Does it make any difference on output amperage if output voltage is the same in wall plug/USB charger adapters? Referring to 1 amp vs 1.8 amps. Former is for iPhone & latter for Kindle Fire HD. Was hoping to use one of these adapters rather than having to buy another one for Samsung Intensity II phone. Both have 5 volts output.

On Friday, September 6, 2013 8:23:21 AM UTC-4, Frank Thompson wrote:
Does it make any difference on output amperage if output voltage is the same in wall plug/USB charger adapters? Referring to 1 amp vs 1.8 amps. Former is for iPhone & latter for Kindle Fire HD. Was hoping to use one of these adapters rather than having to buy another one for Samsung Intensity II phone. Both have 5 volts output.

As long as the replacement has at least as many amps as the
original you're OK.

Frank,

The output amperage is the maximum output that your power supply will put
out. As long as that amperage exceeds the needs of the powered device,
you'll be fine. So, the Kindle 5 v charger will work with the phone. The
phone 5v charger may not work with the Kindle and may get hot et c..

Dave M.

On 9/6/2013 7:23 AM, Frank Thompson wrote:
Does it make any difference on output amperage if output voltage is
the same in wall plug/USB charger adapters? Referring to 1 amp vs
1.8 amps. Former is for iPhone & latter for Kindle Fire HD. Was
hoping to use one of these adapters rather than having to buy
another one for Samsung Intensity II phone. Both have 5 volts
output.


Most of the 5 volt "wall warts" with 2.5mm plugs that are made for
powering and charging smart phones and tablets are rated at 2 amps
or 2,000ma output, at least all those I've seen. I have to order a
charger for a tablet that has a 2.5mm plug because that tiny plug is not
that common yet as is the ubiquitous 3.5mm plug and is very hard to find
locally. O_o

TDD

Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.

..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 9/6/2013 9:08 AM, The Daring Dufas wrote:

Most of the 5 volt "wall warts" with 2.5mm plugs that are made for
powering and charging smart phones and tablets are rated at 2 amps
or 2,000ma output, at least all those I've seen. I have to order a
charger for a tablet that has a 2.5mm plug because that tiny plug is not
that common yet as is the ubiquitous 3.5mm plug and is very hard to find
locally. O_o

TDD

On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD

On 9/6/2013 9:50 AM, The Daring Dufas wrote:
On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD


Actually it appears that most new cell phones are standardizing on Micro
USB. So it is nice to be able to use cig lighter to USB or wall wart to
USB chargers and a separate cable, then if you need to hook to a PC you
can as well. Only downside is USB current spec is 500 mA and lots of
devices can charge faster than that; there's ways around it (connecting
two pins together to let the device know that it's plugged into a
charger not a PC etc. to select charge rate) but sometimes mixing and
matching parts will result in a slower than desired charge rate. I
actually had issues with that on an old HTC Evo; when using on the car
charger it would discharge faster than it would charge while running a
GPS enabled app (Waze, Trapster, Telenav etc.) so if I wanted to use the
phone for navigation on a road trip I'd have to carry several spare
batteries with me. Haven't had that problem yet on newer Motorola smart
phones.

nate

Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.

If they are usable, they will sell fast at goodwill, so donate them. I just
bought an old verison phone there for $5 to use on the pageplus by-the-minute
plan.

On 9/6/2013 8:57 AM, Nate Nagel wrote:
On 9/6/2013 9:50 AM, The Daring Dufas wrote:
On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD


Actually it appears that most new cell phones are standardizing on Micro
USB. So it is nice to be able to use cig lighter to USB or wall wart to
USB chargers and a separate cable, then if you need to hook to a PC you
can as well. Only downside is USB current spec is 500 mA and lots of
devices can charge faster than that; there's ways around it (connecting
two pins together to let the device know that it's plugged into a
charger not a PC etc. to select charge rate) but sometimes mixing and
matching parts will result in a slower than desired charge rate. I
actually had issues with that on an old HTC Evo; when using on the car
charger it would discharge faster than it would charge while running a
GPS enabled app (Waze, Trapster, Telenav etc.) so if I wanted to use the
phone for navigation on a road trip I'd have to carry several spare
batteries with me. Haven't had that problem yet on newer Motorola smart
phones.

nate

I like the fact that USB with its different size plugs is becoming a
standard power/data transmission method but there are still a lot of
variations that are maddening. There are adapters for different plug
sizes but the way they're wired can be different which I've found to
be quite irritating. O_o

TDD

On 9/6/2013 5:23 AM, Frank Thompson wrote:
Does it make any difference on output amperage if output voltage is the same in wall plug/USB charger adapters? Referring to 1 amp vs 1.8 amps. Former is for iPhone & latter for Kindle Fire HD. Was hoping to use one of these adapters rather than having to buy another one for Samsung Intensity II phone. Both have 5 volts output.

Yes and no.

The manufacturers do some strange things with the data pins to indicate
that the device is capable of charging at.

For the iPhone and iPad, 2.0V on both data pins tells the iPhone to
charge at 500mA. 2.8V on D- and 2.0V on D+ tells the iPhone to charge at
1000mA. 2.0V on D- and 2.8V on D+ indicates 2000mA and is for the iPad.

This system is designed to prevent polyfuses from opening on chargers
and computers. If you plugged an iPad into a computer's USB port, and
used a cable that tried to trick the iPad into charging at 2000mA, the
port would shut down. At 500mA the iPad will charge (at least if it's
turned off; if it's on then it will discharge, but more slowly).

The key thing to remember is that Apple devices will NOT charge just
with 5V on USB pin 1 and GND on USB pin 4. They _must_ see a DC voltage
on pin 2 (D-) and pin 3 (D+). A Google Nexus 7 tablet (at least the
first generation) will NOT charge just with 5V on USB pin 1 and GND on
USB pin 4, the data pins must be shorted. This applies only for
chargers, not for a computer's USB port.

On my Google Nexus 7, unless I short the data pins together it won't
charge at all from a USB charger (it will charge at a slow rate from a
computer or at a fast rate from the supplied charger). So I made up a
bunch of cables with the data wires shorted so I can use a high-current
car charger or high-current wall wart. Of course these cables can't be
used for data transfer anymore.

The question is, "what does the Kindle HD do with pins 2 & 3? Does it
short them together for high speed charging? Or do they have a scheme
similar to Apple's? I could not find any information on what Lab126 did
regarding this.

On Fri, 06 Sep 2013 08:08:58 -0500, The Daring Dufas
wrote:

On 9/6/2013 7:23 AM, Frank Thompson wrote:
Does it make any difference on output amperage if output voltage is
the same in wall plug/USB charger adapters? Referring to 1 amp vs
1.8 amps. Former is for iPhone & latter for Kindle Fire HD. Was
hoping to use one of these adapters rather than having to buy
another one for Samsung Intensity II phone. Both have 5 volts
output.


Most of the 5 volt "wall warts" with 2.5mm plugs that are made for
powering and charging smart phones and tablets are rated at 2 amps
or 2,000ma output, at least all those I've seen. I have to order a
charger for a tablet that has a 2.5mm plug because that tiny plug is not
that common yet as is the ubiquitous 3.5mm plug and is very hard to find
locally. O_o

TDD
He DID say USB charger - and the standard USB A cable fits virtually
all of the cahargers from the crappy 500ma chinese junk to the best
2.5 or 3 amp (usb3 - usually) chargers. Big works on small, but small
doesn't work on big. Usually you can get away with the small one to
charge something bigger if the something bigger is turned off - but
don't count on it.

