looks like less than 100ns, according to the data sheet. As well as protecting the driver, it will keep the rest of a string of…

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Dimmer backgrounder for LED bulb designers

If you need to learn about dimmers, IWatt presented a very useful paper at APEC 2011 – Adaptive Chopping Circuit for Retrofit Dimmable LED Driver. The presentation includes an excellent introduction to ‘good’ and ‘bad’ dimmers – the waveforms in the picture are from a ‘bad’ one – and what they do to…

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NXP dimmable controller for 12Vac LED bulbs

NXP Semiconductors has announced a phase-cut dimmable single-stage controller for LED bulbs using 12Vac power: MR16 AR111, for example. Called SSL3401, it is claimed to work “with over 80% of the most common dimmers-transformers combinations”, and to dim “below 5% of maximum light output in most common…

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More on iWatt's chip for low-cost dimmable LED light bulbs

See this article for more general information. iWatt has put an awful lot of work into dimmer compatibility into its latest ac-dc converter for LED replacement light bulbs. The chip is almost entirely digital, and has no microcontroller. Instead, control is implemented in state-machines, which the firm’s…

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OMC introduces a range of Spectralux light engines

Cornwall-based OMC has introduced a range of light engines for LED luminaries, called Spectralux, writes Steve Bush. “Spectralux light engines allow customers to concentrate on what they do best – creating and taking innovative and appealing products to market – using efficient, reliable and cost-effective LED assemblies that have a…

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