Thoughts On USB C and the PD Standard Noncompliance

[MrAl]

Hello there,

Recently I had acquired a USB C noncompliant wall wart. It puts out a constant 12vdc to a USB C male connector which plugs into a device. From what I have read now, this is allowed, although may not be the best idea in the world.

I have read people complaining about this kind of practice because they say it can blow out a 5vdc only USB C port. However, does anyone here plug a random USB C adapter into any old device they happen to have and expect it to work?

My thoughts are that there is no way to stop a company from using the USB C connector almost any way they feel like using it, as long as it can survive electrically. The responsibility lies on the end user as to how they decide to use it.

What are your thoughts on this?

 

[rjenkinsgb]

I'd consider it criminal-grade negligence, as it could cause massive damage to devices connected to it.

The USB standards are used internationally & misusing it in a way that could damage other things is just wrong.

Imagine having a wall outlet that takes a 115V plug, and wiring it for 230V, or a 230V one wired to 440V - whoever fitted it would be liable for damage caused & I see no difference with a deliberately misused USB outlet.

 

[For The Popcorn]

USB C PD is a well-established standard and works well to power a multitude of low-voltage DC devices.

The instances of manufacturers using USB C connectors on non-PD higher voltage chargers appears to be exceedingly rare. The best bet is to check the ratings on the power supply. A PD power supply MUST include 5 volts – it will provide 5 volts until/unless a higher voltage is negotiated. It MAY include one or several higher voltages. A purpose-built PD supply may include only one higher voltage, like 20 volts for a laptop supply. A "generic" PD power supply will include more voltage options, up to its power limitation.

Note that 12 volt output is no longer included in the PD standard – PD power supplies may include 12 volts but not all do.

 

[rjenkinsgb]

A PD power supply MUST include 5 volts – it will provide 5 volts until/unless a higher voltage is negotiated.

Exactly!
If, as the OP says, it gives a higher voltage without negotiation, it's an insanely bad design.

 

[MrAl]

Hello again,

Yes, many people do not like the way the USB C is being used by some companies.
The fact remains however, that when you use any wall wart you have to know what it goes to or at least what it can be used for.

When I think all the way back to the late 1970's or so, I remember that some of the wall warts with different voltages used the same size barrel connector. This meant that you MUST know what wall wart goes with what. You can never just grab ANY old wall wart and plug it into a device and expect it to work unless it was made for that device.
In this day and age, with the PD standard, you STILL have to know that, like it or not, and that is because the standard is so variable that it's close to not having any standard at all. I think it is more like a guideline then a standard.
To make this clear, if you buy a device that takes a 60 watt PD adapter and it comes with that you use that adapter. If you want to buy another adapter, you have to buy a 60 watt PD adapter, not a 20 watt PD adapter, and what makes it more difficult is that some PD adapters are rated for 60 watts, but they have three PD USB C outlets, and each one is only 20 watts. That means you buy a 60 watt PD adapter and you still can't use it for your device. You have to find a PD adapter that puts out 60 watts in ONE female USB C port.

So see how this works. Even though the two 60 watt adapters are PD compliant, only one will work with your device. That means you MUST know what wall wart you can use with your device. Since you must know for that scenario, it makes sense that you must know for all scenarios or else your device simply won't work.
If you are stupid enough to plug a 48v wall wart into a device that needs only 5vdc, whose fault can that be.

I realize some of you may not like this idea, I don't like it that much either, but there's no way to stop it. You are going to have to be careful and you have to teach your kids to be careful.
This isn't that uncommon either. We all know that connectors stand alone, and they only take on a specific function when used in some application. The Molex 4 pin connectors on a lot of computers have at least +12 and +5 volts and ground, and most hard drives can plug right in for power. This does not mean that every Molex 4 pin connector can plug into a hard drive and it be certain to power it. We can use 4 pin Molex connectors any way we want.

It is very hard to nail this down to anything more ridged. If a manufacturer decides that the device they make needs 25 volts DC at 1 amp to charge a device, they may decide to use a USB C connector in order to comply with the suggestion that a USB C connector be used for charging all devices in the future. This does not mean that it will be PD compliant, which is a different story.

Think of the last time you plugged your phone in to charge it. Did you grab some unknown wall wart out of a big box and plug it in, or were you well aware of what charger wall wart you were using and what it can do and most important can it work with your phone.