On Fri, 06 Sep 2013 09:57:34 -0400, Nate Nagel
wrote:

On 9/6/2013 9:50 AM, The Daring Dufas wrote:
On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD


Actually it appears that most new cell phones are standardizing on Micro
USB. So it is nice to be able to use cig lighter to USB or wall wart to
USB chargers and a separate cable, then if you need to hook to a PC you
can as well. Only downside is USB current spec is 500 mA and lots of
devices can charge faster than that; there's ways around it (connecting
two pins together to let the device know that it's plugged into a
charger not a PC etc. to select charge rate) but sometimes mixing and
matching parts will result in a slower than desired charge rate. I
actually had issues with that on an old HTC Evo; when using on the car
charger it would discharge faster than it would charge while running a
GPS enabled app (Waze, Trapster, Telenav etc.) so if I wanted to use the
phone for navigation on a road trip I'd have to carry several spare
batteries with me. Haven't had that problem yet on newer Motorola smart
phones.

nate
USB2 power (charge) spec is 2 amps.

On Fri, 06 Sep 2013 10:21:41 -0500, The Daring Dufas
wrote:

On 9/6/2013 8:57 AM, Nate Nagel wrote:
On 9/6/2013 9:50 AM, The Daring Dufas wrote:
On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD


Actually it appears that most new cell phones are standardizing on Micro
USB. So it is nice to be able to use cig lighter to USB or wall wart to
USB chargers and a separate cable, then if you need to hook to a PC you
can as well. Only downside is USB current spec is 500 mA and lots of
devices can charge faster than that; there's ways around it (connecting
two pins together to let the device know that it's plugged into a
charger not a PC etc. to select charge rate) but sometimes mixing and
matching parts will result in a slower than desired charge rate. I
actually had issues with that on an old HTC Evo; when using on the car
charger it would discharge faster than it would charge while running a
GPS enabled app (Waze, Trapster, Telenav etc.) so if I wanted to use the
phone for navigation on a road trip I'd have to carry several spare
batteries with me. Haven't had that problem yet on newer Motorola smart
phones.

nate

I like the fact that USB with its different size plugs is becoming a
standard power/data transmission method but there are still a lot of
variations that are maddening. There are adapters for different plug
sizes but the way they're wired can be different which I've found to
be quite irritating. O_o

TDD
USB is a standard. Any charger or device with a USB A plug will be
wired the same. Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

On 9/6/2013 10:28 AM, wrote:

snip

USB is a standard. Any charger or device with a USB A plug will be
wired the same.

If only that were true! Well the first part is true, USB is a standard.

The second part is, unfortunately, not true.

What _is_ true, is that the +5 and GND pins will be wired the same. But
what often matters is how the data pins are wired. Apple has a specific
standard for the data pins based on how much current the charger can
supply. Other manufacturers do different things. For example Asus, on
the Google Nexus 7, requires that the data pins be shorted together to
charge from a charger (not from a PC of course).

Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

It's possible to construct a cable that works, or in some cases, buy a
cable that has been modified so the data pins are correctly wired. You
can also modify the charger, i.e.
http://www.instructables.com/id/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone/.

On 9/6/2013 12:47 PM, sms wrote:
On 9/6/2013 10:28 AM, wrote:

snip

USB is a standard. Any charger or device with a USB A plug will be
wired the same.

If only that were true! Well the first part is true, USB is a standard.

The second part is, unfortunately, not true.


That's what I've run into. O_o

What _is_ true, is that the +5 and GND pins will be wired the same. But
what often matters is how the data pins are wired. Apple has a specific
standard for the data pins based on how much current the charger can
supply. Other manufacturers do different things. For example Asus, on
the Google Nexus 7, requires that the data pins be shorted together to
charge from a charger (not from a PC of course).

Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

It's possible to construct a cable that works, or in some cases, buy a
cable that has been modified so the data pins are correctly wired. You
can also modify the charger, i.e.
http://www.instructables.com/id/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone/.


I hope somebody will produce a jumper box like I have for RS-232/422/xxx
for USB so I can get things to function when I'm working on or testing
something. ^_^

TDD

On Fri, 06 Sep 2013 10:21:41 -0500, The Daring Dufas
wrote:

On 9/6/2013 8:57 AM, Nate Nagel wrote:
On 9/6/2013 9:50 AM, The Daring Dufas wrote:
On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD


Actually it appears that most new cell phones are standardizing on Micro
USB. So it is nice to be able to use cig lighter to USB or wall wart to
USB chargers and a separate cable, then if you need to hook to a PC you
can as well. Only downside is USB current spec is 500 mA and lots of
devices can charge faster than that; there's ways around it (connecting
two pins together to let the device know that it's plugged into a
charger not a PC etc. to select charge rate) but sometimes mixing and
matching parts will result in a slower than desired charge rate. I
actually had issues with that on an old HTC Evo; when using on the car
charger it would discharge faster than it would charge while running a
GPS enabled app (Waze, Trapster, Telenav etc.) so if I wanted to use the
phone for navigation on a road trip I'd have to carry several spare
batteries with me. Haven't had that problem yet on newer Motorola smart
phones.

nate

I like the fact that USB with its different size plugs is becoming a
standard power/data transmission method but there are still a lot of
variations that are maddening. There are adapters for different plug
sizes but the way they're wired can be different which I've found to
be quite irritating. O_o

USB might be a standard but for chargers everyone has their own twist
on the theme. Some USB chargers WILL NOT work with some appliances.
Some will assume they're connected to a USB port (.5A) even though the
supply is capable of much more. There is a big market in the industry
for chips that understand everyone's charging twist (and for those
who've figured out how to make this stuff programmable).

That's the nice thing about standards; there are *so* many to choose
from. USB is no different (and it's getting worse).

On 9/6/2013 12:24 PM, wrote:
On Fri, 06 Sep 2013 08:08:58 -0500, The Daring Dufas
wrote:

On 9/6/2013 7:23 AM, Frank Thompson wrote:
Does it make any difference on output amperage if output voltage is
the same in wall plug/USB charger adapters? Referring to 1 amp vs
1.8 amps. Former is for iPhone & latter for Kindle Fire HD. Was
hoping to use one of these adapters rather than having to buy
another one for Samsung Intensity II phone. Both have 5 volts
output.


Most of the 5 volt "wall warts" with 2.5mm plugs that are made for
powering and charging smart phones and tablets are rated at 2 amps
or 2,000ma output, at least all those I've seen. I have to order a
charger for a tablet that has a 2.5mm plug because that tiny plug is not
that common yet as is the ubiquitous 3.5mm plug and is very hard to find
locally. O_o

TDD
He DID say USB charger - and the standard USB A cable fits virtually
all of the cahargers from the crappy 500ma chinese junk to the best
2.5 or 3 amp (usb3 - usually) chargers. Big works on small, but small
doesn't work on big. Usually you can get away with the small one to
charge something bigger if the something bigger is turned off - but
don't count on it.


OOPS! Looks like one of my eyeballs was looking in the other direction,
the one that works. I overlooked USB and thought it was a 2.5mm round
plug like the one that's on the 7" tablet I have but it also has a micro
USB connection but I don't think it can get power over it. Premature
postification, it happens sometimes to all us guys when we get excited. O_o

TDD

On 9/6/2013 11:36 AM, The Daring Dufas wrote:
On 9/6/2013 12:47 PM, sms wrote:
On 9/6/2013 10:28 AM, wrote:

snip

USB is a standard. Any charger or device with a USB A plug will be
wired the same.

If only that were true! Well the first part is true, USB is a standard.

The second part is, unfortunately, not true.


That's what I've run into. O_o

What _is_ true, is that the +5 and GND pins will be wired the same. But
what often matters is how the data pins are wired. Apple has a specific
standard for the data pins based on how much current the charger can
supply. Other manufacturers do different things. For example Asus, on
the Google Nexus 7, requires that the data pins be shorted together to
charge from a charger (not from a PC of course).

Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

It's possible to construct a cable that works, or in some cases, buy a
cable that has been modified so the data pins are correctly wired. You
can also modify the charger, i.e.
http://www.instructables.com/id/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone/.



I hope somebody will produce a jumper box like I have for RS-232/422/xxx
for USB so I can get things to function when I'm working on or testing
something. ^_^

LOL, you're showing your age! I once built one of those RS-232 boxes
using comparators and a green and red LED for each channel (prior to the
availability of dual color LEDs, though I liked having the third state
(no LED on).

