Rant. DC Barrel Jack sizes. - Page 1
Forum section: electronics / general

author: tooki
author_rank: Super Contributor
timestamp: February 09, 2020, 12:46:21 am
content: Sony has adhered to the EIAJ standard since it came out.You can’t blame a company for not adhering to industry standards before those standards were created!Then again I doubt your rant is founded in much of reality anyway...

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 09, 2020, 01:52:49 am
content: Quote from: tooki on February 09, 2020, 12:46:21 amOK.Up next: Rant. USB plugs and cables.

author: David Hess
author_rank: Super Contributor
timestamp: February 09, 2020, 02:55:07 am
content: https://dilbert.com/strip/1994-09-30

author: vk6zgo
author_rank: Super Contributor
timestamp: February 09, 2020, 04:37:09 am
content: I have no idea why laptops use these abominations!Twin pin plugs & sockets have been around forever, & the cable part is usually more "encapsulation friendly" than barrel types.It's not that they use "barrels" because they need the switching function, because they don't use that.The Male part is flimsy, & is always poorly located.This, combined with the mechanical advantage of the barrel, soon dislodges that bit, so, you have to glue the bloody thing in.In the meantime, the cord mounted female connector breaks its strain relief, then, inevitably, the conductors, can't be reconnected, so needs replacement, but no standard size quite fits. ----aaargh!

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 09, 2020, 04:46:38 am
content: To bring in another point of conflict, Dave Jones really dislikes center negative on DC jacks, but his friend Fran Blanche uses center negative on most of her products. What would he say about that? (In her defense, she does include reverse polarity protection and it not working with most of the cheap Ebay special wall warts will lessen a chance a customer tries to use one and complain about the noise.)

author: David Hess
author_rank: Super Contributor
timestamp: February 09, 2020, 04:53:20 am
content: Quote from: NiHaoMike on February 09, 2020, 04:46:38 amCenter negative means the switch is on the positive side which can be advantageous in applications where negative is common.

author: james_s
author_rank: Super Contributor
timestamp: February 09, 2020, 06:41:35 am
content: Quote from: NiHaoMike on February 09, 2020, 04:46:38 amCenter negative is common on music gear, I don't know why but given that it is I can understand the reason one might use it in their own music gear.I do wish someone had the foresight to standardize the sizes based polarity and whether it's AC or DC but it's a bit late for that. Even then you still have all the different voltages.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 09, 2020, 08:25:23 am
content: Don't get me started on this one.

author: tooki
author_rank: Super Contributor
timestamp: February 09, 2020, 08:42:18 pm
content: Quote from: james_s on February 09, 2020, 06:41:35 amThe Japanese did that about 25 years ago:https://en.wikipedia.org/wiki/EIAJ_connector

author: vk6zgo
author_rank: Super Contributor
timestamp: February 10, 2020, 05:54:26 am
content: My old Yaesu FT290R 2.5 watt 2m Ham radio used centre negative.It was, in theory, a battery portable, but many were used at home, operated from a 13.8v DC supply,or mobile, operated from the car DC.(In my case from the "cigarette lighter" socket).In the former case, all was well, but in the latter, if the "barrel" end of the lead was dropped on any exposed metalwork, there was a large "zap" & a blown fuse!

author: Kjelt
author_rank: Super Contributor
timestamp: February 10, 2020, 11:29:33 am
content: Can't we just put a few schotkey diodes in our products so it does not matter what polarity the connector is.BTW I hate those DC barrel jacks, they have no strain relief and there are too many different sizes.

author: tszaboo
author_rank: Super Contributor
timestamp: February 10, 2020, 01:04:12 pm
content: Thats EZ. I dont design products with DC barrel jack, and I loathe DC barrel jack.

author: tooki
author_rank: Super Contributor
timestamp: February 10, 2020, 01:57:20 pm
content: Quote from: Kjelt on February 10, 2020, 11:29:33 amIt makes sense for there to be different sizes, when those sizes encode they voltage, as is the case with the EIAJ system.(I have thought about diodes, too. I first thought about it when I was a kid and first learned about bridge rectifiers. But I hadn’t yet learned about diode drops!)Strain relief is up to the implementation, just like with nearly any connector type.Maybe you guys have had way more trouble with these thing than I have, over the years. I haven’t found them to be especially problematic. (My main objection to them is simply that I wish more products didn’t need them at all, insofar as I’d rather have built-in power supplies with IEC or C8 cords instead of wall warts.)Besides, USB (especially micro-B) has displaced DC barrel jacks in a HUGE percentage of gadgets already, even things not even distantly computer related, and USB-C is enabling that for even more kinds of products. So whining about DC barrel jacks is kinda like whining about how manual typewriters would jam — not untrue, but of dwindling relevance.

