Author Topic: How is this INSANITY safe?!  (Read 6879 times)

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Offline Bassman59

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Re: How is this INSANITY safe?!
« Reply #25 on: October 25, 2021, 06:44:58 pm »
On the subject of anecdotal evidence, recency is very important.

Uh, that's what I said.
 

Offline Halcyon

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Re: How is this INSANITY safe?!
« Reply #26 on: October 25, 2021, 06:53:26 pm »
On the subject of anecdotal evidence, recency is very important.

Uh, that's what I said.

Yes, 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.
 

Offline Just_another_Dave

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Re: How is this INSANITY safe?!
« Reply #27 on: October 25, 2021, 08:39:12 pm »
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.

Below 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 protections

Regarding the cable, usb-c just increases to those voltages if an adequate cable is used
 

Offline thm_w

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Re: How is this INSANITY safe?!
« Reply #28 on: October 25, 2021, 09:49:14 pm »
Below 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 protections

Regarding the cable, usb-c just increases to those voltages if an adequate cable is used

You 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.
 

Offline Benta

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Re: How is this INSANITY safe?!
« Reply #29 on: October 25, 2021, 10:01:25 pm »
You can die from a 9V battery

Really? 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.

 

Offline thm_w

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Re: How is this INSANITY safe?!
« Reply #30 on: October 25, 2021, 10:13:56 pm »
Really? 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.

Looks 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
 

Offline Benta

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Re: How is this INSANITY safe?!
« Reply #31 on: October 25, 2021, 11:15:26 pm »
Looks 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

Are 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.

« Last Edit: October 25, 2021, 11:18:50 pm by Benta »
 

Offline thm_w

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Re: How is this INSANITY safe?!
« Reply #32 on: October 25, 2021, 11:57:13 pm »
Are 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.

Not 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.2009.2036541

Quote
Given that four of the five scenarios presented in Table V show that a person with sweaty skin making medium body contact between 36 and 49 V could suffer ventricular fibrillation

So it looks like up to 24V is "really safe" in even extreme conditions, eg. high humidity etc.
 

Offline fourfathom

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Re: How is this INSANITY safe?!
« Reply #33 on: October 26, 2021, 01:56:59 am »
Remember land-line telephones?  Those use flimsy RJ-11 connectors and carry current-limited 48V, plus a superimposed 90VAC when ringing.
 

Offline james_s

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Re: How is this INSANITY safe?!
« Reply #34 on: October 26, 2021, 02:28:00 am »
I remember getting zapped by one when I was a kid, I was messing with the connector just as someone happened to call.
 

Offline Bud

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Re: How is this INSANITY safe?!
« Reply #35 on: October 26, 2021, 05:51:46 am »
You can die from a 9V battery

Really? 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.

Connecting 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.
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Offline Kjelt

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Re: How is this INSANITY safe?!
« Reply #36 on: October 26, 2021, 07:45:33 am »
Below 50V there’s no risk of permanent damage to the user, so it should be completely safe.
No, 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.

Quote
Additionally, the converters used in those devices usually have short circuit protections 
I 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.
 

Offline antenna

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Re: How is this INSANITY safe?!
« Reply #37 on: October 26, 2021, 08:14:26 am »
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.
 

Offline dl6lr

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Re: How is this INSANITY safe?!
« Reply #38 on: October 26, 2021, 08:59:32 am »
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.

Never 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).
 

Offline Just_another_Dave

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Re: How is this INSANITY safe?!
« Reply #39 on: October 26, 2021, 09:52:01 am »
Below 50V there’s no risk of permanent damage to the user, so it should be completely safe.
No, 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.

Quote
Additionally, the converters used in those devices usually have short circuit protections 
I 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.

Getting 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 mandatory

Regarding 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
 

Offline Ed.Kloonk

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Re: How is this INSANITY safe?!
« Reply #40 on: October 26, 2021, 09:54:32 am »
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
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Online Ranayna

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Re: How is this INSANITY safe?!
« Reply #41 on: October 26, 2021, 02:48:06 pm »
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  :-BROKE
 
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