 

[For The Popcorn]

In this day and age, with the PD standard, you STILL have to know that, like it or not, and that is because the standard is so variable that it's close to not having any standard

I think your lack of understanding has blown this way out of proportion. At least, few people would agree with you.

● USB C PD chargers always start at 5 volts and remain there until negotiated otherwise.

● If the PD charger doesn't have the requested voltage available, it will provide the closest lower voltage available. In every case. If the device can work on that voltage, it will. If not, it won't. It will not be damaged by a lower voltage or by plugging into a standard USB charger.

● It's true that some chargers advertise the total power available, even if that power is not available from a single port. When purchasing a charger, you have to look at the specs carefully. If the charger doesn't specify the power available at each port, look elsewhere. The power ratings for all connectors will be shown on the charger itself.

In summary:

● The charger will not provide a higher voltage than requested.

● if the requested voltage is not available, the charger will supply a lower voltage. The device has the option of using that voltage. If it doesn't like it, worst case is it won't charge. No damage to charger or device will occur.

● There is exactly one (or two) kinds of connectors – no problem of having the shell too big or the hole for the pin too small. And no chance of reverse-polarity.

● There's no need to keep a drawer full of chargers, all labeled with sticky masking tape with the fear that of inadvertently selecting the wrong one, ending civilization as we know it. And no need to keep a dozen chargers next to your chair to handle different devices. And no need to move your charger from outlet to outlet as you move around.

● Every device does not need a different charger that will end up in a landfill when that device is retired.

USB C PD is a good thing., and it is becoming a worldwide REQUIRED standard.



Of course, I am one of those rebels who will grab a 12 volt supply that clearly says "use only with this device", cut the connector off and splice on the connector I need. It could be dangerous, but I've still alive for many years after starting the practice when I was 15 or so

 

[rjenkinsgb]

In this day and age, with the PD standard, you STILL have to know that, like it or not, and that is because the standard is so variable that it's close to not having any standard at all.

The critical difference, from what you describe in the first post - is that using the wrong (but compliant) USB-C outlet WILL NOT CAUSE HARM.

What you connect will only slow charge, or not charge at all - but no harm. The highest power & voltage versions are backwards compatible with the lowest demand devices and using a 60W one to charge a phone is OK.

The only variation is the highest-demand device that can be charged. If you don't need to charge a laptop, you can use a cheaper, lower power one for smaller device. The standard is very logical and consistent, to my mind.

Putting 12V on the 5V pins as you described at first, would destroy things!

 

[tumbleweed]

Even though the two 60 watt adapters are PD compliant, only one will work with your device. That means you MUST know what wall wart you can use with your device.

How is that any different than having a wall wart that puts out 5V @ 100mA, but your device needs 500mA?

If you're saying you have a USB C PD charger that always puts out 12V no matter what then your best bet would be to throw it away.

 

[MrAl]

USB C PD is a well-established standard and works well to power a multitude of low-voltage DC devices.

The instances of manufacturers using USB C connectors on non-PD higher voltage chargers appears to be exceedingly rare. The best bet is to check the ratings on the power supply. A PD power supply MUST include 5 volts – it will provide 5 volts until/unless a higher voltage is negotiated. It MAY include one or several higher voltages. A purpose-built PD supply may include only one higher voltage, like 20 volts for a laptop supply. A "generic" PD power supply will include more voltage options, up to its power limitation.

Note that 12 volt output is no longer included in the PD standard – PD power supplies may include 12 volts but not all do.

Hello there,

That's another thing. Why the HELL would an organization responsible for writing and updating the PD standard try to eliminate the 12vdc output setting? That's just completely insane in the membrane. 12vdc is such a common requirement for electronic devices that to eliminate it must mean these people are already far detached from reality.
That means that the jump order would no longer mean going from 9v to 12v to 15v, but from 9v right up to 15v, skipping 12v altogether. WHY THE HELL WOULD THEY DO THAT, or I should say why would they TRY to do that.
Luckily, many manufacturers are smarter than they are and continue to support 12vdc as part of their products that have to supply power under the PD standard.
Even if this 12v elimination strategy was part of the original writing, it's still nuts, but to try to eliminate it LONG after the standard has been around is just plain bat s*** crazy. That means if someone is used a PD charger to start with and needs the 12v output, then the charger breaks down, then they go to buy a new one and it doesnt work with their product anymore because it doesnt put out 12v, they are screwed unless they can find an *older* designed charger that still has the 12v output. See how stupid this is? That tells us something about the mentality of these idiots.

