(Yes I mention android development but this is regarding a 'general' topic)
As an android app developer, it's pretty much mandatory that I have my devices plugged into the computer for ADB. However, with wifi / bluetooth / GPS / screen brightness turned on or cranked up, I also need to have the device plugged into something that provides more than the measly 500mA that the computer's USB port can provide. From what I've been able to gather, the USB standard requires that USB hubs and ports cannot supply more than 500mA to a connected device. However, I suspect that there are manufacturers out there that are aware of the need for simultaneous charging + connectivity and have made special cables specifically for this (What I'm thinking of is a Y usb cable where one end plugs into the device, one plugs into the computer and only uses the data wires, and the other plugs into the charger which feeds and charges the device.) Do any of you know if something like this exists and where I can find one? I've definitely tried to Google for it but the phrases I'm using are long and not producing the right results. I obviously don't know the correct term(s) to search for.
If I knew a bit more about circuitry in general and the USB standard specifically, I could probably solder together a cable like this with a couple diodes to prevent the charger from zapping the motherboard's USB, or perhaps, as mentioned, not connect the power wires at all. I do have 6-8 spare cables laying around but I'd rather not start chopping and black-taping unless I get some confirmation Plus I only have one female end to mangle, so... yeah ;p
My idea for the splice & solder (in case no commercially available alternative exists):
Code:
computer - 2 data -----\
|----------------- device
charger - 2 power -----/
Most chargers and phones have some kind of regulator circuit built-in anyway, at least that's the impression I'm under. Generally if you crack open a charger there are only two cables black and red (+/-) which makes things considerably easier but that's assuming you have a charger that's just for charging and not one that requires you already have a usb cable to plug into it (like some that come with phones now). Standard wiring color schemes applied to all the cables I've cut open and spliced so as long as you go black/black red/red from the charger and leave the other wires untouched you should be ok. You'll know if something's wrong quickly because your phone will get quite a bit hotter than normal and do so faster, and you shouldn't need to add any components as they're already in the charger circuit (diodes to prevent current flow-back, resistors and the transformer to convert to dc, capacitors to smooth the current, etc). Just use common sense when working with this, don't solder until you test, don't splice wires together that don't seem right, use a multimeter to make sure you're getting the proper wires, don't work on anything while it's live unless you're properly insulated and even then not if you can help it, all that jazz.
Yeah, my biggest concern would be that I was told that some USB devices negotiate current requirements with the motherboard, which I'd assume goes over the two data wires, but I remember landline phones have 2 wires but both power and data flow over it, so I wasn't completely confident that the two power wires weren't passing data as well. If I run the 2 data to the computer and the 2 power to the charger, and it turns out that the negotiation requires all 4 wires be connected from the device to the computer, then I've just ruined two good cables.
I just am not so super confident in my logic and theorizing that I'd want to risk frying circuitry If I can nab a commercially available accessory that does this for $30 it's a lot less than having to buy another $700 device and a new $200 motherboard (at the least)
I don't think you really have to worry, but I wouldn't replace the charger wires, I'd connect the wires from the charger to the power lines inside the usb cable that way even when the charger isn't plugged in the phone is still getting some power and it'd basically be hooking them up in parallel when the usb and charger are plugged in. You could always go buy a $20/$30 cheapo phone that connects through microusb-to-usb and test the cable on that through a USB hub. that way if something goes wrong you're only losing a cheapo phone and a usb hub, but honestly things shouldn't fry as long as you get the wiring right and don't try to do something like black to red because then you're feeding power from the charger back into the usb socket which is where things get ugly.
I think i've found something on the interwebs, that will actually save you the wire-splicing and soldering
It is actually just what you described, it uses 2 USB ports in order to provide 1000mA to a device.
dealextreme.com/p/cable-style-dual-power-1000ma-usb-2-0-4-port-hub-13526
Sorry for the inconvience with the url, atm i'm not yet allowed to post links directly... :/
Xadro said:
I think i've found something on the interwebs, that will actually save you the wire-splicing and soldering
It is actually just what you described, it uses 2 USB ports in order to provide 1000mA to a device.
dealextreme.com/p/cable-style-dual-power-1000ma-usb-2-0-4-port-hub-13526
Sorry for the inconvience with the url, atm i'm not yet allowed to post links directly... :/
Click to expand...
