C
Commander Kinsey
Guest
I thought the data line was used to signal what current the device requires and what the power supply or computer USB socket is capable of. But aren\'t charging cables missing the data lines?
How does USB decide charging rate? Especially if you just use a charging cable with no data lines....
T
The Natural Philosopher
Guest
On 12/11/2022 16:33, JNugent wrote:
Intelligent semiconductor circuits simply dont obey it.
--
\"Corbyn talks about equality, justice, opportunity, health care, peace,
community, compassion, investment, security, housing....\"
\"What kind of person is not interested in those things?\"
\"Jeremy Corbyn?\"
Intelligent semiconductor circuits simply dont obey it.
--
\"Corbyn talks about equality, justice, opportunity, health care, peace,
community, compassion, investment, security, housing....\"
\"What kind of person is not interested in those things?\"
\"Jeremy Corbyn?\"
J
JNugent
Guest
On 13/11/2022 10:57 am, The Natural Philosopher wrote:
Do they reduce the supplied voltage, such that V, I and R stay in balance?
Do they reduce the supplied voltage, such that V, I and R stay in balance?
P
Paul
Guest
On 11/11/2022 8:59 PM, Commander Kinsey wrote:
> I thought the data line was used to signal what current the device requires and what the power supply or computer USB socket is capable of. But aren\'t charging cables missing the data lines?
This isn\'t the whole story, but it\'ll fill in what some
of the other sites miss. USB-PD spec is another way to do it,
instead of some of these other earlier attempts.
https://obddiag.net/usb-power.html
That makes it easier to understand why
a cable might matter. As demonstrated here.
It\'s too bad the chart does not have a column
for the \"suspected charging standard\" used in each
case. If they had included some names, it would
make it easier for you to Google each
(proprietary or otherwise) standard.
https://www.extremetech.com/wp-content/uploads/2017/04/USB-FastCharging-640x419.png
Other cabling schemes may use more \"active\"
means of signaling. \"Passive\" cabling (where
there is no D+ D- continuity, but there is resistor
straps on D+ D- on the cable output end) are generally
limited to lower currents.
If you have a 1 ampere wall adapter, and you
use a \"charging cable that indicates 2 amperes\",
then plugging your iPad into that, the iPad believes
the 2 ampere resistor-strap-indication and draws
the 2 amperes, and the wall adapter... shuts off
on overcurrent. You cannot necessarily join just
any old random cable between wall adapter and device.
The combinations must be intelligently selected by the
person doing this. When using one of the active cable
standards, the hope is the automation avoids
some of the potential issues. Just because one end
of your setup supports USB PD, does not mean the other
end does. You could even join two USB PD devices
with *the wrong cable*.
If you use a USB extension cable, with just the four wires
and no resistors whatsoever, then I would expect the
charging current to be one ampere or less.
I think it would take a significant number of web page
URLs, to cover all the methods. Start Googling
Paul
> I thought the data line was used to signal what current the device requires and what the power supply or computer USB socket is capable of. But aren\'t charging cables missing the data lines?
This isn\'t the whole story, but it\'ll fill in what some
of the other sites miss. USB-PD spec is another way to do it,
instead of some of these other earlier attempts.
https://obddiag.net/usb-power.html
That makes it easier to understand why
a cable might matter. As demonstrated here.
It\'s too bad the chart does not have a column
for the \"suspected charging standard\" used in each
case. If they had included some names, it would
make it easier for you to Google each
(proprietary or otherwise) standard.
https://www.extremetech.com/wp-content/uploads/2017/04/USB-FastCharging-640x419.png
Other cabling schemes may use more \"active\"
means of signaling. \"Passive\" cabling (where
there is no D+ D- continuity, but there is resistor
straps on D+ D- on the cable output end) are generally
limited to lower currents.
If you have a 1 ampere wall adapter, and you
use a \"charging cable that indicates 2 amperes\",
then plugging your iPad into that, the iPad believes
the 2 ampere resistor-strap-indication and draws
the 2 amperes, and the wall adapter... shuts off
on overcurrent. You cannot necessarily join just
any old random cable between wall adapter and device.
The combinations must be intelligently selected by the
person doing this. When using one of the active cable
standards, the hope is the automation avoids
some of the potential issues. Just because one end
of your setup supports USB PD, does not mean the other
end does. You could even join two USB PD devices
with *the wrong cable*.
If you use a USB extension cable, with just the four wires
and no resistors whatsoever, then I would expect the
charging current to be one ampere or less.
I think it would take a significant number of web page
URLs, to cover all the methods. Start Googling
Paul
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 04:03:04 -0000, Paul <nospam@needed.invalid> wrote:
Interesting, they say \"Samsung devices require 1.2V voltage on both D+ and D- data lines\". I have a Samsung phone which will not charge off one particular 3.1A power supply, but it\'s happy with anything else. Even 500mA chargers below it\'s max current. And the weird thing is it works with a \"charging cable\" which presumably has no data lines, so it can\'t possibly need a voltage on them.