On 9/6/2013 3:22 PM, sms wrote:
On 9/6/2013 11:36 AM, The Daring Dufas wrote:
On 9/6/2013 12:47 PM, sms wrote:
On 9/6/2013 10:28 AM, wrote:

snip

USB is a standard. Any charger or device with a USB A plug will be
wired the same.

If only that were true! Well the first part is true, USB is a standard.

The second part is, unfortunately, not true.


That's what I've run into. O_o

What _is_ true, is that the +5 and GND pins will be wired the same. But
what often matters is how the data pins are wired. Apple has a specific
standard for the data pins based on how much current the charger can
supply. Other manufacturers do different things. For example Asus, on
the Google Nexus 7, requires that the data pins be shorted together to
charge from a charger (not from a PC of course).

Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

It's possible to construct a cable that works, or in some cases, buy a
cable that has been modified so the data pins are correctly wired. You
can also modify the charger, i.e.
http://www.instructables.com/id/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone/.




I hope somebody will produce a jumper box like I have for RS-232/422/xxx
for USB so I can get things to function when I'm working on or testing
something. ^_^

LOL, you're showing your age! I once built one of those RS-232 boxes
using comparators and a green and red LED for each channel (prior to the
availability of dual color LEDs, though I liked having the third state
(no LED on).


I still use serial RS-232 connections for programming and control of
some equipment but I've noticed little USB connectors showing up on
newer models. Ask a young computer geek about RS-232 and he will look
at you like you just handed him a rotary dial telephone. ^_^

TDD

sms wrote:


On my Google Nexus 7, unless I short the data pins together it won't
charge at all from a USB charger

Huh? Even Google says you can use other chargers. You just have to
use the correct amperage or you may get a slow or no charge.

"If you're using a charger rated less than the one that came with your
tablet, your tablet may charge very slowly, or may not charge at all."

https://support.google.com/nexus/7/answer/2668668?hl=en

To check I just took 5 random chargers out of the junk drawer and my
Nexus 7s (both old and new models) charged from all of them using a
generic cable.

So I made up a bunch of cables with the data wires shorted so I can use a high-current
car charger or high-current wall wart. Of course these cables can't be
used for data transfer anymore.

You seem to have wasted your time...

Your timing is perfect. I have a couple old
cell phones I'd planned to pitch out. Some
agencies collect them, to give to needy
people.

Thank you.

..
Christopher A. Young
Learn about Jesus
www.lds.org
..

On 9/6/2013 10:23 AM, Bob F wrote:
If they are usable, they will sell fast at goodwill, so donate them. I just
bought an old verison phone there for $5 to use on the pageplus by-the-minute
plan.

On Fri, 06 Sep 2013 10:47:48 -0700, sms
wrote:

On 9/6/2013 10:28 AM, wrote:

snip

USB is a standard. Any charger or device with a USB A plug will be
wired the same.

If only that were true! Well the first part is true, USB is a standard.

The second part is, unfortunately, not true.

What _is_ true, is that the +5 and GND pins will be wired the same. But
what often matters is how the data pins are wired. Apple has a specific
standard for the data pins based on how much current the charger can
supply. Other manufacturers do different things. For example Asus, on
the Google Nexus 7, requires that the data pins be shorted together to
charge from a charger (not from a PC of course).

Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

It's possible to construct a cable that works, or in some cases, buy a
cable that has been modified so the data pins are correctly wired. You
can also modify the charger, i.e.
http://www.instructables.com/id/Modify-a-cheap-USB-charger-to-feed-an-iPod-iPhone/.
Apple is notorious for thumbing it's nose at standards - but even
apple uses the data lines as data lines and the power lines as power
lines. The "smart charge" feature would only work on apple spec
chargers. The "standard" works on computers, using them to charge
apple devices because the computer power supply meets the "standard"

You are saying the cable connecting from the charger to the device
needs the data pins shorted for the Nexus 7 to accept the charge, or
the nexus shorts the data pins to turn on the charger? If it needs
the pins shorted for the charger but not for the computer, it sounds
like it is controlling the "specific" charger which is not a USB
device but uses the USB plug?

On 9/6/2013 1:36 PM, The Daring Dufas wrote:

I still use serial RS-232 connections for programming and control of
some equipment but I've noticed little USB connectors showing up on
newer models. Ask a young computer geek about RS-232 and he will look
at you like you just handed him a rotary dial telephone. ^_^

Yes, the serial interface is still widely used in industrial equipment.
I keep an old laptop with serial and parallel ports to use for that sort
of stuff.

I was once an applications engineer for the company that provided about
1/2 the RS-232/parallel port/floppy controller/keyboard controller. Some
good geeky stories about that job.

On 9/6/2013 2:06 PM, AL wrote:

Huh? Even Google says you can use other chargers. You just have to
use the correct amperage or you may get a slow or no charge.

No, that's not the way it works. If you plug the Nexus 7 (the original
anyway) into a USB port that only supplies +5V and ground it will not
charge at all. If you short the data pins together it charges at maximum
current (shows up like an AC charger). If you plug it into the USB port
of a computer it will charge at 500mA.

So I made up a bunch of cables with the data wires shorted so I can use a high-current
car charger or high-current wall wart. Of course these cables can't be
used for data transfer anymore.

You seem to have wasted your time...

Nope. Without those cables the tablet would not charge at all. I had
some 2.1A car chargers and wondered why they didn't work at all. Once I
used a cable with shorted data pins it all worked fine.

What did happen is that with Android 4.2 there is no longer a need for
the special cables. But I am running 4.1 (ICS) because there are apps
that won't work on 4.2 (JB).

On 9/6/2013 2:43 PM, wrote:

Apple is notorious for thumbing it's nose at standards - but even
apple uses the data lines as data lines and the power lines as power
lines.

A charger with a USB socket doesn't send data back and forth. The Apple
chargers (and aftermarket chargers for Apple devices) follow Apple's
"standard" for telling the iOS device the available current by setting
the voltage levels of the data pins. Plug the same Apple cable into the
USB port of a computer and the computer communicates with the iDevice to
set the charge rate at 500mA.

The "smart charge" feature would only work on apple spec
chargers.

That's true, but all the aftermarket chargers just copy what Apple dows
since it's not difficult.

The "standard" works on computers, using them to charge
apple devices because the computer power supply meets the "standard"

No, the standard works on computers because the computer communicates
with the Apple device and negotiates a charging rate.

You are saying the cable connecting from the charger to the device
needs the data pins shorted for the Nexus 7 to accept the charge, or
the nexus shorts the data pins to turn on the charger?

The supplied charger has the data pins shorted. Aftermarket chargers do not.

However it should be pointed out that with the Android 4.2 (Jelly Bean)
update this is no longer the case. I am running Android 4.1 (Ice Cream
Sandwich) on my Nexus 7 because there are apps I use that won't work
under Jelly Bean).

If it needs
the pins shorted for the charger but not for the computer, it sounds
like it is controlling the "specific" charger which is not a USB
device but uses the USB plug?

No.

On 9/6/2013 6:01 PM, sms wrote:
On 9/6/2013 1:36 PM, The Daring Dufas wrote:

I still use serial RS-232 connections for programming and control of
some equipment but I've noticed little USB connectors showing up on
newer models. Ask a young computer geek about RS-232 and he will look
at you like you just handed him a rotary dial telephone. ^_^

Yes, the serial interface is still widely used in industrial equipment.
I keep an old laptop with serial and parallel ports to use for that sort
of stuff.

I was once an applications engineer for the company that provided about
1/2 the RS-232/parallel port/floppy controller/keyboard controller. Some
good geeky stories about that job.


