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thender
Screen tycoon
Premium
join:2009-01-01
Brooklyn, NY
kudos:1

Ignorant LED lighting question.

»cgi.ebay.com/ws/eBayISAPI.dll?Vi···15659017

I thought LEDs worked off of DC power - how is it this is rated to work with 100-240 VAC? Is it a special LED that works off of AC? Does it have a power supply inside of it? is it just an error.

I figured since it said 100-240VAC it would be a drop in replacement for a fluorescent fixture without much modification required.
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shdesigns
Powered By Infinite Improbabilty Drive
Premium
join:2000-12-01
Stone Mountain, GA

LED light assemblies have rectifiers and filter caps to convert to DC then a switching regulator to control power.

I would imagine you would need to remove the ballast and wire to 120V to use the bulbs.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
kudos:1

1 edit
reply to thender

said by thender:

I thought LEDs worked off of DC power - how is it this is rated to work with 100-240 VAC? Is it a special LED that works off of AC? Does it have a power supply inside of it? is it just an error.

FYI there are actually a few "AC-LEDs" that operate directly from AC line voltage ... but majority of AC LED lamps use what is called an "off-line" LED driver IC.

Good example: »www.linear.com/products/offline_led_driver
The LT3799 is an isolated LED controller with active power factor correction (PFC), specifically designed for driving LEDs from a universal input range of 90VAC to 265VAC

*** I could not check that particular eBay item (URL asked me to log in first) but cheap no-brand LED lamps may have poorly designed AC-DC conversion stage using low-cost discrete components.