Filament LEDs - How are they connected inside? - Page 1
Forum section: electronics / general

author: xrunner
author_rank: Super Contributor
timestamp: January 26, 2025, 01:52:30 pm
content: Like these -Filament LEDsI was thinking abut integrating some of these inside some 3D prints, but I want to know more about how to power them. I have searched for an explanation but I can't seem to find aclearanswer.Some places say there are many LEDs connected in series but that can't be strictly true. I see some of these filaments running off a single 3V battery and if each LED has ~2.5 to 3V drop it can't be powered like that because there isn't enough voltage from one 3V battery. Does anyone know how these filaments have the LEDs internally designed or connected? The EEVBlog is the go-to place for the answer.Thank you.

author: themadhippy
author_rank: Super Contributor
timestamp: January 26, 2025, 02:00:13 pm
content: Is it led or is it el (electroluminescent) wire?

author: Marco
author_rank: Super Contributor
timestamp: January 26, 2025, 02:24:21 pm
content: Filament LED is the high voltage short filaments they put in bulbs, they are just LEDS in series. Neon LED tape is LED strip with a coloured diffusing layer, with repeating sections running off some type of busbar running the length. BigClive has a lot of videos on various incarnations. EL wire uses barrier discharge in between some twisted insulated wires (could be parallel too if you manufactured it like that) to excite a phosphor, they don't tend to be very efficient or last very long. Not sure if the Amazon stuff is really EL wire or just very flexible LED tape.BigClive also has a couple of videos on 3D printing shapes to put Neon LED tape in, with scripts you can download, that seems to be most appropriate for your project.

author: PA0PBZ
author_rank: Super Contributor
timestamp: January 26, 2025, 02:25:32 pm
content: The listing says battery powered, 3V 3W, 60 light sources, seems about right.

author: Zero999
author_rank: Super Contributor
timestamp: January 26, 2025, 02:42:27 pm
content: They appear to be EL wire, not LED. The description says the control box makes a buzzing sound between 1kHz and 2kHz, which is typical of an inverter which boosts the 3V from the batteries to 100V AC.There's no need to build your own power supply, just buy one off the shelf.

author: xrunner
author_rank: Super Contributor
timestamp: January 26, 2025, 02:52:41 pm
content: Quote from: themadhippy on January 26, 2025, 02:00:13 pmI'm talking about filament LED. I'm sorry that original listing has confusing language mixing EL and LED.Let's start over. I'm talking about this part -Filament LEDSo back to my question then. Some places say there are many LEDs connected in series but that can't be strictly true. I see some of these filaments running off a single 3V battery and if each LED has ~2.5 to 3V drop it can't be powered like that because there isn't enough voltage from one 3V battery. Does anyone know how these filaments have the LEDs internally designed or connected? The EEVBlog is the go-to place for the answer.

author: Marco
author_rank: Super Contributor
timestamp: January 26, 2025, 02:58:45 pm
content: Quote from: xrunner on January 26, 2025, 02:52:41 pmGuess they make some filaments specifically for hobbyists with busbars instead of series connected LEDs.Those will not be the ones they use in any mains voltage bulb, because having series LED strings run near mains peak voltage has been the greatest cost savings in LED lighting ever.

author: Haenk
author_rank: Super Contributor
timestamp: January 26, 2025, 04:07:13 pm
content: Quote from: xrunner on January 26, 2025, 02:52:41 pmIf I remember BigClive correctly, there are different ways of connecting them, some are serial and parallel connected, dependent on the voltage the manufacturer wants to reach.For DIY usable parts, it is probably best to get low voltage lamps, a 230V lamp with a single filament is probably constructed with LEDs in series only (i.e. you will need the 230V).

author: xrunner
author_rank: Super Contributor
timestamp: January 26, 2025, 04:42:02 pm
content: Quote from: Haenk on January 26, 2025, 04:07:13 pmAccording to the articles I found the LEDs are "microscopic". So I was looking for a picture of the physical way they are connected inside the coating they have over them. I'll keep looking for that.

author: Zero999
author_rank: Super Contributor
timestamp: January 26, 2025, 05:35:49 pm
content: Quote from: xrunner on January 26, 2025, 02:52:41 pmThose are LEDs. Presumably they can run directly off 3V.

author: watchmaker
author_rank: Unknown
timestamp: January 27, 2025, 01:26:25 pm
content: OOOH. I think they are what I purchased on Ali.https://www.aliexpress.us/item/3256805523639808.html?I use them for lighting the dials of linear tuning indicators on vintage battery radios. They are great.You can cut them any place and scape down to the traces to solder. Yes 3VDC is all they want. The colors are very good (Iuse the green or blue).

author: Xena E
author_rank: Frequent Contributor
timestamp: January 27, 2025, 04:42:40 pm
content: The "filaments" are manufactured internally connected as required. Ive bought some in the past that are parallel connected, mounted inside a GLS style bulb and run from an internal 18650, there is no step up inverter. Just the "filaments" a battery, switch, usb charge socket and hanging hook.Sure Big Clive did a video on them.Poundland (UK) were selling them as camping lights at one point.Therefore the individual "filaments" could easily be genuinely available.Regards,X