Thoughts On USB C and the PD Standard Noncompliance

[Nigel Goodwin]

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.

It's supposed to be a 'charger', rather than a PSU, and as already explained 12V isn't a particularly useful voltage for a charger.

 

[MrAl]

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?




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


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.


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




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.

Hello again,

I can see there are differences of opinions here and you are unable to do the simplest thing I asked of you.

My main point is that the USB C connector is JUST a connector. It's not a standard in and of itself.
I have answered most of your questions already, and with attention to "one minute of inattention", I NEVER have one minute of inattention when it comes to a $400 USD device. Maybe you do but that's your problem not mine.


I'll repeat the main point two more times and if you don't like it that's not my problem.
[1] The USB C connector is just a connector it is not a standard in and of itself.
It is nice that some units will not blow out another unit, but that only happens if you plug the wrong unit into the wrong unit. If you don't know what the units are capable of, you shouldn't plug anything in.

[2] The USB C connector is just a connector it is not a standard in and of itself.

In closing, all I can say is that you have expressed your opinion and that has been duly noted. That's kind of what i was looking for with this thread.

 

[MrAl]

It's supposed to be a 'charger', rather than a PSU, and as already explained 12V isn't a particularly useful voltage for a charger.

Hi,

So are you saying that if a device is not a 'charger' then it is automatically not PD compliant?

 

[Nigel Goodwin]

Hi,

So are you saying that if a device is not a 'charger' then it is automatically not PD compliant?

I'm saying that it's main use, and design purpose, is as a charger - where 12V is a poor choice.

I've no interest in reading the PD spec. to see what might, or might not, be PD compliant.

But from what has been said here, 12V output would presumably mean it fails PD compliance?.

 

[MrAl]

Hello again,

I am starting to see another facet of this 'standard'.
There is the theoretical standard, and the standard as being interpreted by manufacturers.
I can see some have talked about very severe restrictions that manufacturers do not adhere to.
For example, there are adapters that can only put out up to 12vdc, that means 5v, 9v, 12v, so would we have to think about those as being just partially compliant.
Another example, manufacturers are putting out adapters that can still do 12vdc. Are they non compliant too.

We also have to remember that there are different standards for a PD compliant device, not JUST one. That means that an adapter that is compliant to PD2.0 may not be compliant with PD3.0, and so the specs can be different.

 

[MrAl]

I'm saying that it's main use, and design purpose, is as a charger - where 12V is a poor choice.

I've no interest in reading the PD spec. to see what might, or might not, be PD compliant.

But from what has been said here, 12V output would presumably mean it fails PD compliance?.

Well you got me wondering if it might be still PD2.0 compliant.

Yeah there is a lot to it, maybe it's just too complicated to talk about on a message board.

 

[For The Popcorn]

Sigh. This should be moved to the rants section.

A USB C connector is just a connector. A USB C PD power supply is that because it complies to the USB C PD standard.

 

[For The Popcorn]

This is a North American NEMA 120V AC 3-conductor plug. Used properly, it is safe and effective.

This is a pair of North American NEMA 120V AC 3-conductor plugs. Each of these plugs conform to a NEMA standard.

Does that mean that the cable is safe and complies with NEMA standards? The answer is a resounding NO. In the same way putting a USB C connector on a piece of wire doesn't make it USB C PD compliant.


This table may help you understand why every USB C PD changer doesn't have every voltage. Say you have a 15 watt charger. It only has 5 volts available. Why? Because supplying 15 watts only requires 5 volts. Why would "they" add voltages that aren't needed to deliver the rated wattage?

A 45 watt charger will deliver 5v, 9v, 15v and possibly 12v. Why? Because 15 volts at the maximum permitted current is needed to supply 45 watts.

A multi-port charger follows the same scheme, based on the ratings of each port. This is where it gets a bit tricky – a 60 watt charger with 4 ports shares 60 watts across the 4 ports. It may or may not be able to supply the full 60 watts to a single port. If it cannot, it will not have a 20v output available. I don't consider this a defect or desception, as ii fits a typical use case.

 

[MrAl]

This is a North American NEMA 120V AC 3-conductor plug. Used properly, it is safe and effective.

Hello,

Sorry to say, but I see some of your statements are logically inconsistent.
"Used properly"
That's what I have been saying all along that you said was a bad way to reason with the USB C connector and the PD standard, or just the USB C connector alone.

If you use the adapter with a USB C connector "properly", you have no problems. It doesn't matter if it puts out 5v, 9v, 12v, 15v, 20v, 36v, or 48v (which BTW is the newest standard from what I had read although there may be a few more voltages than I listed there). It doesn't even matter if it puts out 1012 volts, (one thousand, twelve volts). If you don't know how to "use it properly" (your own words paraphrased) you could damage your equipment.
This is a little interesting in its own right. If it could put out 1000 volts, I bet more people would be damn sure it was being used correctly, or at least I would hope so.

So now you are arguing that my opinion was the right way to look at it, that the responsibility lies on the user for the most part.

I also see you are a judgmental poster:
"

Sigh. This should be moved to the rants section.​

"

That's not such a good idea. If you don't like what someone has to say, you do not have to participate in any thread, but you shouldn't try and make judgements for all members both today and in the years to come. It's not even good for you yourself. If any of us take anything from this thread, it should at least be:
"Watch out what you plug your devices into or what you plug into your devices, because manufacturers have their own idea about what a good design is and that design may not be compatible with your device, and can even cause damage."

