Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > General Electronics Technical Discussion
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 09-21-2021, 09:41 AM   #1
eccerr0r
Solder Sloth
 
eccerr0r's Avatar
 
Join Date: Nov 2012
City & State: CO
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 6,367
Default line powered filament LED lamps...

I was playing with one of those "filament" LED lamps. I noticed it seemed to flicker a bit...so I tried powering it with different things to try to extract information about it - noticed it seems to be 100% LED - no droppers, no PSU, no rectifiers, nothing - the LED "filaments" are hooked straight to the contacts!

Wondering what's the distribution of how "filament" LED lamps are driven? Do any have capacitive droppers? rectifiers? CC PSUs?

---

Found another "filament" LED that does have a PSU in it, seems to be a capacitive dropper type, possibly CC as well. Runs better than the first one - does not flicker.

---

On another note, found a little multichip LED (has 24 1206(I think) SMT LEDs in it on two crossed PCBs) all in a unit about 1" long and ⅜" diameter (12VAC/DC, about 1W dissipated) that contains its own tiny switching PSU in it, can see a SOT23-5 IC(?) and a coil in it, and of course rectifier diodes. All embedded in silicone. Wonder how much these cost to make...

Last edited by eccerr0r; 09-21-2021 at 10:04 AM..
eccerr0r is offline   Reply With Quote
Old 09-21-2021, 10:59 AM   #2
PeteS in CA
Badcaps Veteran
 
PeteS in CA's Avatar
 
Join Date: Aug 2005
City & State: San Jose, CA
My Country: USA, Unsure of Planet
Line Voltage: 120VAC, 60Hz & 115VAC, 400Hz
I'm a: Professional Tech
Posts: 3,235
Default Re: line powered filament LED lamps...

With traditional incandescent light bulbs, brightness is average voltage dependent. LED brightness is current dependent.

Hooking a simple series string of LEDs across the line would result in an uncontrolled current and therefore uncontrolled brightness. And since LEDs are diodes, conduction would only occur on the appropriate half cycle. Or so it would seem to me.

At the other extreme of LED lighting, LED street lamps are driven by a switching power supply that regulates output current rather than output voltage.
__________________
PeteS in CA

Power Supplies should be boring: No loud noises, no bright flashes, and no bad smells.
****************************
All that is gold does not glitter,
Not all those who wander are lost;
- J.R.R. Tolkien, The Fellowship of the Ring
****************************
To kill personal responsibility, initiative or success, punish it by taxing it. To encourage irresponsibility, improvidence, dependence and failure, reward it by subsidizing it.
****************************
Laughable prediction, https://principia-scientific.com/doc...l-most-people/ ; Fully Vaxxed May 2021; Viva CallSJ "5K" (actually 3.26 miles), 9/19/21, 51:19; Belmont Water Dog 10K, 10/9/21, 1:52:45; 11.8 miles, 3:50:16, 9/4/21
PeteS in CA is offline   Reply With Quote
Old 09-21-2021, 01:47 PM   #3
eccerr0r
Solder Sloth
 
eccerr0r's Avatar
 
Join Date: Nov 2012
City & State: CO
My Country: USA
Line Voltage: 120VAC 60Hz
I'm a: Hobbyist Tech
Posts: 6,367
Default Re: line powered filament LED lamps...

I'd imagine street lights, since aesthetics doesn't matter too much, use standard high reliability LEDs. I suspect that the LEDs could then be binned unlike "filament" LED strips.

The first "filament" LED seems to contain two sets of LEDs in inverse paralled to deal with AC.
eccerr0r is offline   Reply With Quote
Old 09-22-2021, 11:03 AM   #4
Per Hansson
Super Moderator
 
Per Hansson's Avatar
 
Join Date: Jul 2005
City & State: ----
My Country: Sweden
Line Voltage: 230v 50Hz
I'm a: Knowledge Seeker
Posts: 4,842
Default Re: line powered filament LED lamps...

Big Clive makes lots of videos on LED lights, just browse through or search and you will find several on filament LED's too

https://www.youtube.com/c/Bigclive/videos
__________________
"The one who says it cannot be done should never interrupt the one who is doing it."
Per Hansson is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2021
Powered by vBulletin ®
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 08:06 PM.
Did you find this forum helpful?