So if you think the manufacturers are wrong, think about who is making the standard also.

We have one fallback, and that is the PDD standard. I think that still covers the 12v output, but an older device may not recognize that newer standard.

 

[MrAl]

How is that any different than having a wall wart that puts out 5V @ 100mA, but your device needs 500mA?

If you're saying you have a USB C PD charger that always puts out 12V no matter what then your best bet would be to throw it away.

Hi,

Oh that's a great idea, then you can go out and buy another adapter for $20 USD (ha ha).

If that's what you want to do, go right ahead, but I won't do that because I'd have to buy new adapters for stuff.
Send me $100 USD I'll do it (ha ha).

Seriously though, if they want to stop companies from doing this, they would have to make a law, and since that law only affects one area of the world, all the world leaders would have to get together and declare war on PD adapters.

 

[MrAl]

The critical difference, from what you describe in the first post - is that using the wrong (but compliant) USB-C outlet WILL NOT CAUSE HARM.

What you connect will only slow charge, or not charge at all - but no harm. The highest power & voltage versions are backwards compatible with the lowest demand devices and using a 60W one to charge a phone is OK.

The only variation is the highest-demand device that can be charged. If you don't need to charge a laptop, you can use a cheaper, lower power one for smaller device. The standard is very logical and consistent, to my mind.

Putting 12V on the 5V pins as you described at first, would destroy things!

Hi,

Yes that is right. So don't do that.

 

[MrAl]

I think your lack of understanding has blown this way out of proportion. At least, few people would agree with you.

● USB C PD chargers always start at 5 volts and remain there until negotiated otherwise.

● If the PD charger doesn't have the requested voltage available, it will provide the closest lower voltage available. In every case. If the device can work on that voltage, it will. If not, it won't. It will not be damaged by a lower voltage or by plugging into a standard USB charger.

● It's true that some chargers advertise the total power available, even if that power is not available from a single port. When purchasing a charger, you have to look at the specs carefully. If the charger doesn't specify the power available at each port, look elsewhere. The power ratings for all connectors will be shown on the charger itself.

View attachment 142488

In summary:

● The charger will not provide a higher voltage than requested.

● if the requested voltage is not available, the charger will supply a lower voltage. The device has the option of using that voltage. If it doesn't like it, worst case is it won't charge. No damage to charger or device will occur.

● There is exactly one (or two) kinds of connectors – no problem of having the shell too big or the hole for the pin too small. And no chance of reverse-polarity.

● There's no need to keep a drawer full of chargers, all labeled with sticky masking tape with the fear that of inadvertently selecting the wrong one, ending civilization as we know it. And no need to keep a dozen chargers next to your chair to handle different devices. And no need to move your charger from outlet to outlet as you move around.

● Every device does not need a different charger that will end up in a landfill when that device is retired.

USB C PD is a good thing., and it is becoming a worldwide REQUIRED standard.



Of course, I am one of those rebels who will grab a 12 volt supply that clearly says "use only with this device", cut the connector off and splice on the connector I need. It could be dangerous, but I've still alive for many years after starting the practice when I was 15 or so

Hello,


Well i can see right off the bat that you never used a PD compliant charger, or at least measured the output of one.
Not all of them put out 5vdc to start, some will put out a lower voltage than that.
Some may put out 5vdc but only with a cable that is not PD compliant. Some that are used with a PD compliant cable will only put out around 1v or around 3.8v but it could be other low voltages too.

To find out what yours actually does, you have to measure it with two types of cables. You then have to measure it with no load and then with a PD compliant load. That's the only way you can tell what the charger can put out, and when it can put it out. Some will put out 12vdc but not any higher.

What this says to me is there is a LOT of variation with these chargers/power sources. It would be incredibly hard to make they all the same, or should I say FORCE them to be all the same.

One thing about us humans: we all want all things to be CONSTANT, but we can't always get that. This is not only with power supplies, it is with almost everything including the weather.

 

[MrAl]

Hello again,

I realize that everybody has their own views on this matter so I don't think everyone will agree on what is best. That's the nature of human beings. Add to that, manufacturers have their own agenda so getting anything the way WE want it is going to be difficult.

 

[rjenkinsgb]

The common standard voltages relate to charging 1, 2, 3 or 4 lithium cells.

12V is too low to charge three cells and excessive to charge two cells; 9V minimises wasted energy for two cell devices.

15V-16V and 19-20V have long been standards for laptop chargers, for machines that use three or four series cells in their batteries.

