Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

donate to eham
   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Help me select non RFI strip lights  (Read 6682 times)
K6UJ
Member

Posts: 843




Ignore
« on: June 25, 2016, 01:31:50 PM »

I will be putting in strip lights under our kitchen cabinets.  Did some researching through our forum and read that
the LED's can sometimes be a problem.   I was thinking of getting 2 or 3 foot long fluorescent strip lights but thought I would ask the group for recommendations first.  I finally eliminated the noise generators around the house and don't want to add any more.  ( My Makita drill battery chargers generate so much RFI that Makita should
apply for radio broadcast license from the FCC   Grin Grin )

Bob
K6UJ
Logged
KD0REQ
Member

Posts: 1756




Ignore
« Reply #1 on: June 25, 2016, 08:13:43 PM »

we installed a bunch of no-name LED strips this winter. (same Chinese vendor makes them also under the Menards store label.)  I opened one package and hooked up the many-colors flashing control and switching wall wart.  hooked up next to the TransOceanic.  started tuning around.

nasty nasty noises. wide as a mountain.

don't know about the controller, but the wall wart was surely junk.  out it went.  hooked up an analog job from my stash, quiet as a spider.

so I wired them all with analog wall warts, no controller. if the switching wall warts are white and asymmetrical with little vent-like ridges, it's the same one for sure.

the strips have occasionally funny sections now and then, but hey, that's multicolored stuff.  on the strips, you will see chip LEDs and chip resistors for current limiting, no other electronics.  so the strips are your friend.  the rest of it, test one.  if it's nasty, take it back, and tell them it's illegal to use in the US because of radio noise.  use analog power and live stress-free.  make sure it's UL or RU labelled on the wall wart.

oh, the "3M adhesive!"? it's not their permanent stuff.  peel it off and get auto body doublestick tape if you want it to stay in place.  the silicone holders with two screws on these kits are kind of light duty.  cut tangs off the end of white cable clamps and use those.
« Last Edit: June 25, 2016, 08:24:28 PM by KD0REQ » Logged
K6UJ
Member

Posts: 843




Ignore
« Reply #2 on: June 25, 2016, 09:13:34 PM »

I have had no experience with the LED strips.  So the LED strips are OK but the power supply "wall warts" are the noise generators.  I will take a look at what Home Depot has.  They are great with returns if needed. 
Thanks for the informative post !

Bob
K6UJ
Logged
K5LXP
Member

Posts: 4971


WWW

Ignore
« Reply #3 on: June 26, 2016, 06:55:39 AM »

A few years ago before LED's were as prolific as they are now, the popular under cabinet light was halogen.  They suffered the same noisy power supply issues as the current crop of cheap LED supplies.  So I went with xenon puck lights, which are bulbs the size of halogen but run directly off of 120V.  No power supplies to generate noise or have to stash in a wall somewhere, and dimmable with standard dimmers if you like.

LED's today offer a lot of bright light in lots of configurations so they're a compelling choice.  Commercially I've seen some very RF-quiet LED (constant current) supplies so it's possible to have the best of both worlds, but the box stores don't have the greatest reputation for selling products from reputable sources.  You may luck out with try-and-buy or pay more and go for a more premium product.

Mark K5LXP
Albuquerque, NM
Logged
NK7Z
Member

Posts: 1407


WWW

Ignore
« Reply #4 on: June 26, 2016, 07:15:31 AM »

When you purchase, leave an out for returns...  If they are noisy, (and they will be), return them, and tell the vendor why you are returning them, RFI...  If enough of us do this, the vendors may eventually get the idea RFI is bad...  If you decide to keep them, or can't get a return authorization for them, then be prepared to replace the power supply.  Most supplies are switchers nowadays, and as such they are more than likely to generate RFI...  If you do replace the PS, be sure to let the vendor know as well, again, let them know it is RFI that is the issue...
Logged

Thanks,
Dave
For reviews and setups see: http://www.nk7z.net
KD0REQ
Member

Posts: 1756




Ignore
« Reply #5 on: June 26, 2016, 11:14:27 AM »

where you can't go wrong is buy components off the rack.  buy the strips, the mountings, the power-in adaptor, and if you don't have a bunch of small plastic boxes, the switch.  leave the creepy remote control kits and crappy switching wall-warts behind, just make sure you know the voltage the strip wants (mostly 12 volts, but never assume...)

the LED strips are just reverse-biased diodes and current resistors.  all the actives are suspect in the power system.
Logged
KC2MMI
Member

Posts: 715




Ignore
« Reply #6 on: June 28, 2016, 01:33:40 PM »

Like he said. The LED strips themselves cannot create any RFI, they are just passive components. Power them with an analog wall wart and there's nothing to create RFI. Power them with a "good" digital wall wart, and you may or may not have an RFI issue from that, which the strips will gladly broadcast.

If you put them on any kind of dimmer, as many people do, many of the dimmers are going to create RFI too.
Logged
W9IQ
Member

Posts: 392




Ignore
« Reply #7 on: Yesterday at 04:34:21 AM »

Quote
the LED strips are just reverse-biased diodes and current resistors

This is incorrect. LEDs are current driven, forward biased diodes. And many LED lights now contain switching circuits to regulate the current through the diode. This is particularly true for LED lights that feature a built in dimming or color control mechanism.

- Glenn W9IQ
Logged
KD0REQ
Member

Posts: 1756




Ignore
« Reply #8 on: Yesterday at 11:12:57 AM »

on the strips, that controller is outboard.  look at the light strips.  if all you see is LEDs and resistors, the only way you get RFI out of that is to put it in a powerful beam of RF, and have it frequency-multiplying all over the place.  like, say, point a microwave horn at it.  what does not burn out makes RFI stronger.

it is possible that there are puck or tube light LED setups with a controller in them.  looked like one epoxy gob-spot and a recognizeable chip in the one in my kits.
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!