My old Dell laptop with a serial port died and I haven't had time (code
for lazy) to fix it so I'm using a USB to serial adapter with one of my
newer old laptops to program routers, switches and phone systems. The
Domino's Pizza stores once had dumb terminals and serial connections
back to a server for order taking and I did a lot of serial networking
back then. Along with the 1A2 phone systems the stores ran fairly well
but the employees kept dropping the keyboards on to the floor and losing
the buttons. Some of those kids were so stupid they swept the buttons up
and threw them in the garbage. The old 1A2 phones were so robust you
could beat a robber to death with one of them then use it to call the
cops. I rebuilt a lot of those old systems and servers with the 8 port
serial cards in the office computers and a dial-up modems to send info
to the corporate office. I still have some of that stuff around and it
still works. ^_^

TDD

On Fri, 06 Sep 2013 16:19:07 -0700, sms
wrote:

On 9/6/2013 2:43 PM, wrote:

Apple is notorious for thumbing it's nose at standards - but even
apple uses the data lines as data lines and the power lines as power
lines.

A charger with a USB socket doesn't send data back and forth. The Apple
chargers (and aftermarket chargers for Apple devices) follow Apple's
"standard" for telling the iOS device the available current by setting
the voltage levels of the data pins. Plug the same Apple cable into the
USB port of a computer and the computer communicates with the iDevice to
set the charge rate at 500mA.

The "smart charge" feature would only work on apple spec
chargers.

That's true, but all the aftermarket chargers just copy what Apple dows
since it's not difficult.

The "standard" works on computers, using them to charge
apple devices because the computer power supply meets the "standard"

No, the standard works on computers because the computer communicates
with the Apple device and negotiates a charging rate.

If there is no apple software installed on the computer there is no
data passed between the computer and the apple device with regard to
charging rate, so the USB port on the computer provides it's
standardized 5 volts.
(
You are talking about the 5 pin micro/mini usb standard that has an
ID pin (pin 4) which is either grounded or not grounded for host or
slave ID . It is NOT the data pins that are shorted. Normal USB A
and USB B is a 4 pin connector, + and - 5volts, and Data + and Data.
-..

You are saying the cable connecting from the charger to the device
needs the data pins shorted for the Nexus 7 to accept the charge, or
the nexus shorts the data pins to turn on the charger?

The supplied charger has the data pins shorted. Aftermarket chargers do not.

The supplied charger has the charging cable hard wired to the charger
and has a 5 pin mini or micro USB plug with the ID pin grounded to
indicate it is a "host" device - making the Android device or iOS
device the "slave" device. The "slave" device then knows it is
attached to a device specific charger and sets itself accordingly.

Without the grounded id, it sees itself as the host, and sets itself
accordingly. Using a generic USB charger or a PC USB A port with a
normal USB a to Micro or mini usb cable, there is no grounded ID pin.

It is still all part of the (extended) usb standard.

Under USB 2 and 3 there is a battery charging specification which
specifies how much current the ports must be able to supply - 1.5 amps
per port and maximum 5 amps on USB2 BCS 1.2, and as high as 2 amps per
port under 3.1

However it should be pointed out that with the Android 4.2 (Jelly Bean)
update this is no longer the case. I am running Android 4.1 (Ice Cream
Sandwich) on my Nexus 7 because there are apps I use that won't work
under Jelly Bean).

If it needs
the pins shorted for the charger but not for the computer, it sounds
like it is controlling the "specific" charger which is not a USB
device but uses the USB plug?

No.

sms wrote:

On 9/6/2013 2:06 PM, AL wrote:

Huh? Even Google says you can use other chargers. You just have to
use the correct amperage or you may get a slow or no charge.

No, that's not the way it works. If you plug the Nexus 7 (the original
anyway) into a USB port that only supplies +5V and ground it will not
charge at all.

Of course that's the way it works. *I repeat myself*:
Google says so and I just checked it out with a bunch of my old
generic chargers on my own 2 Nexus 7s (original and current model) and
they *do* charge.

Heck even my iPad and iPhones charge on generic chargers. Now that
would be a switch if Apple stuff could use a generic charger and
Google tablets went proprietary and couldn't... 8-O

If you short the data pins together it charges at maximum
current (shows up like an AC charger).

As long as I use the correct size generic charger, both models charge
at max.

What did happen is that with Android 4.2 there is no longer a need for
the special cables.

Aha!!! Say that again. "no longer a need for the special cables".
Thank you. Boy that took awhile to come out, huh...

