Where to get LED filaments not already incorporated into light bulbs?

[seanspotatobusiness]

I've seen some YouTube videos of people messing around with LED filaments extracted from light bulbs which use them to look like incandescent filaments. I've read comments that you can get them as just the filaments themselves, without having to break open glass bulbs but when I search all I get are the complete bulbs. Does anyone know what search terms will find just the filaments sans bulb? Do they have some kind of name other than just "LED filament"? Thanks.

 

[jtr1962]

Loads of them on eBay or Aliexpress. Just do a search for LED filament DIY or LED filament COB. You'll get lots of filament bulbs also showing up in the search but there are plenty of people selling these, mostly from China.

 

[Dave_H]

Filaments found in ac bulbs are series-connected with forward voltage typically around 75v (a couple
dozen per filament). Ones used in small flashlights, worklights, and solar garden lights etc.
are parallel-connected, so can run from low voltage without a boost circuit which could simplify
some designs.

Dave

 

[seanspotatobusiness]

Okay, thank you both.

 

[Dave_H]

I'll add a few points.

Low-voltage flashlights and worklights sometimes use COB LEDs but generally not filament.

The small solar garden light I have uses a 14-LED filament, parallel-wired as I measured 2.5v dc on its leads
(reasonable at low intensity).

Keeping an eye on filament LED products in addition to ordinary ac bulbs, I have seen line-powered
patio bulbs, 1W 50 lumen with a single filament. This does not mean it is directly powered from the
line voltage (converted to dc of course) as the bulb electronics are not known in this case (just looking
at in-store products). Not very good efficacy though, as other filament bulbs can easily get to 100 lumens/W
and higher. I also see patio lights powered by 24v dc so that voltage variant exists.

Lastly, I found a construction article for Arduino-based digital clock with large filament LED display.
It uses 80v dc supply which jives with the 75v series arrangement commonly seen in ac bulbs.

https://www.instructables.com/Charlottes-Web-Style-LED-Filament-Clock/

Dave

 

[PhotonWrangler]

That filament clock is a beautiful mix of steampunk and modern technology.

 

[Dave_H]

Loads of them on eBay or Aliexpress. Just do a search for LED filament DIY or LED filament COB. You'll get lots of filament bulbs also showing up in the search but there are plenty of people selling these, mostly from China.

I notice in a couple of eBay listings the words "solar 3v" denote low-voltage filaments, to differentiate from series-connected high-voltage types.

My "source" of high-voltage filaments was dropping a small glass bulb. The shell broke but the filaments inside were intact. That's when the voltage was measured using clip leads, with caution.

Dave