General > General Technical Chat
LED Christmas lights - love 'em or hate 'em?
<< < (10/15) > >>
S. Petrukhin:

--- Quote from: james_s on November 27, 2020, 10:25:17 pm ---
I find that I can see the visible flicker when using a diode on incandescent though even at 60Hz, I'd imagine it must be much worse on 50Hz, and also it drops the power down enough to be noticeably dimmer.


--- End quote ---

Can you see interference with another light source flashing slightly with a phase shift?
S. Petrukhin:

--- Quote from: 25 CPS on November 27, 2020, 10:48:22 pm ---I'm curious, does anybody know what the utility companies position on LED lighting is?  I remember reading about a 1970s TV regulated power supply circuit that introduced a nonlinear current waveform that caused some issues in places where it was in common use at the same time of day so I was wondering if LED lighting, Christmas or otherwise, being a nonlinear load has been a problem or at least something that's noticeable from the electricity utility end?

--- End quote ---

I think the led load is not so large that it is noticed by the power company. Although, in the modern power supply network there are so many pulse consumers that the sinusoid has long been bitten off by the tops.
james_s:

--- Quote from: madires on November 28, 2020, 12:45:26 pm ---So far I've seen LED fairy lights with some sort of controller powered only by a small SMPSU wall wart. Half the LEDs in the string are wired in parallel, and the other half anti-parallel. The controller generates a PWM and also switches the polarity to select which half of LEDs to light. Usually they have 8 modes.

--- End quote ---


I think that's probably due to regulations in some 240V countries. Here in the US transformer powered miniature lights were never really a thing, they were always just series strings of lamps fed directly from the mains, when LED strings appeared they used the same arrangement with the addition of a ballast resistor. Some have sections wired in anti-parallel to reduce flicker, some don't. More recently I've seen some multi-mode lights that have electronic controllers but there are still a lot of the plain series string LEDs.
VK3DRB:
What has LED lights got to do with the birth of Jesus Christ? Nothing whatsoever.


james_s:

--- Quote from: VK3DRB on November 29, 2020, 03:19:21 am ---What has LED lights got to do with the birth of Jesus Christ? Nothing whatsoever.

--- End quote ---

Virtually none of the Christmas traditions have anything at all to do with the birth of Jesus, but that's beside the point. Many elements were borrowed from existing Pagan holidays, some are much more recent than that. Santa's red & white suit came from a Coca Cola advertising campaign, Rudolph the Red-Nosed Reindeer was an advertisement for the Montgomery Ward department store chain.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod