How is this INSANITY safe?! - Page 1
Forum section: electronics / general

author: Benta
author_rank: Super Contributor
timestamp: October 22, 2021, 09:56:58 pm
content: What's your problem? And why is it INSANITY?

author: Kjelt
author_rank: Super Contributor
timestamp: October 22, 2021, 10:10:53 pm
content: I also think it is stupid to increase the voltage to 48V which can cause arcing by disconnecting, warn that new special cables are needed to comply but then keep the same connector.Thus any old not compliant existing cable will work but is unsafe. Stupid!Create a new hot plug safe connector and system.

author: eti
author_rank: Super Contributor
timestamp: October 22, 2021, 10:17:43 pm
content: Quote from: Kjelt on October 22, 2021, 10:10:53 pmThe entirety of USB-C is a mess, not to mention something I've said a few times, that the connector design and quality is a joke. Folded tin (or w/e it is) as opposed to looking at the SOLID mechanical, LATCHING design of the Apple "lightning" port (for the pedants, in this sentence I am ONLY referring to the SOLID steel plug, the detents in the sides of which afford a secure, unabiguous "CLICK!" when it latches into the socket, where there are matching, sprung, domed(?) fingers which sit snugly in aforementioned detents, thus affording a secure retention method - not to mention the SOLID housing, and the tight, but not too tight tolerances between the plug and the equally well designed, SOLID socket housing.USB-C is horrible, and I've not even covered the electrical aspects in this post.

author: james_s
author_rank: Super Contributor
timestamp: October 22, 2021, 10:23:38 pm
content: It's 48V, not hundreds of volts. PoE uses 48V, ok not delivering hundreds of watts but the power is still significant, and that isn't burning down buildings left and right.

author: eti
author_rank: Super Contributor
timestamp: October 22, 2021, 10:26:12 pm
content: Quote from: james_s on October 22, 2021, 10:23:38 pmYep, hundreds of watts, and this hasn't been released yet - I don't see it going well ("you cannot change the laws of physics, Cap'n", as Scotty said)

author: thm_w
author_rank: Super Contributor
timestamp: October 22, 2021, 10:31:04 pm
content: Quote from: james_s on October 22, 2021, 10:23:38 pmHi-POE does 100W at 52V apparently, and it goes over much longer distances:https://www.perle.com/supportfiles/poe_background_technical_note.shtml

author: eti
author_rank: Super Contributor
timestamp: October 22, 2021, 10:33:23 pm
content: Quote from: thm_w on October 22, 2021, 10:31:04 pmOne would think that PoE, being an industrial standard, would have been designed to a higher level of quality than this consumer junk - I am unsure - any idea?

author: ejeffrey
author_rank: Super Contributor
timestamp: October 22, 2021, 10:45:07 pm
content: Quote from: Kjelt on October 22, 2021, 10:10:53 pmUSB-C cables have electronic tags that identify their capabilities unless it is a base USB 2.0 only cable limited to 3A charging. I expect they will continue that here requiring the cable to specifically indicate that it is 48V tolerant. It leads to confusion but not safety problems. Non compliant devices might advertise more than they can handle but that would be true regardless.Most 20V systems arc as well on connection and disconnection. I haven't seen that with USB C. Perhaps the active shut off is fast enough to prevent a visible arc? I'm not sure what the standard says about this.Also, while PoE doesn't deliver 240 watt in a single cable it can supply far beyond that in a bundle of cables that are run for long distances and through raceways and conduit. USB cables are short and not run in large bundles.USB C has problems but the hand wringing here is pretty silly.

author: eti
author_rank: Super Contributor
timestamp: October 22, 2021, 10:50:13 pm
content: Sleep-walking into mass acceptance of a style of delivery system which has been proven MANY TIMES to be flawed, confusing and dangerous, is not "hand wringing"As you wish. Follow the lemmings ---->

author: ataradov
author_rank: Super Contributor
timestamp: October 22, 2021, 10:51:13 pm
content: Quote from: eti on October 22, 2021, 10:33:23 pmWhat makes you think so? And what is "an industrial standard"? And why do you think it is "junk"?You seem to not like thing just for the sake of not liking things without any actual evidence.

author: ataradov
author_rank: Super Contributor
timestamp: October 22, 2021, 10:51:50 pm
content: Quote from: eti on October 22, 2021, 10:50:13 pmLinks to the proofs?

author: james_s
author_rank: Super Contributor
timestamp: October 22, 2021, 10:52:54 pm
content: I was not aware of PoE being "industrial". The first time I ever saw it was in a plain old ordinary office, it was used to power the desk phones we had there. Now I use PoE right at home in my house to power my security IP cameras, they are consumer electronics.I'm not a fan of USB-C for a number of reasons, but I see no evidence of it being unsafe.

author: Benta
author_rank: Super Contributor
timestamp: October 22, 2021, 10:53:43 pm
content: The USB-C is actually well thought out IMO.The higher power is only available after negotiation (as with all USB interfaces), and heck, 5 A is 5 A, this has been working for several years.The only new thing is the higher negotiable voltage, and the "horror story" about sparks flying all over the place because it's 48 V instead of 20 V just doesn't hold water. The plug has different length pins to avoid even the possibility of that.Somehow that Linus whatever guy wasn't first in line when the Good Lord distributed brains.If you want bedside reading: here you go:https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%20R2.0%20-%20August%202019.pdfNow take a deep breath and carry on.

author: ejeffrey
author_rank: Super Contributor
timestamp: October 22, 2021, 11:02:08 pm
content: To answer my own question after 2 min of searching :https://www.anandtech.com/show/16712/usbc-power-delivery-hits-240w-with-extended-power-rangeYes, cables supporting "extended power range (EPR)" will identify themselves via the electronic tag and also have additional mechanical requirements to prevent arcing and short circuits as well as shorter CC pins so that the power supply can shut down power during disconnect before the VBUS disconnects.I doubt it is perfect, and there will likely be problem with cheap non-compliant devices on the market, but I can't see how this is fundamentally flawed, especially given that the 100W version has been working fine for years with these same "problems." Going from 20 to 48 V just doesn't provide significant additional hazard and the current isn't increasing (still 5A max). Arcing is a potential problem, but it's not really a safety issue. It's more about the hardware destroying itself.

author: Benta
author_rank: Super Contributor
timestamp: October 22, 2021, 11:04:30 pm
content: Quote from: eti on October 22, 2021, 10:50:13 pmI've used USB for years and years and never found it to be "flawed". In fact, it's been the only HW interface that I could use without even turning on my brain. Always.Automatic recognition, driver install if needed, etc., etc., etc. no matter which kind of device.Ethernet and WLAN was much more effort.But perhaps you have an own UKSB standard in mind which will rule the world in the future?

author: Kjelt
author_rank: Super Contributor
timestamp: October 23, 2021, 07:40:14 am
content: Quote from: ejeffrey on October 22, 2021, 11:02:08 pmThen I withdraw my earlier comment. As long as they have this kind of authentication of the cable before going full power.In the case of PoE my previous company had some issues with long 40-60m cables when after the installation in the building it came out that the installer had used Clad type of utp cable instead of the prescribed full Cu cable. Also the AWG (wire diameter) should be taken into consideration for higher power devices on longer runs of cable.The installer initially saved $7000 on the cable but went $50000 in the minus when he had to replace all the cables with the correct ones, mainly on manhours for the double work.

author: Halcyon
author_rank: Unknown
timestamp: October 23, 2021, 11:19:57 am
content: Quote from: eti on October 22, 2021, 10:17:43 pmI've actually had more Apple lightning cables physically fail (snap) than USB-C. I'm not a fan of the Dell USB-C docks, but even they seem to hold up to normal consumer use. Even through normal use, I'm finding myself having to replace Apple lighting cables far more often.

author: BradC
author_rank: Super Contributor
timestamp: October 23, 2021, 12:38:30 pm
content: Quote from: Halcyon on October 23, 2021, 11:19:57 amWhat are you doing to them? I've had destructive toddlers abuse iDevices and lighting cables for years and never broken one, and they've tried hard!My wife has bent the USB-C connector on her Macbook charging cable but it still works at this point.

author: MadScientist
author_rank: Frequent Contributor
timestamp: October 23, 2021, 12:42:54 pm
content: I would agree , lightening is a terribly fragile cable arrangement . We end up buying 4-6 a year both Apple and unbranded. Both fail typically the fingers deteriorate , the cable fraud at the Apple end , the plug pulls out of the plastic casingAt least usb is cheap

author: james_s
author_rank: Super Contributor
timestamp: October 23, 2021, 06:30:22 pm
content: The only time I've ever encountered a bad lightning cable was one my dad had on his boat and the contacts corroded. Marine air is very hard on anything metal though so I'm not sure I can really fault a cable not specifically designed for it for failing.The USB-C charging cable on my Macbook doesn't stay in very well anymore, just the weight of the cable draped off the edge of the table or sofa is enough to work it loose. I get about a year out of a cable before it starts to get flaky, I've broken a couple of them from the stupidly slick and shiny bottom of the laptop sliding off the back of the sofa where I set it to get up.

author: Halcyon
author_rank: Unknown
timestamp: October 24, 2021, 12:36:06 am
content: Quote from: BradC on October 23, 2021, 12:38:30 pmNothing too out of the ordinary. With Apple cables, usually the first thing to go is the actual strain relief or the outer plastic starts to split, but it's easy to accidentally bend the actual lightning connector from the main plug housing. They are relatively brittle so even a small bend and the connector will easily break clean off.I've also had quite a few dead data ports in iDevices themselves, I don't know the cause. Sometimes they just fill up with lint and crud from normal use, but other times even after a good clean, the data pins just stop working.

author: Bassman59
author_rank: Super Contributor
timestamp: October 24, 2021, 06:24:02 pm
content: Quote from: Halcyon on October 24, 2021, 12:36:06 amEveryone had problems with strain relief failures on Lightning cables early on (I have a bunch with heat shrink around the end), but honestly, in the last several years that problem seems to have been fixed. I haven't had a bad Apple-branded Lightning cable in quite a while -- and this is with a kid who yanks the cable out of his iPad. All three of our cars have Lightning cables attached to the charge/data ports and they get plugged and unplugged multiple times a day (well, one car sits mostly). (Off-brand cables, except for the Ikea cables which are great, have been long since cycled out of use and binned.) I think that cable failure as described is a solved problem and you're just repeating ancient anecdotes that no longer apply.QuoteCleaning the lint out ports is fairly common. A good thin dental pick helps!(Anecdote alert) I've never had the connectors themselves fail; every charging problem got traced to worn-out cable. As others have noted, the gold fingers (insert wah-wah trumpet sound!) on the device end of the connectors can get scraped off. Again, though, this is still common with cheap knock-off cables, not with the Apple cables.Also in anecdote land: my friends with Android phones are always complaining that the micro-USB ports on the phones fail easily. And they do, because it's a shitty connector.

author: ogden
author_rank: Super Contributor
timestamp: October 24, 2021, 06:42:20 pm
content: Quote from: eti on October 22, 2021, 10:33:23 pmIt is fallacy to think that industrial means "better". Often it's opposite because industrial devices are tailored for professionals while consumer stuff - for anybody (to say it politely).

author: Halcyon
author_rank: Unknown
timestamp: October 25, 2021, 03:10:29 am
content: Quote from: Bassman59 on October 24, 2021, 06:24:02 pmI'd make the counter-argument that your thoughts and opinion are just as valid as mine. To then state that my opinion no longer applies either suggests you believe your opinion is somehow more valid than mine, or you believe that my recent real-world experiences are somehow fabricated or exaggerated. Which is it?QuoteYep, but anecdotal evidence is still very valid. I personally "deal with" on average 2 iDevices per week and dead ports (where they need to be replaced before I can work on them) aren't common, but aren't unheard of either. I probably replace maybe 5 ports per year?As for Micro USB yes, they sucked! But quit living in the past, most manufacturers like Samsung haven't used Micro USB on their devices since 2018. Hardly a relevant problem these days since most phones are using USB-C which is a much more robust connector. Of course some budget phones still use Micro USB, but when the overall cost and quality of the handset is not important. what do you expect?To use your own argument back at you: that failure is "a solved problem and you're just repeating ancient anecdotes that no longer apply".On the subject of anecdotal evidence, recency is very important.

author: Bassman59
author_rank: Super Contributor
timestamp: October 25, 2021, 06:44:58 pm
content: Quote from: Halcyon on October 25, 2021, 03:10:29 amUh, that's what I said.

author: Halcyon
author_rank: Unknown
timestamp: October 25, 2021, 06:53:26 pm
content: Quote from: Bassman59 on October 25, 2021, 06:44:58 pmYes, so to reiterate my point, just because your experiences with failing Apple lighting cables haven't been recent, doesn't mean that everyone else's haven't either. The majority of mine have been over the past few years. I can't say for certain whether their cables are getting better or worse (or remaining the same), but in my recent experience, USB tends to be significantly more robust than Lightning and I've used a hell of a lot more USB cables over the years.

author: Just_another_Dave
author_rank: Regular Contributor
timestamp: October 25, 2021, 08:39:12 pm
content: Quote from: Kjelt on October 22, 2021, 10:10:53 pmBelow 50V there’s no risk of permanent damage to the user, so it should be completely safe. Additionally, the converters used in those devices usually have short circuit protectionsRegarding the cable, usb-c just increases to those voltages if an adequate cable is used

author: thm_w
author_rank: Super Contributor
timestamp: October 25, 2021, 09:49:14 pm
content: Quote from: Just_another_Dave on October 25, 2021, 08:39:12 pmYou can die from a 9V battery, so not completely safe, but most likely near enough as the voltage is not easily accessible. As mentioned above it should be negotiated then disabled as soon as a cable is unplugged.and yeah if they didn't have smart short circuit protection/temperature monitoring, could possibly start a fire with an old frayed cable. "The temperature sensor shall be co-located with the repeater for accurate thermal reporting." I assume that would be able to monitor for a bad connection.

author: Benta
author_rank: Super Contributor
timestamp: October 25, 2021, 10:01:25 pm
content: Quote from: thm_w on October 25, 2021, 09:49:14 pmReally? Do present an example, please (i'm not talking about swallowing or inhaling one).The only place where you'll feel a 9 V battery is on your tongue, and that's how I've tested them for the last 40+ years when a 'meter wasn't available.

author: thm_w
author_rank: Super Contributor
timestamp: October 25, 2021, 10:13:56 pm
content: Quote from: Benta on October 25, 2021, 10:01:25 pmLooks like I was wrong about there being a documented case with a 9V battery. But theoretically it is possible if you break far past the skin and have a good enough connection through your heart or brain. Tongue would not be a problem, as its just going through the muscle there.Some <40V cases here: sci-hub.mksa.top/10.1016/0379-0738(95)01804-2

author: Benta
author_rank: Super Contributor
timestamp: October 25, 2021, 11:15:26 pm
content: Quote from: thm_w on October 25, 2021, 10:13:56 pmAre you pulling my leg?A Chinese study on seven welders that were electrocuted using Chinese electric welders is your reference? Wow.And yes, breaking "far past the skin" is indeed a danger... like an ice pick in your brain. But the electricity part is then somewhat out of the picture.

author: thm_w
author_rank: Super Contributor
timestamp: October 25, 2021, 11:57:13 pm
content: Quote from: Benta on October 25, 2021, 11:15:26 pmNot necessarily out of the picture in all cases as some medical products are intended to make good contact with skin, or pierce the skin (eg ECG, TDCS, EMG). If you've ever had a ECG, they may literally sand through the top layers of your skin to get a good electrical contact.sci-hub.mksa.top/10.1109/tia.2009.2036541QuoteSo it looks like up to 24V is "really safe" in even extreme conditions, eg. high humidity etc.

author: fourfathom
author_rank: Super Contributor
timestamp: October 26, 2021, 01:56:59 am
content: Remember land-line telephones? Those use flimsy RJ-11 connectors and carry current-limited 48V, plus a superimposed 90VAC when ringing.

author: james_s
author_rank: Super Contributor
timestamp: October 26, 2021, 02:28:00 am
content: I remember getting zapped by one when I was a kid, I was messing with the connector just as someone happened to call.

author: Bud
author_rank: Super Contributor
timestamp: October 26, 2021, 05:51:46 am
content: Quote from: Benta on October 25, 2021, 10:01:25 pmConnecting to and disconnecting a battery from a highly inductive load like a primary of a mains transformer will produce high voltage across the inductor terminals at the moment the battery is disconnected. Under "favourable" conditions that may potentially result in dear consequences from high voltage shock.As a kid and a beginner in electronics years ago i was told not to touch transformer's terminals when doing transformer windings conductivity testing using a meter. That did not sink until i was shocked one day because of doing exactly that.

author: Kjelt
author_rank: Super Contributor
timestamp: October 26, 2021, 07:45:33 am
content: Quote from: Just_another_Dave on October 25, 2021, 08:39:12 pmNo, below 50VDC the risk of death by electrocution is almost zero but that does not mean it is safe, you can still get burn wounds by arcs and/or neurological effects from a shock.Safe means, absolutely nothing can happen. In case of electricity this can never be assumed, as you learn in college or or any electricity safety course like NEN3140 or equal.QuoteI hope they are UL certified and idiot proof before put in consumers homes.In the industry anything above 100VA is labeled "potential fire hazzard", check for instance NEC class 2 compliancy.Everything above 100VA should be UL certified.

author: antenna
author_rank: Frequent Contributor
timestamp: October 26, 2021, 08:14:26 am
content: What I would love to see is a symmetrical, magnetically attached charger. We already have a solid-state solution to disconnect the 48v to prevent arcing. Think about it. Our phones already light up when we so much as look at them, and we all pick up our phones before yanking the cable, so why not tell the phone to interrupt the charge cycle for the first 10 seconds of gyroscopic change and teach the users to either yank it within 10 seconds of disturbing the device or leave it connected until it is set it down again. The charger would not function unless in the presence of the phone (eliminating the shock risk) via a continuity or other voltage/sense circuit. I, for one, would be just fine using a standard USB-C cable for the few times I need to hard-wire data to or from my device. With wifi capability, data transferred via USB cable is almost a thing of the past so to heck with trying to pair the two functions into one cable. How much debugging, cable data transferring or tethering do you do? Two gold-plated AC contacts for power and a magnet in the middle to hold it there and put that useless data port somewhere else. Done.

author: dl6lr
author_rank: Frequent Contributor
timestamp: October 26, 2021, 08:59:32 am
content: Quote from: Bassman59 on October 24, 2021, 06:24:02 pmNever had one failing (apart from the one where the whole socket was ripped off the board by some gorilla). The only thing is the plugs have some wear and so the cables are replaced periodically. That is one of the design features (Mini-USB was worse, as the socket inside the device wears out).

author: Just_another_Dave
author_rank: Regular Contributor
timestamp: October 26, 2021, 09:52:01 am
content: Quote from: Kjelt on October 26, 2021, 07:45:33 amGetting burned is not a permanent damage (it will end up healing). Obviously, the damage caused by joule effect on your organs is also a matter of exposure time, but below 50V there is enough time to deactivate the device causing electrocution even manually (with the typical big red button available in most labs for that purpose). Above that voltage automatic protections are mandatoryRegarding neurological effects, I understand that usbc is not meant to be plugged in someone’s head, but I wouldn’t be surprised if someone gets shocked in his tongue

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: October 26, 2021, 09:54:32 am
content: I realise I might be singing Hail Satan! to the choir here, but...Phones simply use too much power.Whilst I recognise the strides in power consumption in Arm systems vs Intel, the apps for phones are obnoxious in terms of CPU/power usage. And the browser vendors are culpable for allowing the mobile version of websites to be presented so shittily.edit: spelling

author: Ranayna
author_rank: Super Contributor
timestamp: October 26, 2021, 02:48:06 pm
content: I think the arcing risk is not so much problematic for health reasons.But it may quickly damage the cables or connectors.For 90 Watt Power over Ethernet, which also uses 48 Volts, this already is an issue. You are supposed to disable power before unplugging the RJ45 jack. Unplugging while full power is applied will ark and damage the connectors.Also it is just a matter of time for these cables to be faked. They will claim to support this 240 watt charging, the chip will claim to support this, but the one strand "copper" wire will vaporize