On 22/06/2020 21:36, David Higton wrote:
> In message 
>            Chris Green  wrote:
>
>> Scott Alfter  wrote:
>>> In article , Chris Green  
>>> wrote:
>>>> All I'm saying is that the USB standard doesn't provide even 2 amps.
>>>> Thus a 'USB' cable that conforms to the USB specification doesn't need
>>>> to be able to carry that much current.
>>>>
>>>> If a Pi requires more than the USB specification allows then its power
>>>> supply *and* cable are "more than USB".
>>>
>>> We blew past the 500 mA limit long ago, well before the introduction of
>>> the Raspberry Pi.  The iPhone was out 5 years earlier and needed 1 A for
>>> full-rate charging.  By the time the Raspberry Pi was introduced, there
>>> was a rather large field of devices needing 1, 1.5, 2, or more amps to
>>> run and/or charge.  The tricks used to signal current draw with only
>>> passive components have even been added to the USB specs, so they really
>>> aren't "more than USB," as you put it.
>>>
>> No, but a USB 2.0 cable that also has data lines really only has to carry
>> 500mA to be 'to spec.'.
>
> Sorry, but that simply isn't true.  The USB specs say quite a lot about
> USB cables - it's all freely available to the general public, so I
> recommend that you download at least one of the specs and read the
> section on cables.
>
> You may well realise, after you do so, that lots of "USB cables" out
> there really don't conform with the USB specifications.  A lot of them
> are clearly too thin.
>
Yes. I had a 5 metre one so as to get a TV dongle near the TV socket.
Randomly it would stop working. Probably too much V drop
Same dongle on 1 meter cable is flawless

> David
>


--
"First, find out who are the people you can not criticise. They are your
oppressors."
      - George Orwell

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