General > General Technical Chat

The EU is enforcing USB-C on portable devices

<< < (37/111) > >>

tooki:
I hear you. It is maddening how the results can be totally different depending on where you are, what browser or OS you use, or trivial differences in wording.

Monkeh:
So, I see it requires special cables (not that USB-C is any different, really, to cover the different power classes) and, worse, sockets with switches.

Indeed, it seems USB-PD is for practical matters USB-C only, whether that be C-to-C or fixed on the supply side. I suppose this is why the likes of Qualcomm QC took off initially.

Simon:

--- Quote from: SiliconWizard on June 12, 2022, 06:40:02 pm ---
--- Quote from: Tomorokoshi on June 12, 2022, 03:57:41 pm ---I have an actual technical question related to this.

Consider the situation of EMC testing. When a charger ships with the product, the EMC test is done on the combination of the power supply and the product. If no power supply is shipped, the manufacturer is free to choose anything that is within the nominal specifications.

More than once in EMC testing changing the power supply resulted in the difference between passing and failing, sometimes by a quite large margin.

Therefore, it's likely that as manufacturers continue to not provide a power supply, then they will test with a top-quality "quiet" supply that give them, let's say, 10dB margin in some EMC test. If the top-quality supply sells for $20, while the cheap ones are $2, it's likely that a fair percentage of customers will get the "equivalent" cheap supply. This is already a dynamic with cell phone chargers.

--- End quote ---

You're quite right. That's a general problem with devices supporting "compatible" hardware. There is a gray area there.


--- Quote from: Tomorokoshi on June 12, 2022, 03:57:41 pm ---What does this mean for EMC testing?

--- End quote ---

Not sure it will change much.
If the manufacturer sells a device with a charger, then this exact combination has to be tested.
If it doesn't provide a charger, then it can use whatever off-the-shelf charger gives the best results during testing.
That's already the case for a majority of manufacturers offering charging through USB, whether it is micro-USB or USB-C.


--- End quote ---

commercial emc is a piece of cake at these power levels, if I can get a 5V 1A to pass military standards first time then anyone making battery charger circuitry in the phone that cannot pass commercial with any supply is not fit for their job.

Miyuki:

--- Quote from: Simon on June 13, 2022, 06:40:49 pm ---
--- Quote from: SiliconWizard on June 12, 2022, 06:40:02 pm ---
--- Quote from: Tomorokoshi on June 12, 2022, 03:57:41 pm ---I have an actual technical question related to this.

Consider the situation of EMC testing. When a charger ships with the product, the EMC test is done on the combination of the power supply and the product. If no power supply is shipped, the manufacturer is free to choose anything that is within the nominal specifications.

More than once in EMC testing changing the power supply resulted in the difference between passing and failing, sometimes by a quite large margin.

Therefore, it's likely that as manufacturers continue to not provide a power supply, then they will test with a top-quality "quiet" supply that give them, let's say, 10dB margin in some EMC test. If the top-quality supply sells for $20, while the cheap ones are $2, it's likely that a fair percentage of customers will get the "equivalent" cheap supply. This is already a dynamic with cell phone chargers.

--- End quote ---

You're quite right. That's a general problem with devices supporting "compatible" hardware. There is a gray area there.


--- Quote from: Tomorokoshi on June 12, 2022, 03:57:41 pm ---What does this mean for EMC testing?

--- End quote ---

Not sure it will change much.
If the manufacturer sells a device with a charger, then this exact combination has to be tested.
If it doesn't provide a charger, then it can use whatever off-the-shelf charger gives the best results during testing.
That's already the case for a majority of manufacturers offering charging through USB, whether it is micro-USB or USB-C.


--- End quote ---

commercial emc is a piece of cake at these power levels, if I can get a 5V 1A to pass military standards first time then anyone making battery charger circuitry in the phone that cannot pass commercial with any supply is not fit for their job.

--- End quote ---
There is a reason why chargers are made in Asia. EMC is just printing on the case. No company in US or EU will be allowed to manufacture and sell what they can do. This way distributor can just say it was a bad batch, or any other cheap excuse with no consequences even if something happens.
They commonly omit almost all filtering till it works somehow.
I for example have one charger so noisy when I connect it to the phone it just totally messes up the touchscreen (do this to multiple phones)

tooki:

--- Quote from: Miyuki on June 13, 2022, 07:07:12 pm ---I for example have one charger so noisy when I connect it to the phone it just totally messes up the touchscreen (do this to multiple phones)

--- End quote ---
It doesn’t take much, and is in no way limited to cheaply made chargers: back in 2007, when the original iPhone came out, using the same Dock connector that they’d been using on the iPod for 4 years (around 3 of which with USB charging), Apple released a new USB charger woth the iPhone, because the iPod USB chargers were too noisy and messed up the touchscreens.

I have an Amazon brand 10-port charger that causes touchscreen problems too. Eh, at least it’s OK for charging power banks and running my clock…

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod