Examine an LED bulb and you are likely to find the LEDs on board are phosphor-converted white LEDs (PC-LEDs). These are created either from blue- or near-ultraviolet-emitting chips emitting light at about 450 nm that are coated with a yellow phosphor. The phosphor down-converts the light output into lower visible light frequencies. PC-LEDs that operate […]
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What’s all this stuff about capacitive power supplies for LEDs?
A while back a viewer of our 60-W LED bulb teardowns posted a comment about the complexity of the power supplies found in the bases of these bulbs. We talked about some of the reasons these bulbs contain switching supplies in a previous article. But our latest post elicited this comment from another reader: Well, […]
Why do we need all this LED driver stuff, anyway?
The late Bob Pease, a venerated and well-liked engineer at National Semiconductor Corp. (now part of Texas Instruments) once wrote a series of technical musings inspired by questions that mostly younger engineers had to put to him somewhere along the line. We thought back to how Mr. Pease might have reacted when we noticed a […]