 

[rjenkinsgb]

So now you are arguing that my opinion was the right way to look at it, that the responsibility lies on the user for the most part.

Absolutely not!

A USB C PD port will only output anything other than 5V if the connected device requests that, and it can support the requested voltage.

USB PD is part of the USB 3.1 & 3.2 standards, and the cross-connection between the USB standards and USB-C connectors is integral to those standards.

A fragment from the standards docs:

3 LPM Physical Layer
3.1 Physical Layer Overview
The Physical Layer (PHY Layer) defines the signaling technology for USB Type-C Connector Software Interface. This chapter defines electrical requirements and parameters of the UCSI PHY Layer required for interoperability between UCSI components and LPM.
3.2 Physical Layer Description
USB Type-C Connector Software Interface supports Half-duplex, Synchronous Communication.
3.3 Transmit order of various sizes of data
This section describes the order of bits on the wire that shall be used when transmitting data of varying sizes. The possible data sizes are Byte, Word, DWord, and it shall be transmitted in the little-endian format .... .... ....

 

[For The Popcorn]

It's ok MrAl – you can go ahead and RANT to your heart's content. I'll continue bending USB C PD power supplies to my will, without a trace of smoke.

 

[tumbleweed]

"Watch out what you plug your devices into or what you plug into your devices, because manufacturers have their own idea about what a good design is and that design may not be compatible with your device, and can even cause damage."

I'll say this again... if your "thing" requires that note then it's not compliant and you should ask for a refund, paint it bright red with a skull and crossbones on it, or throw it away,

 

[For The Popcorn]

^^^^^ I only clicked LIKE because LOVE isn't an option! ^^^^^^

 

[MrAl]

I'll say this again... if your "thing" requires that note then it's not compliant and you should ask for a refund, paint it bright red with a skull and crossbones on it, or throw it away,

Hello there,

Well see, you are trying to force the USB C connector to bend to your standards.
You can try to do that if you like, but what you say may or may not be possible. For example, how will you know you got a non-compliant PD adapter???

 

[For The Popcorn]

The first clue is that it's not marked as PD compliant. The second clue is that it's not marked with the available voltages.

USB C PD is in use by millions of people every day, and next year its use will be required in the EU.

I think you're preaching to a choir of one. Nobody appears to be rallying to your support.

 

[rjenkinsgb]

I don't know about US "UL" standards, but in the UK / EU, mis-using any kind or recognised standards marking or mis-describing a product is illegal.

Also, the strict consumer laws against non-compliant or poor quality goods put the entire responsibility on the seller, so no UK / EU business would ever knowingly sell anything that could result in them having to compensate buyers for damage, or be sued!

If you buy direct from overseas, that's your responsibility.

 

[MrAl]

The first clue is that it's not marked as PD compliant. The second clue is that it's not marked with the available voltages.

USB C PD is in use by millions of people every day, and next year its use will be required in the EU.

I think you're preaching to a choir of one. Nobody appears to be rallying to your support.

Hi,

What if it is marked PD 3.0, 5v, 9v, 12v, 15v.
Then you find out it is not PD compliant when you plug it in and something blows out.
This brings in the question of what a good way would be to test these devices.

You seem to have to try to include other people in your arguments you can't seem to stand on your own.
"Rallying", I guess you need that, i DO NOT. Besides that, you don't know who is going to read these threads next week.
This means your statement about "rallying" means nothing anyway.
I would suggest you stop trying to draw 'ghosts' into the discussion when all the people are not hear yet. Even then i would not recommend it though.

It seems talking to you is like talking to a tape recorder on 'play'. I don't think I will be able to reply to any more of your discussion here. Perhaps in another topic in another thread. You can have the last word if you feel it is necessary, but your opinion has been made clear already, as was mine.

 

[MrAl]

I don't know about US "UL" standards, but in the UK / EU, mis-using any kind or recognised standards marking or mis-describing a product is illegal.

Also, the strict consumer laws against non-compliant or poor quality goods put the entire responsibility on the seller, so no UK / EU business would ever knowingly sell anything that could result in them having to compensate buyers for damage, or be sued!

If you buy direct from overseas, that's your responsibility.

Hi,

Yes but you won't know it until you plug it in.
This brings up the question of what a good way would be to test these PD devices without plugging them into our devices.

 

[For The Popcorn]

This brings up the question of what a good way would be to test these PD devices without plugging them into our devices.

I was a skeptic the first time I tried a PD charger. Until I played around with it and figured out the output possibilities. It performed exactly as it was expected to do, and nothing was harmed in the process.

Testing a PD power supply would be simple. Get a PD trigger with selectable voltage selection as shown in the picture and hook up a volt meter to the output.

Extending this a bit further, you could add an in-line USB volt/power meter and an adjustable load to characterize voltage vs load.

I suggest a PD trigger similar to this one. Some types that are scarely bigger than the USB C connector use solder jumpers to set the voltage. A microscope and steady hand is required to make changes on those.

If you feel the need to tell me this test wouldn't be legitimate, please refrain from doing so.

 

[rjenkinsgb]

Yes but you won't know it until you plug it in.

?? I would!

If it's sold by a reputable UK seller, it will work as stated.