 

[For The Popcorn]

MrAl calm down. You're sputtering. And much of what you posted is just plain wrong.

As far as using PD? I guess you've missed a number of my posts here. I have discussed here using USB C PD to replace a gaggle of power supplies when traveling. I just completed two nights in a row of operating my CPAP from a 2" cube PD supply. It works flawlessly, replacing a power brick of more than 6× the size and weight.

Since I took the time to understand the standard, this is the arrangement I'm using:

60w PD supply --> 20v trigger --> 10 amp buck converter module --> 12v to CPAP.

Why that arrangement? Because I knew 12 volt operation had been deprecated – I could not depend on PD power supplies supporting it. Going with 20 volts also provides a boost in power available, giving me some margin. Why a 10 amp buck converter, when 3 amps is the maximum available current? I tried a 5 amp rated module, and the inductor quickly became too hot to touch. Now the system is hardly warm to the touch.

 

[MrAl]

The common standard voltages relate to charging 1, 2, 3 or 4 lithium cells.

12V is too low to charge three cells and excessive to charge two cells; 9V minimises wasted energy for two cell devices.

15V-16V and 19-20V have long been standards for laptop chargers, for machines that use three or four series cells in their batteries.

Hi,

Not sure what you are saying here. Are you saying that a power source should be able to put out any voltage except 12v? That would be nuts.

 

[MrAl]

MrAl calm down. You're sputtering. And much of what you posted is just plain wrong.

As far as using PD? I guess you've missed a number of my posts here. I have discussed here using USB C PD to replace a gaggle of power supplies when traveling. I just completed two nights in a row of operating my CPAP from a 2" cube PD supply. It works flawlessly, replacing a power brick of more than 6× the size and weight.

Since I took the time to understand the standard, this is the arrangement I'm using:

60w PD supply --> 20v trigger --> 10 amp buck converter module --> 12v to CPAP.

Why that arrangement? Because I knew 12 volt operation had been deprecated – I could not depend on PD power supplies supporting it. Going with 20 volts also provides a boost in power available, giving me some margin. Why a 10 amp buck converter, when 3 amps is the maximum available current? I tried a 5 amp rated module, and the inductor quickly became too hot to touch. Now the system is hardly warm to the touch.

Hi,

That's great that you got a working solution, I admire that.

You are saying *much* of what I posted is plain wrong, but you don't say what.
Name one thing at a time and we have something to talk about. Please don't create a long list of stuff I won't be able to reply too them all at once. If you do I will only be able to reply to the first one on the list, most likely. Thanks.
This standard is interesting to talk about it does bring out the facts and fallacies.

You might also want to consider that I base most of my facts on actual measurements, not just what I read on the 'web'.

 

[For The Popcorn]

You should consider that my comments come from understanding the standard and actually putting it to use.

 

[For The Popcorn]

Oh that's a great idea, then you can go out and buy another adapter for $20 USD (ha ha).

If that's what you want to do, go right ahead, but I won't do that because I'd have to buy new adapters for stuff.
Send me $100 USD I'll do it (ha ha).

If you plug that power supply into almost any USB C device, chances are extremely high that the magic smoke will be released. Is risking a $400+ phone in a moment of inattention worth the risk?

And why do you need to buy new adapters "for stuff"? Do you have more than one of these non-compliant adapters?

Well i can see right off the bat that you never used a PD compliant charger, or at least measured the output of one.
Not all of them put out 5vdc to start, some will put out a lower voltage than that.
Some may put out 5vdc but only with a cable that is not PD compliant. Some that are used with a PD compliant cable will only put out around 1v or around 3.8v but it could be other low voltages too.

Not if they are PD compliant. Measurement error on your part?

Some will put out 12vdc but not any higher.

The voltages put out depend on the wattage of the charger. 20 volts --> 60 watts. If the charger doesn't put out 60 watts, it will not supply 20 volts.

What this says to me is there is a LOT of variation with these chargers/power sources.

Indeed there is, depending on the rated wattage. It's really not that difficult to understand.

It would be incredibly hard to make they all the same, or should I say FORCE them to be all the same.

It's a standard. To say a power supply is PD compliant, it must meet the standard.

Your RANT about 12 volt operation was already addressed by rjenkinsgb.

 

[For The Popcorn]

Name one thing at a time and we have something to talk about. Please don't create a long list of stuff I won't be able to reply too them all at once.

That's a good start. I typed as slowly as possible – I hope you'll be able to read it.