[Elecraft] Dimmable LED desk lamp for operating position recommendation needed

[David Woolley]

There will be a switching converter on any quality make of LED lighting. 
  The only way you avoid it is if they use a simple series dropper 
resistor, which is not energy efficient.

LEDs are constant current devices, so there is no such thing as a 12V 
LED (an LED with a 12V forward voltage drop would be well into the far 
ultraviolet, and would still need current regulation).

Professional installations would use a switching constant current supply 
(typically called a driver).  Those for amateurs and the average 
building contractor would mimic tungsten bulbs by having a constant 
current switching regulator in each bulb.

Some cheap mains operated lamps use capacitive droppers followed by 
rectifier and resistive current limiter.  They are the type likely to be 
sold in one dollar stores, or on Ebay.
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On 06/01/17 11:50, Marc Veeneman wrote:
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>> On Jan 6, 2017, at 2:00 AM, Peter D. Vouvounas <wb3fsr at comcast.net> wrote:
>>
>> I presume some of you have been through a selection process to find a usable
>> dimmable LED desk lamp with articulating arm that does not create RFI back
>> into your Flex on HF.
>>
>>
>
> I mounted (dual side adhesive tape) an LED strip to the underside of an equipment shelf.  The strip came with a 12v switcher that I ignored.  I use my 12 volt supply.  The strip was, I think, 24 inches long and has a dimmer that can be inserted in the power lead.  No RFI.  Plenty bright.  Mine came from Amazon but there are many to choose from these days; you can even select color temperature when you order.
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