So Google and Samsung are in bed together and are pushing out anything else?
I have a Samsung A10, which no matter what I power it with it only takes 1.1A. But I don\'t have a genuine Samsung charger. Why? Because they don\'t supply them with the phone! It just says use any charger you have lying about!
I can\'t find anywhere what the max charging rate of an A10 is, amazing its not in some specs sheet somewhere! I had to use \"Ampere\", an app to monitor battery charging rate, to work out how much it was taking from various sources.
WTF? These are charging cables, specifically designed to charge! No data lines, fast charging expected!
I\'ve never found an adaptor to do that, the voltage just drops, so the charging current ends up what it should be.
But you\'d still have the resistors in the actual cable plugged into the extension cable.
I thought USB was supposed to just work.
Well I\'ve ordered a Nokia 3A charger, we\'ll see what that does.
Why the hell aren\'t all these devices using charging pads yet? An electric toothbrush I got decades ago charges by induction. It\'s not an expensive method.
Interesting, they say \"Samsung devices require 1.2V voltage on both D+ and D- data lines\". I have a Samsung phone which will not charge off one particular 3.1A power supply, but it\'s happy with anything else. Even 500mA chargers below it\'s max current. And the weird thing is it works with a \"charging cable\" which presumably has no data lines, so it can\'t possibly need a voltage on them.
So Google and Samsung are in bed together and are pushing out anything else?
I have a Samsung A10, which no matter what I power it with it only takes 1.1A. But I don\'t have a genuine Samsung charger. Why? Because they don\'t supply them with the phone! It just says use any charger you have lying about!
I can\'t find anywhere what the max charging rate of an A10 is, amazing its not in some specs sheet somewhere! I had to use \"Ampere\", an app to monitor battery charging rate, to work out how much it was taking from various sources.
WTF? These are charging cables, specifically designed to charge! No data lines, fast charging expected!
I\'ve never found an adaptor to do that, the voltage just drops, so the charging current ends up what it should be.
But you\'d still have the resistors in the actual cable plugged into the extension cable.
I think it would take a significant number of web page
URLs, to cover all the methods. Start Googling
I thought USB was supposed to just work.
Well I\'ve ordered a Nokia 3A charger, we\'ll see what that does.
Why the hell aren\'t all these devices using charging pads yet? An electric toothbrush I got decades ago charges by induction. It\'s not an expensive method.
P
Paul
Guest
On 11/12/2022 1:37 AM, Commander Kinsey wrote:
An electric toothbrush I got decades ago charges by induction.
It\'s not an expensive method.
On electronics, this is the inductive charging standard. \"Qi\"
https://en.wikipedia.org/wiki/Qi_%28standard%29
Paul
An electric toothbrush I got decades ago charges by induction.
It\'s not an expensive method.
On electronics, this is the inductive charging standard. \"Qi\"
https://en.wikipedia.org/wiki/Qi_%28standard%29
Paul
R
Ricky
Guest
On Saturday, November 12, 2022 at 2:37:14 AM UTC-4, Commander Kinsey wrote:
That is an incorrect assumption, that the charging only cable has nothing on the data pins.
It\'s a cell phone. What do you expect?
Try using your ohm meter.
Wouldn\'t the resistors be in the power unit? It makes no sense to have anything in the cable unless the currents are so high, they would overheat a typical cable.
--
Rick C.
- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
That is an incorrect assumption, that the charging only cable has nothing on the data pins.
It\'s a cell phone. What do you expect?
Try using your ohm meter.
Wouldn\'t the resistors be in the power unit? It makes no sense to have anything in the cable unless the currents are so high, they would overheat a typical cable.
--
Rick C.
- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 07:33:18 -0000, Paul <nospam@needed.invalid> wrote:
So why isn\'t it in every single phone?
So why isn\'t it in every single phone?
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 07:39:17 -0000, Ricky <gnuarm.deletethisbit@gmail.com> wrote:
Shouldn\'t there be some kind of standard for charging? It seems every manufacturer uses a different technique.
Basic specs in the fucking manual, why wouldn\'t I expect that? I can see the power consumption of my microwave by looking at the rating plate on the back.
Power unit? But what if I use a charging cable on a PC?
Just what is the difference between a charging cable and a data cable?
Shouldn\'t there be some kind of standard for charging? It seems every manufacturer uses a different technique.
Basic specs in the fucking manual, why wouldn\'t I expect that? I can see the power consumption of my microwave by looking at the rating plate on the back.
Power unit? But what if I use a charging cable on a PC?