Click to collapse
I know that some of the smaller usb external drives have a cable that has 2 "type-a" connectorsto allow data connection/enough power for the drive. I have not seen these in micro-usb form, only mini-usb. SO, I do not see why it would not work.
papabear said:
I know that some of the smaller usb external drives have a cable that has 2 "type-a" connectorsto allow data connection/enough power for the drive. I have not seen these in micro-usb form, only mini-usb. SO, I do not see why it would not work.
Click to expand...
Click to collapse
Agreed, USB offers about 2.5v of charge aswell as data connectivity of course, I don't understand why it wouldn't work... I can tell you from experence through that it does take about 40% longer, and will suck the life out of a laptop if you are using it on battery mode.
The reason I was thinking about cutting the power wires from the computer entirely is I don't know what dumping 1-2 amps into the computer's USB port is going to do ;p
Edit: Looks like newegg.com/Product/Product.aspx?Item=N82E16817707145&cm_re=2a_output_usb-_-17-707-145-_-Product should do what I'm interested in, if the details are legitimate. Who knew finding a hub with full details would be so hard? ><
LycaonX said:
The reason I was thinking about cutting the power wires from the computer entirely is I don't know what dumping 1-2 amps into the computer's USB port is going to do ;p
Edit: Looks like newegg.com/Product/Product.aspx?Item=N82E16817707145&cm_re=2a_output_usb-_-17-707-145-_-Product should do what I'm interested in, if the details are legitimate. Who knew finding a hub with full details would be so hard? ><
Click to expand...
Click to collapse
just as papabear already said, there are also external hdd, that use this kind of wire.. so it should be no problem. If the ports arent't capable of delivering that power (but as far as i know they are designed for 500mA each), simply you will not get the the full 1 A.
And i must agree, hardware vendors rarely add detailed power info -.-
Related
Hi there,
some might know it some might not..
the Datakacabels can only charge the HTC Desire with 500mA (this will result in a Navigation System that DRAIN the Accu DOWN while charging...)
therefor you need the Special Vehicel Cable+Caradapter from HTC the cabel has some settings changed so it can actualy work as a AC adapter with 1000mA
can someone explain how to build your own AC cable with a Usal cable?
sorry for my bad english thou...
found the answer myself http://www.abload.de/image.php?img=usb_male_plug_type_a42xe.jpg connect both together or use Isolating tape on both
It should be the charger NOT the cable that has the data pins shorted. If you use a modified cable on a computer it will draw more than the 500 mA and you risk causing damage as this is out of specification for a USB port.
daverave999 said:
It should be the charger NOT the cable that has the data pins shorted. If you use a modified cable on a computer it will draw more than the 500 mA and you risk causing damage as this is out of specification for a USB port.
Click to expand...
Click to collapse
If USB tries to draw more than 500 mA then the USB standard has an overload protect so the PC should shut the USB port down (and present a notification via Windows) so you should not be able to overload but trust me, having to reset the USB port is a pain so best avoided anyway.
I'm curious as to how a device can draw more current than is being supplied to it? This isn't how it worked last I looked.
alias_neo said:
I'm curious as to how a device can draw more current than is being supplied to it? This isn't how it worked last I looked.
Click to expand...
Click to collapse
Good point. Perhaps the port is capable of supplying more? Maybe the power is supplied across multiple ports so if only one port is in use, more can be drawn?
But non the less, overload protection is there and functions.
I'm curious as to how a device can draw more current than is being supplied to it? This isn't how it worked last I looked.
Click to expand...
Click to collapse
Good point. Perhaps the port is capable of supplying more? Maybe the power is supplied across multiple ports so if only one port is in use, more can be drawn?
But non the less, overload protection is there and functions.
Click to expand...
Click to collapse
Most hubs or headers should be capable of supplying more. The 500mA limit is a specification of the standard and that is only in desktops and like. Less is possible as most of us have experienced. It wouldn't be too difficult to make a usb charger capable of 1A.
Iv searched high and low however for a ready made one from a third party. Unless its made by one of the big phone makers or similar you'll probably not find one and I settled for a 700mA one.
That said, charging slower is of course better for your battery.
