Does it make any difference on output amperage if output voltage is the sam
e in wall plug/USB charger adapters? Referring to 1 amp vs 1.8 amps. Forme
r is for iPhone & latter for Kindle Fire HD. Was hoping to use one of thes
e adapters rather than having to buy another one for Samsung Intensity II p
hone. Both have 5 volts output.
On Friday, September 6, 2013 8:23:21 AM UTC-4, Frank Thompson wrote:
ame in wall plug/USB charger adapters? Referring to 1 amp vs 1.8 amps. For
mer is for iPhone & latter for Kindle Fire HD. Was hoping to use one of th
ese 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.
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..
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
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
On 9/6/2013 9:08 AM, The Daring Dufas wrote:
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
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
On 9/6/2013 10:28 AM, firstname.lastname@example.org wrote:
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).
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.
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. ^_^
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
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. ^_^
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 2:43 PM, email@example.com wrote:
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.
That's true, but all the aftermarket chargers just copy what Apple dows
since it's not difficult.
No, the standard works on computers because the computer communicates
with the Apple device and negotiates a charging rate.
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 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.
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
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.
Only within the USB standard. Few, if any, computers know about the
Apple "enhancements" to USB. Again, Apple isn't alone, here.
On Fri, 06 Sep 2013 13:28:02 -0400, firstname.lastname@example.org wrote:
*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.
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