Just what is the difference between a charging cable and a data cable?
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 07:39:17 -0000, Ricky <gnuarm.deletethisbit@gmail.com> wrote:
Charging cables have no connection on the data lines, they advertise them as being secure - you can charge your phone on an aeroplane or in a cafe without risking someone hacking into your phone. So resistors on data lines within the power supply cannot possibly do anything if you\'re using a charging cable.
So.... how does a device and power supply work out what rate to charge? In the absence of data lines, does the device just go for it flat out until the voltage drop on the power supply causes it to use less?
Charging cables have no connection on the data lines, they advertise them as being secure - you can charge your phone on an aeroplane or in a cafe without risking someone hacking into your phone. So resistors on data lines within the power supply cannot possibly do anything if you\'re using a charging cable.
So.... how does a device and power supply work out what rate to charge? In the absence of data lines, does the device just go for it flat out until the voltage drop on the power supply causes it to use less?
J
John Walliker
Guest
On Saturday, 12 November 2022 at 08:57:35 UTC, Commander Kinsey wrote:
Yes, that is exactly what happens with older chargers. Things get more complex with PD
chargers as the voltage can be negotiated. All chargers start at 5V but some can also
deliver 9V, 12V, 15V and 20V and in some cases lots of smaller steps in between.
My pixel3a phone likes to charge at 9V for example. I have a notebook PC that prefers to
charge at 20V. if it can.
Very high power USB chargers can deliver up to 48V at up to 5A giving a maximum output
power of 240W.
The more exotic combinations (more than 20V or more than 3A) will only work with special
cables that have identity chips which specify the current and voltage rating of the cable and
connectors.
John
Yes, that is exactly what happens with older chargers. Things get more complex with PD
chargers as the voltage can be negotiated. All chargers start at 5V but some can also
deliver 9V, 12V, 15V and 20V and in some cases lots of smaller steps in between.
My pixel3a phone likes to charge at 9V for example. I have a notebook PC that prefers to
charge at 20V. if it can.
Very high power USB chargers can deliver up to 48V at up to 5A giving a maximum output
power of 240W.
The more exotic combinations (more than 20V or more than 3A) will only work with special
cables that have identity chips which specify the current and voltage rating of the cable and
connectors.
John
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 11:15:00 -0000, John Walliker <jrwalliker@gmail.com> wrote:
There were some modems back in the days of USB 2, which drew about 570mA. Some motherboards were shutting the USB socket off when they did that.
Grrrr. My phone takes no more than 5V 1.1A. Takes quite a while to charge if the CPU is running flat out all 8 cores.
There were some modems back in the days of USB 2, which drew about 570mA. Some motherboards were shutting the USB socket off when they did that.
Grrrr. My phone takes no more than 5V 1.1A. Takes quite a while to charge if the CPU is running flat out all 8 cores.
W
whit3rd
Guest
On Sunday, November 13, 2022 at 3:52:24 AM UTC-8, JNugent wrote:
The phone can turn off its various functions; obviously, you turn the touchscreen and
backlight off when you pocket it. Less obviously, it turns off the battery charge circuit
when the battery is full, the radios go silent when \'airplane mode\' is selected, and
(on the rare power-down for reset purposes) even turns off its CPU, so
there\'s a delay next power-up while things reboot.
V is a constant (the charger is a voltage source) even if it can step that constant UP to
different values. I is not constant, because various switch-offs modulate power draw.
R, of course, is... undefined, unless you\'ve paid cellphone prices to
buy ... a resistor.
The phone can turn off its various functions; obviously, you turn the touchscreen and
backlight off when you pocket it. Less obviously, it turns off the battery charge circuit
when the battery is full, the radios go silent when \'airplane mode\' is selected, and
(on the rare power-down for reset purposes) even turns off its CPU, so
there\'s a delay next power-up while things reboot.
V is a constant (the charger is a voltage source) even if it can step that constant UP to
different values. I is not constant, because various switch-offs modulate power draw.
R, of course, is... undefined, unless you\'ve paid cellphone prices to
buy ... a resistor.
N
nospam
Guest
In article <op.1vii51bbmvhs6z@ryzen.home>, Commander Kinsey
<CK1@nospam.com> wrote:
usb \'charging\' cables are non-compliant with the spec so anything goes.
if the devices and chargers are also non-compliant, then you probably
will get higher rates, because they\'re not checking for anything. good
luck.
if the devices and chargers are compliant (which most are), then it\'s
either 100ma (guaranteed minimum) or possibly higher if the cable has
resistors, which are also in the charger but can\'t be seen because
there aren\'t any data wires. in other words, the cable is faking it.
the problem is that the cable has no idea what the capability of the
charger will be. a compliant charger has resistors for whatever its
maximum is, but the cable doesn\'t know what that is. for example, the
cable might indicate 500ma, when the charger is capable of more, or
worse, the cable might indicate 1a and the charger can\'t source that
much.
tl;dr - avoid \'charging\' cables.