EDIT: also, as mentioned, you would modify the charger not the cable. If the charger has no data pins it can't cause a problem. For PC charging you could make a fork cable.
-------------------------------------
Alias::NeO on HTC Desire
Ive had a simple idea of how to make a charger that can be left plugged in but once the phone is removed the charger disconnects from the mains until the phone is reconnected.
i would like the idea to be open to all manufactures to use for free as i think it would help the environment anybody got any ideas how to proceed maybe offer it to google?
Not sure what you mean by disconnects from the mains. Are you saying that it will not use any power?
I do not understand your idea, you can explain better?
If you leave a charger plugged into the mains with no phone connected, it still uses electricity which is a waste.
The OP's idea would be to have the charger break the mains circuit when a phone is not connected.
Sensible idea.
Off the top of my head, with an old transformer model, you'd have a mosfet to close the mains circuit when the 5v circuit is closed. To start it off you'd have a push to make switch in parellel to the mosfet.
So you connect the phone, push the start button, the mains circuit is completed energising the 5v circuit which activates the mosfet keeping the mains side closed.
When you disconnect the phone the 5v circuit is broken, the mosfet opens the mains side and power is totally cut.
Not opened a recent charger though but given their size I don't think they work like an old chunky transformer type.
This is done on several larger devices, all you are doing is creating a loop that recognizes load or no load, when no load is on, the shunt (elec gate) is in the open position, when it has load it creates a closed position allowing power to pass through. My guess is the cost verses benefit is not there to implement yet on such small elec demand devices. FYI even a plugged in extension cord will draw a micro amount of power, so the Zero use when not plugged in would not happen, but near zero is doable.
Good thinking on this........
I just switch the socket off
xaccers said:
I just switch the socket off
Click to expand...
Click to collapse
lol probrobly the simplest, easiest and best solution
My idea would be to have a small magnet on the back of the device to pull a relay in this would be isolated from the mains but act directly on the power circuit without additional power.
or make a flexible ferrite core not dissimilar to those rubber magnets to a cable and add it to a usb cable and do much the same thing.
Anyone wanting to know how to fast charge using the usb port on your pc/laptop?
This usually takes ages compared to charging via mains lead, the hack itself is quite simple and involves modifying the usb cable
my results are as follows (these can vary depending on what you are using your phone for, what background apps running, etc.
charging with mains lead :
4.2v
998mah
mains ac
charging with STANDARD usb lead:
422mah
3.999v
standard usb
and finally the MODIFIED usb lead hack:
4.161v
782mah
usb hack
as you can see it is a 53% increase in charging compared to standard usb charging mah, and slightly under mains ac charging mah,
as my phone is always plugged in at my work pc or home pc or laptop or whatever this works out good
TUT:
use at your own risk this is for information purposes only and I hold no responsibility to any damage that may arise
using a micro usb cable (charging cable for htc phones)
cut it using a pliers half way through the cable
using pliers again cut away the thick black wiring, the red and black small wiring, and white and green wiring
from the usb port end to the microusb connect the black and red cables together so they join
from the microusb end short out the white and green cables together
from the usb port end leave the white and green cables, do not touch these
use insulation tape/solder to clean it up and then your cable is ready
I will make a mod for car chargers also soon
see attached image showing which wires to cut and which to join up and which to leave alone, if this helped you in anyway (it should help you ) then please hit the thanks button
this mod will trick your pc/laptop/htc into thinking that it is not a pc usb cable and will allow higher currents and voltage to your phone
you can check this with current widget from market place
once this mod is done, you cannot use the same cable again for pc/usb tethering or usb disk drive, only cable can be used for charging
Care to explain how you did it? I got a spare Micro USB cable willing to try and make a tutorial with pictures.
So you forgot to put the directions for the mod...
Sent from my Sensation 4g using XDA App
directions are up with a picture
Seems awesome, but I'd be way too scared to try that on my own. >.<
First of all im not against this mod. Just want to share my experience just this morning.
I charge my phone via the stock usb cable to my pc and leave until morning approx 7hrs. What happen now my phone Menu button become unresponsive tried different method, shake google for answer , but nothing work. Worst come to worse i may return the phone to HTC for repair. So for anyone want to try this be careful, this could be a problem with HTC as it could result more problem.
