# LED Dimming?



## travis13 (Oct 12, 2012)

Just curious how LED can lights or any dimmed lights work with the two control wires going to the driver. What is actually happening to dim the lights?


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## Black Dog (Oct 16, 2011)

travis13 said:


> Just curious how LED can lights or any dimmed lights work with the two control wires going to the driver. What is actually happening to dim the lights?


What voltage?


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## running dummy (Mar 19, 2009)

That's 0-10 v dimming. A separate signal is sent to the driver that is literally anywhere from 0-10v, depending on what you have the switch set at. 

If its at 2v then it's somewhere around 20% dimmed,and so forth throughout the 10v spectrum.


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## running dummy (Mar 19, 2009)

running dummy said:


> That's 0-10 v dimming. A separate signal is sent to the driver that is literally anywhere from 0-10v, depending on what you have the switch set at.
> 
> If its at 2v then it's somewhere around 20% dimmed,and so forth throughout the 10v spectrum.


The driver interprets the 0-10v signal and works its magic within the driver to dim the load.


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## randolph333 (Feb 10, 2015)

It varies, depending on driver internals.

Here's a series of articles that discuss some driver designs, contributed by IC manufacturer Linear Technologies.

This Google Search brings up tons of stuff, but you'll have to sift through it yourself!


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## randolph333 (Feb 10, 2015)

Here's Lutron's discussion.

Here's Philips.

There's a lot more to be said on driver internals, but this is what dimmers do.


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## randolph333 (Feb 10, 2015)

One of my colleagues from the old All LED site (now defunct, alas) comments:
There are many different topologies, and each has its unique method of operation. Generally speaking, semiconductor manufacturers that build the heart and brain of power supplies (such as Supertex, Linear Technologies, Fairchild Semiconductor) have detailed information on their theories of operation.​
So that's about as much of an answer as I have for you.


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## Electric_Light (Apr 6, 2010)

randolph333 said:


> It varies, depending on driver internals.
> 
> Here's a series of articles that discuss some driver designs, contributed by IC manufacturer Linear Technologies.
> 
> This Google Search brings up tons of stuff, but you'll have to sift through it yourself!





randolph333 said:


> One of my colleagues from the old All LED site (now defunct, alas) comments:
> There are many different topologies, and each has its unique method of operation. Generally speaking, semiconductor manufacturers that build the heart and brain of power supplies (such as Supertex, Linear Technologies, Fairchild Semiconductor) have detailed information on their theories of operation.​
> So that's about as much of an answer as I have for you.


Not everything sold by LED sites are legal. Some are definitely illegal(utterly outside of FCC regulations or a shameless unambiguous patent infringement that would get stopped by a court order if a major supply house was to offer them) some are only a light shade of grey depending depending on how hard big players like CREE flex their legal muscle in making patent infringement claims.


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## randolph333 (Feb 10, 2015)

All LED was a Philips promotional site; didn't sell anything at all. It had a good crowd of bloggers.


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## randolph333 (Feb 10, 2015)

A little more graphical explanation from (who else?) Lutron:
http://www.lutron.com/TechnicalDocumentLibrary/048360a_PWM_vs_CCR_LED_App_Note.pdf​


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## Electric_Light (Apr 6, 2010)

randolph333 said:


> All LED was a Philips promotional site; didn't sell anything at all. It had a good crowd of bloggers.


Some Philips LED linear lamp LM79 data laboratory tests are conduced at a Chinese lab. I question the quality legitimately so, because there are a ton of errors and procedural discrepancies. 

CREE's product portfolio manager has done their share of gibberish spurting too.


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## NacBooster29 (Oct 25, 2010)

Electric_Light said:


> Some Philips LED linear lamp LM79 data laboratory tests are conduced at a Chinese lab. I question the quality legitimately so, because there are a ton of errors and procedural discrepancies.
> 
> CREE's product portfolio manager has done their share of gibberish spurting too.


These leds are just a fad I guess...
Same with email, and the internet, those things will never catch on.

Seriously Mr. Electric light, you seem to keep preaching. But frankly your gripes although well stated and thought out, don't seem to be slowing down the inevitable.


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