author: exe
author_rank: Unknown
timestamp: February 10, 2020, 03:39:04 pm
content: Huh, power socket problems... On my old laptop (asus ux32vd) I had to replace power port every year or more often. They are so unreliable... At the end, the power plug worn out, and I wasn't able to find any good replacement (tried three different types). About a year ago I just soldered the power cable directly, zero issues since then.USB-C looked like an interesting common denominator to all power port problems, but sockets have questionable reliability (talking about macbook pro, both ports on which got worn out in two years). No surprise vendors want to install a temperature sensor in them.

author: tooki
author_rank: Super Contributor
timestamp: February 10, 2020, 06:01:27 pm
content: Quote from: exe on February 10, 2020, 03:39:04 pmWithout in any way intending to be rude or anything, that is most likely down to the user.Some people are simply WAY, WAY rougher on their electronics than others. Like... me, I'm super gentle on mine. My sister is like a bull in a china shop. Literally, we have bought the same product at the same time, more than once, and invariably, hers is broken within a year or two, and mine still looks (and works) brand-new years later. She managed to break off the power plug in her old iBookthree times. (Me, zero, and I owned laptops far longer than she did.) I lost count of how many phone and iPad screens she's cracked. (Me, zero.)And over years of working in IT, the interesting thing I've learned about people who are rough on their gear is thatthey aren't aware they're being rough. They're perpetually baffled at why their stuff is broken!Anyhow, I haven't heard of any widespread issue with USB-C failures in MacBooks*, and they've been using them for years now, so I think it's unlikely that they're particularly delicate.With that said, I still miss the old, original MagSafe 1 connector. It was just perfect. (MagSafe 2, the thinner version of it, pops off far too easily.)*I'm sure such failures do exist, but they're not widespread, and I keep a pretty close eye on the Mac tech world.

author: exe
author_rank: Unknown
timestamp: February 10, 2020, 06:38:51 pm
content: Quote from: tooki on February 10, 2020, 06:01:27 pmWell, searching "macbook pro usb-c falls out" gives 9M results. You decide if it is wide-spread or not.As of my laptops, they are abused a lot, but in my opinion they fail not because of that. I drop them, I squeeze them in a packed knapsack, etc. They keep working. But I'm gentle with ports. The plastic of power ports that I replaced like 5 or 6 times was just very thin and brittle.

author: dnwheeler
author_rank: Regular Contributor
timestamp: February 10, 2020, 06:54:17 pm
content: I don't have any evidence to back it up, but my recollection (from a long time ago) was that center negative was used to ensure the ground contact was made first when plugging in the connector.

author: tooki
author_rank: Super Contributor
timestamp: February 10, 2020, 07:39:40 pm
content: Quote from: exe on February 10, 2020, 06:38:51 pmWhich of course doesn't even begin to mean that there are 9 million pages about the USB-C port failing on a MacBook. After a few pages of hits, it's just random pages that contain one or more of any of those words. (As with any google search for more than one word.)For sure, that's not the rarest problem (it looks like 2017 and later ones retain the plugs better?), it's not as though it's affecting everyone. I'll amend my claim to "...but they're not super widespread", as they do appear to be more common than I thought.

author: tooki
author_rank: Super Contributor
timestamp: February 10, 2020, 07:44:16 pm
content: Quote from: dnwheeler on February 10, 2020, 06:54:17 pmNope, though that might be a side effect in some designs. The reason for center-negative is that then, the outer contact is positive, and the switch in the socket can bridge to the positive of the battery when on battery, or break that and connect to the positive of the AC adapter.

author: Messtechniker
author_rank: Frequent Contributor
timestamp: February 10, 2020, 09:54:04 pm
content: Quote from: Kjelt on February 10, 2020, 11:29:33 amPrecisely!

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 11, 2020, 01:48:46 am
content: Quote from: tooki on February 10, 2020, 07:39:40 pmi think the terms Macbook and Fail is what's triggering all those 9M results.

author: tooki
author_rank: Super Contributor
timestamp: February 11, 2020, 02:41:11 am
content: Nope. “USB” alone is responsible for many... but then again you don’t care about reality, you just wanna rag on Macs like most people who don’t know anything about them.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 11, 2020, 03:29:49 am
content: Quote from: tooki on February 11, 2020, 02:41:11 amYou still love me, despite all my faults.