HTH
Sounds dangerous and a bit risky. Why not just use a USB y cable and a micro USB adapter?
http://item.mobileweb.ebay.com.au/viewitem?itemId=370586078337
Its not dangerous nor risky in my opinion...
I am using this trick since I owned HTC TYTN2 and I`m using it now.
Hmmm...
I always thought the different voltages came from the charging adaptor..
The phone adaptors have normal charging voltages so thats why charge normal speed... however PCs have lesser voltage due to USB ports. I think the PC voltage varies on the device that's plugged in.
Thus, we can use the same cable for charging with an adaptor and also for data transfer and the phone knows what its plugged into.
Pardon me if i'm wrong... could be a misconception i had
Why go to that bother when you can just plug in the adaptor!
Sent from my Sensation using Tapatalk
thunderskain said:
Hmmm...
I always thought the different voltages came from the charging adaptor..
The phone adaptors have normal charging voltages so thats why charge normal speed... however PCs have lesser voltage due to USB ports. I think the PC voltage varies on the device that's plugged in.
Thus, we can use the same cable for charging with an adaptor and also for data transfer and the phone knows what its plugged into.
Pardon me if i'm wrong... could be a misconception i had
Click to expand...
Click to collapse
It's got nothing to do with the voltages, they are the same. The phone senses that the data wires are not connected together (open) and presumes that it is plugged into a pc / laptop usb port. Because of this the phone then restricts the current it draws from it's source so that it doesn't cause damage to the pc / laptop usb power supply.
Inside the phone charger the data connections will be shorted out so the phone knows it's the charger and can draw full current.
There is a chance that it could damage the pc / laptop if the usb port supply is not rated high enough
Just to update the thread, I've been using this for the last year and a half on all the HTC's I own and no issue at all,
I can connect my phone to my laptop if i dont have access to mains
I can use the cable in the car to a usb charger (which charge slow for some reason)
there are many reasons i.e. in work where I can only use a usb port and no extra plugs for a/c, it means I don't have to carry a plug around with me just a usb cable,
A good post, the issues around drawing to much power could effect older laptops
If I understand correctlly USB3 has the ability to supply more power than USB 2
Anyone any idea if this would reduce charge times without the mod?
battery will die soon enough...
you should place a 220 Ohm resistor between the data lines (green and white) if you do that, you will be able to use the where it was intended for, data
with the 200~220 Ohm resistor the phone recognizes the connection as AC-charger. i dit this with a DealExtreme carcharger
source: http://www.ifixit.com/Guide/Upgradi...-current-to-HTC-Hero-and-other-devices/5172/1
If you can get to the ID-pin of the USB-connector (pin4) and connect the following resistors to GND, you get interesting USB modes
Dock-mode = 44-49 kOhms
Car-dock = 5-16 kOhms
source: http://forum.xda-developers.com/showthread.php?t=1185431
I've done this, and soldered all the cables in the right positions, now I'm testing the charge times between this and a normal usb cable on my HTC G1.
First thing I noticed was that my phone says charging via AC, instead of usb.
Will edit this with the results.
Edit : Been a while, forgot about this, so I forget the exact numbers, but my phone charged around 1 and half hours faster with this mod, and yes, it was on USB 3.0 so its quite good.
Worthless to try if you don't have USB 3.0.
Sent from my GT-I9100 using xda premium
Does this mod increase charge with main AC lead that output 2A e.g. Ipad charger head???
usb3 provides up to 900ma
so usb3 should work without any problems
this is usb specification
http://www.usr.com/education/peripherals0.asp
by default usb2 provides 500ma unless it is asked for more by the device, this is where the mod of the cable comes into play, it provides up to 1000ma with this mod
johnerz said:
If I understand correctlly USB3 has the ability to supply more power than USB 2
Anyone any idea if this would reduce charge times without the mod?
Click to expand...
Click to collapse
I have an Notebook with USB3.0 and also Power-USB. (Power usb only works with a dockingstation).
The charging is also bad. Takes about ~4 hours from 2% - 100%.
I thought about power reducement by phone, when dataconnection is available. Now I know it for sure :-/
OK so I need help clearing up some things about charging my phone. I have searched forums and google and I keep finding conflicting responses. I figured XDA may have plenty of knowledgeable people to clear things up. Here is what I think is correct. Please correct me if I'm wrong. I want to find a faster way to charge my phone.
USB data cables (with the exception of some that come from our phone manufacturers) are limited to 500mA because the data pins limit the current that goes through regardless of the rating of the wall adapter.
Example: you have a 1A AC adapter but your phone is only drawing 500mA when charging because you are using a data cable.
Charging cables have the data pins shorted (or missing) and will charge your phone at whatever mA the AC (or DC) adapter is rated at.
Your phone will also have a built in regulator to draw a certain amount of mA's regardless of what the adapter/cable are rated at.
Keeping all these things in mind, I have an AC adapter rated at 5V (standard for these phones) and 2.1A (2100 mA), and my factory samsung micro usb cable that is capable of data transfer as well. Since it is used for data transfer as well I wanted to buy a charging usb cable (with the data pins missing). My theory is this will remove all bottlenecks for charging speed and let the phone's battery pull what it needs, uninhibited by the usb cable and with more than enough current to keep a fast charging rate even when the phone is being used (light usage of course, I dont want to overheat the battery).
If anyone knows about this please clear things up for me, this would make it so much less inconvenient to give my phone a quick charge when needed.
This is my understanding, i might be incorrect:
The 500mA limit doesn't come from the cable but from the mainboard usb specifications.
USB2 can deliver upto 500mA, USB3 upto 900mA.
The different between the "charging" and "data" cables are most likely missing pines, but this has no influence on the current delivered via the cable.
I believe the phones uses the missing connections on a "charge" cable to detect it as charging from an outlet instead of a computer.
I would find it interesting to know if the phones charging routines differ depending on which power source, it thinks, it is connected to.
Probably some typos, but i'm tired ;-).
I guess only thing left to do is buy the usb cable without the data pins and see if it makes a difference. I'll post the results here.
Sent from my rooted GameBoy Color
As Dark3n stated, the limitation is with the USB port capabilities.
Ok you said you want to know the fastest way to charge. The fastest is with the phone off of couse. 2nd. Having a phone in airplane mode will charge fast.
Sent From Space Using My ICS Flavored Sensation
Ohh ok took a while to understand what he meant. Makes sense, thanks all this clears it up
Sent from my rooted GameBoy Color
The fastest method is to have a second battery and an external charger. A battery is much more portable than a charger if you are just out for a day, and if you are traveling, the extra battery & it's charger are not much more bulk than the phone charger alone. I go this route whenever possible as the benefits are inestimable.
Hi everyone... I have an asus tf700t and I was wondering if I can charge it using the belkin mini surge protector with usb charger ( w**.belkin.com/us/p/P-BZ103050-TVL )? I just wanna make sure if it would be ok plugging the usb cord straight to the usb socket of this belkin usb socket. I carry a lot of gadgets with me whereever I go so I kinda feel that it would be bulky carryng a lot of chargers for my cellphone, laptop... etc. Would this be safe? I just experienced last week someone's charger got toasted using a public wall socket using the original charger. Thats why I thought of buying a surge protector as well. Thank you.
Depends on what you mean. Do you mean skip the Asus wall plug and use the usb ports on this protector? Then the answer is no. The usb ports on any device you use to charge the tablet needs to be usb 3.0 and supply the needed 15v of power. All of the usb plugs that are sold are made for 2-5v devices. If there is one that does supply the 15v then I have not seen it and many people using this forum would probably love to purchase it. You've stated one main reason to buy something like this, limiting the number of plugs to carry around, but it's also like $40 bucks to buy another plug from Asus.
That 2-5v is enough to charge cell phones, gps units, apple products, other tablets that don't use a proprietary power plug, etc. It may supply a small trickle of power similar to hooking up the device to a computer while the tablet is powered off. That would take hours to charge the device and not what you are looking for. I think one of the advantages Asus went for in using usb 3.0 and 15v is the speed of which the device can charge. It is pulling more power and able to delivery it to the battery faster. That is my guess but it is limiting our after market choices.
