What is the part number of coaxial DC cable in laptop AC adapters? - Page 1
Forum section: electronics / beginners

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 26, 2024, 09:09:23 pm
content: Hello.Laptop AC adapters use a special DC cable - it is coaxial and rated for currents up to 10A for certain laptops, while being relatively thin and flexible.I need such DC cable, but can't find it on digikey, ebay or whatsoever - for sure, there are sold replacement DC cables for all kind of laptops, but, with a fixed length, while I'm looking for a longer piece of such cables, say, I'd buy a whole 100ft roll, , and without any DC plugs on the ends (I'll add my own)Any ideas?

author: thm_w
author_rank: Super Contributor
timestamp: July 26, 2024, 10:19:19 pm
content: I think the coaxial part is more for shielding and less for flexibility.So you could use any old two core cabling as well.Can you determine the AWG or mm2 sizing that you need?

author: CaptDon
author_rank: Super Contributor
timestamp: July 27, 2024, 01:42:13 am
content: I think that 10 amps is a peak and not continuous rating. Most laptop supplies come in at around 19vdc at around 4 amps average. Even that is nearly 80 watts. Check the Alpha or Belden online wire catalogs.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 27, 2024, 04:15:40 am
content: Big, gaming laptops often come with 200W and 300W power supplies and they're usually around 20V 10-15A and higher.Can't find anything within Belden's page.

author: tooki
author_rank: Super Contributor
timestamp: July 27, 2024, 09:07:21 am
content: Quote from: LinuxHata on July 26, 2024, 09:09:23 pmOne tip: don’t look for “coaxial” cable. What I mean is that the phrase “coaxial cable” is almost always used to refer specifically to controlled-impedance cables commonly used for RF,to the exclusion of other cables whose construction is of a co-axial nature,like shielded cables for audio or power. So even though your shielded DC power cable is co-axial in construction, it’s not considered “coaxial cable”.Instead, look for “shielded” cable or wire.

author: tooki
author_rank: Super Contributor
timestamp: July 27, 2024, 09:16:26 am
content: For example, look at this DigiKey search:https://www.digikey.ch/short/vcntjpwf

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 28, 2024, 07:18:46 am
content: Thanks!Never thought that they would put them into "jumper wire" categoryNow I need to find the name for such cable in China, to avoid aerospace grade pricing @ DigiKey

author: tooki
author_rank: Super Contributor
timestamp: July 28, 2024, 10:45:53 am
content: Quote from: LinuxHata on July 28, 2024, 07:18:46 amUmmm… well they didn’t? “Jumper wires” are a separate category.Point is, you want shielded wire, but not coaxial cable.Quote from: LinuxHata on July 28, 2024, 07:18:46 amWhile DigiKey is generally not a particularly cheap supplier of wire and cable, $2/m for Raychem is really not bad at all.As for China: well you might try the correct term which I’ve already given you. But a pro tip is to look at the list of wires on DigiKey and note that some of them have a UL style listed — a UL style you can then search for on AliExpress.

author: LinuxHata
author_rank: Frequent Contributor
timestamp: July 30, 2024, 06:19:34 am
content: The main issue is ones listed at DigiKey are not 10A or 15A rated...

author: thm_w
author_rank: Super Contributor
timestamp: July 30, 2024, 09:42:00 pm
content: Quote from: LinuxHata on July 30, 2024, 06:19:34 amAs I said before, what is the AWG or mm2 diameter rating of the wire you have that handles 10-15A? We need a comparison.

author: tooki
author_rank: Super Contributor
timestamp: July 31, 2024, 07:14:07 pm
content: Quote from: LinuxHata on July 30, 2024, 06:19:34 amWell yeah, because that's not how wire and cable is normally sold.Ampacity depends on various factors including ambient temperature, acceptable temperature rise, and acceptable voltage drop over the length you're using. So wire and cable isn't sold with a current rating. That's up to you to determine.