[RFI] QRM from recessed lighting

[Jim Brown]

On 11/15/2021 7:16 PM, Lloyd - N9LB wrote:
> When making your own analog power supply for LED lighting, remember that the
> LEDs need Regulated Current ( not regulated voltage ).
> You can use a regulated voltage, but you must include a current limiting
> circuit or series resistor.
> You can measure the current being drawn from the switching power supply by
> the LED lighting and then use that number for designing your homemade analog
> power system.

This reseller has exhibited at western and southwest ham conventions for 
quite a few years. This page lists some very useful LED lighting 
products that can be "home brewed" to put lighting on ceilings and under 
shelves. Most include the required current limiting. I've made effective 
use of the lighting strips with a metal frame that easily attaches to a 
wood surface and wired in series from an end feed, and the strings of 
lights on rolls that can be cut to any desired length and fed from one
end. Both are designed to run from 12V DC, both come warm or cool white.

https://www.wiredco.com/LED-Lighting-Low-Voltage-s/1874.htm

https://www.wiredco.com/SMD-Flex-LED-Warm-White-Light-Strip-16ft-5-meters-p/flexibleledwarmwhite.htm

https://www.wiredco.com/LED-Strip-Light-12-Volts-SMT-Cool-White-20-p/ledbar1.htm

I'm using four of these strips attached to the ceiling of my shack, and 
a 12-15-in length of the flexible strip on the underside of a shelf over 
the computer keyboard. W6GJB lit his 2-operator contesting trailer with 
a lot of the flexible strips glued to the ceiling. We're both running 
our lighting from float-charged 12V SLA batteries that run our gear. The 
lighting in my shack, which is not super bright but very nice for 
operating, draws a bit more than 1A. Glen's trailer is a LOT brighter, 
so pulls more power.

They also sell a simple in-line switch that I'm using in the shack.

I would be cautious about his power supplies, which are identified as 
switch-mode, so are likely to be mondo-noisy. Although he sells at ham 
events, I didn't get the impression in talking to him that he's a ham or 
even slightly technical. Most of the other stuff he sells is pretty cheesy.

I'm planning an under-cabinet light for the kitchen, and will run it 
from a vintage linear wall wart -- I have a large stash of them to 
replace the switchers that come with equipment.

73, Jim K9YC