Now if you mean use that as added protection and have the Asus plug plugged into it, then yes it will work. If you are concerned about pulling too much power through it then don't have the device hooked up to it and use all of the other ports on the protector at the same time. That little device does seem neat. I lost an a/c adapter for my laptop when lightening struck really close to my hotel. Fried the power brick but luckily the laptop was not damaged. At work and at home I use a power strip/surge protector when plugging in the tablet to charge.
fsured said:
Depends on what you mean. Do you mean skip the Asus wall plug and use the usb ports on this protector? Then the answer is no. The usb ports on any device you use to charge the tablet needs to be usb 3.0 and supply the needed 15v of power. All of the usb plugs that are sold are made for 2-5v devices. If there is one that does supply the 15v then I have not seen it and many people using this forum would probably love to purchase it. You've stated one main reason to buy something like this, limiting the number of plugs to carry around, but it's also like $40 bucks to buy another plug from Asus.
That 2-5v is enough to charge cell phones, gps units, apple products, other tablets that don't use a proprietary power plug, etc. It may supply a small trickle of power similar to hooking up the device to a computer while the tablet is powered off. That would take hours to charge the device and not what you are looking for. I think one of the advantages Asus went for in using usb 3.0 and 15v is the speed of which the device can charge. It is pulling more power and able to delivery it to the battery faster. That is my guess but it is limiting our after market choices.
Now if you mean use that as added protection and have the Asus plug plugged into it, then yes it will work. If you are concerned about pulling too much power through it then don't have the device hooked up to it and use all of the other ports on the protector at the same time. That little device does seem neat. I lost an a/c adapter for my laptop when lightening struck really close to my hotel. Fried the power brick but luckily the laptop was not damaged. At work and at home I use a power strip/surge protector when plugging in the tablet to charge.
Click to expand...
Click to collapse
Ok tnx for the input. Just wanted to be sure if it would not harm the device if I use the usb wire without the charger adapter that came with asus but rather plug the usb cable directly to the belkin usb socket. Being stated that the tf700t is usb 3 and 15v is needed, will the belkin suffice to charge the device using its usb slot for charging without causing any harm? The spec says in belkin mini surge protector is 5V/500mA each usb port.
MasterYodaMD said:
Being stated that the tf700t is usb 3 and 15v is needed, will the belkin suffice to charge the device using its usb slot for charging without causing any harm? The spec says in belkin mini surge protector is 5V/500mA each usb port.
Click to expand...
Click to collapse
It should work and do no harm, but it will be very very slow - maybe 5% per hour...
fsured said:
Depends on what you mean. Do you mean skip the Asus wall plug and use the usb ports on this protector? Then the answer is no. The usb ports on any device you use to charge the tablet needs to be usb 3.0 and supply the needed 15v of power. All of the usb plugs that are sold are made for 2-5v devices. If there is one that does supply the 15v then I have not seen it and many people using this forum would probably love to purchase it. You've stated one main reason to buy something like this, limiting the number of plugs to carry around, but it's also like $40 bucks to buy another plug from Asus.
That 2-5v is enough to charge cell phones, gps units, apple products, other tablets that don't use a proprietary power plug, etc. It may supply a small trickle of power similar to hooking up the device to a computer while the tablet is powered off. That would take hours to charge the device and not what you are looking for. I think one of the advantages Asus went for in using usb 3.0 and 15v is the speed of which the device can charge. It is pulling more power and able to delivery it to the battery faster. That is my guess but it is limiting our after market choices.
Now if you mean use that as added protection and have the Asus plug plugged into it, then yes it will work. If you are concerned about pulling too much power through it then don't have the device hooked up to it and use all of the other ports on the protector at the same time. That little device does seem neat. I lost an a/c adapter for my laptop when lightening struck really close to my hotel. Fried the power brick but luckily the laptop was not damaged. At work and at home I use a power strip/surge protector when plugging in the tablet to charge.
Click to expand...
Click to collapse
One correction please. Its not usb 3.0. Its just usb 2.0. Check for the specs on asus site.
king231 said:
One correction please. Its not usb 3.0. Its just usb 2.0. Check for the specs on asus site.
Click to expand...
Click to collapse
It's a USB 3 plug, and the additional lines are somehow used by the Asus charger for detecting the tablet and switching the voltage.
_that said:
It's a USB 3 plug, and the additional lines are somehow used by the Asus charger for detecting the tablet and switching the voltage.
Click to expand...
Click to collapse
Oh! I was talking about the tablet. If the tablet had USB 2.0 why would the plug be of USB 3.0.