But I am running 4.1 (ICS) because there are apps
that won't work on 4.2 (JB).

So I guess that instead of posting this misleading statement:

On my Google Nexus 7, unless I short the data pins together
it won't charge at all from a USB charger"

You really meant to post:

On *my own personal Nexus 7* I chose to remain with an obsolete
version of the OS in order to run some old apps and for this reason
*I* can't use a generic charger on *my* Nexus 7.

But for those who don't have a Nexus 7 and might be thinking of
getting one, Google has long since updated all (2012 and 2013 models)
to Android 4.3 and they will work just fine on a generic charger of
the correct size... no cable hacking required.

On Fri, 06 Sep 2013 13:28:02 -0400, wrote:

On Fri, 06 Sep 2013 10:21:41 -0500, The Daring Dufas
wrote:

On 9/6/2013 8:57 AM, Nate Nagel wrote:
On 9/6/2013 9:50 AM, The Daring Dufas wrote:
On 9/6/2013 8:29 AM, Stormin Mormon wrote:
Amazing, the supply not caught up with the
demand. Of course, you can likely find them
on Ebay or Amazon.

I think standardizing is a good thing. Less
crap in the landfill. I've got several old
cell phones, and each comes with a box, manual,
batteries, charge plug, and, and, and.


All my Nokia phones can use the same charger unless it has the micro USB
plug. ^_^

TDD


Actually it appears that most new cell phones are standardizing on Micro
USB. So it is nice to be able to use cig lighter to USB or wall wart to
USB chargers and a separate cable, then if you need to hook to a PC you
can as well. Only downside is USB current spec is 500 mA and lots of
devices can charge faster than that; there's ways around it (connecting
two pins together to let the device know that it's plugged into a
charger not a PC etc. to select charge rate) but sometimes mixing and
matching parts will result in a slower than desired charge rate. I
actually had issues with that on an old HTC Evo; when using on the car
charger it would discharge faster than it would charge while running a
GPS enabled app (Waze, Trapster, Telenav etc.) so if I wanted to use the
phone for navigation on a road trip I'd have to carry several spare
batteries with me. Haven't had that problem yet on newer Motorola smart
phones.

nate

I like the fact that USB with its different size plugs is becoming a
standard power/data transmission method but there are still a lot of
variations that are maddening. There are adapters for different plug
sizes but the way they're wired can be different which I've found to
be quite irritating. O_o

TDD
USB is a standard. Any charger or device with a USB A plug will be
wired the same. Then you use a "standard" USB a to usb micro, or mini,
or special, cable as required by the device

*NOT* true. USB is a "standard" but fewer and fewer are following the
standard for charging appliances. More and more are doing an "Apple"
and rolling their own, using the same connector. Some will charge on
a standard USB port, some won't.

On Fri, 06 Sep 2013 16:19:07 -0700, sms
wrote:

On 9/6/2013 2:43 PM, wrote:

Apple is notorious for thumbing it's nose at standards - but even
apple uses the data lines as data lines and the power lines as power
lines.

A charger with a USB socket doesn't send data back and forth. The Apple
chargers (and aftermarket chargers for Apple devices) follow Apple's
"standard" for telling the iOS device the available current by setting
the voltage levels of the data pins. Plug the same Apple cable into the
USB port of a computer and the computer communicates with the iDevice to
set the charge rate at 500mA.

The "smart charge" feature would only work on apple spec
chargers.

That's true, but all the aftermarket chargers just copy what Apple dows
since it's not difficult.

The aftermarket can only copy Apple after Apple ships their stuff.
Apple will change their "standard" without telling anyone. There are
now manufacturers who supply charge controllers with programmable
charging profiles to cover future Apple (and others') products.

The "standard" works on computers, using them to charge
apple devices because the computer power supply meets the "standard"

No, the standard works on computers because the computer communicates
with the Apple device and negotiates a charging rate.

Only within the USB standard. Few, if any, computers know about the
Apple "enhancements" to USB. Again, Apple isn't alone, here.