<CK1@nospam.com> wrote:
usb \'charging\' cables are non-compliant with the spec so anything goes.
if the devices and chargers are also non-compliant, then you probably
will get higher rates, because they\'re not checking for anything. good
luck.
if the devices and chargers are compliant (which most are), then it\'s
either 100ma (guaranteed minimum) or possibly higher if the cable has
resistors, which are also in the charger but can\'t be seen because
there aren\'t any data wires. in other words, the cable is faking it.
the problem is that the cable has no idea what the capability of the
charger will be. a compliant charger has resistors for whatever its
maximum is, but the cable doesn\'t know what that is. for example, the
cable might indicate 500ma, when the charger is capable of more, or
worse, the cable might indicate 1a and the charger can\'t source that
much.
tl;dr - avoid \'charging\' cables.
J
Joe
Guest
On Sat, 12 Nov 2022 12:03:58 -0000
\"Commander Kinsey\" <CK1@nospam.com> wrote:
Surely nowadays the charger is in the device being charged, and is fed
the 5V (or whatever) directly? Lithium batteries are quite fussy about
charging, particularly fast charging. Charge rate is specific to the
battery, and the maximum current should typically be about 40-50% of the
capacity in Ah. Once the battery voltage has reached 4.2V/cell, current
is reduced to maintain 4.2V until it\'s below a certain level, again
depending on capacity. The battery temperature must also be monitored,
as the voltage is dependent on it, and also to shut down if the
temperature gets too high with a faulty battery. It makes sense to have
all this stuff physically close to the battery.
--
Joe
\"Commander Kinsey\" <CK1@nospam.com> wrote:
Surely nowadays the charger is in the device being charged, and is fed
the 5V (or whatever) directly? Lithium batteries are quite fussy about
charging, particularly fast charging. Charge rate is specific to the
battery, and the maximum current should typically be about 40-50% of the
capacity in Ah. Once the battery voltage has reached 4.2V/cell, current
is reduced to maintain 4.2V until it\'s below a certain level, again
depending on capacity. The battery temperature must also be monitored,
as the voltage is dependent on it, and also to shut down if the
temperature gets too high with a faulty battery. It makes sense to have
all this stuff physically close to the battery.
--
Joe
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 14:06:59 -0000, Joe <joe@jretrading.com> wrote:
Yes but I\'m talking about how much current can come in at 5V from the source outside the device, and how the device and the source negotiate this.
Actually they\'re very simple, akin to lead acid. No nonsense about sensing delta V like Nickel ones. I charge lithium with a bench charger, you set the voltage to 4.2, and the current to 1C (as in 3 amps for a 3Ah battery). There\'s no need to go slower than a 1 hour charge.
No, 100%.
Nah, you just need limited current at 1C, and voltage limited to 4.2V.
Yes but I\'m talking about how much current can come in at 5V from the source outside the device, and how the device and the source negotiate this.
Actually they\'re very simple, akin to lead acid. No nonsense about sensing delta V like Nickel ones. I charge lithium with a bench charger, you set the voltage to 4.2, and the current to 1C (as in 3 amps for a 3Ah battery). There\'s no need to go slower than a 1 hour charge.
No, 100%.
Nah, you just need limited current at 1C, and voltage limited to 4.2V.
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 16:59:45 -0000, JNugent <jenningsandco@mail.com> wrote:
Why would ohms law limit anything to 1 amp if they\'ve designed it properly?
Why would ohms law limit anything to 1 amp if they\'ve designed it properly?
C
Commander Kinsey
Guest
On Sat, 12 Nov 2022 17:10:37 -0000, Joe <joe@jretrading.com> wrote:
ARGH!
How absurd. If the CPU is drawing half an amp, the half an amp isn\'t getting into the battery chemistry obviously. It\'s being powered by the external supply. They should be measuring the charging current right at the battery.
ARGH!
How absurd. If the CPU is drawing half an amp, the half an amp isn\'t getting into the battery chemistry obviously. It\'s being powered by the external supply. They should be measuring the charging current right at the battery.
J
JNugent
Guest
On 12/11/2022 12:03 pm, Commander Kinsey wrote:
Ohm\'s law?
Ohm\'s law?
P
Peeler
Guest
On Sat, 12 Nov 2022 14:06:59 +0000, Joe, another demented, troll-feeding,
senile ASSHOLE, blathered:
Surely the dumb Scottish wanker managed to bait you yet again, troll-feeding
senile twit!
senile ASSHOLE, blathered:
Surely the dumb Scottish wanker managed to bait you yet again, troll-feeding
senile twit!