The Output voltage from an USB port is 5v, and it can't be changed, isn't it?!
But what is the maximum amperage that I can drain from a smartphone? It depends on the battery, hardware or is limited by the OS? There is difference between Android/iPhone/otherOS phones? Can I control the output amperage with an App? And if the phone is rooted?
Important example what is the maximum amount of current that can provide Iphone 6 from USB?
The official maximum on current provided on USB 2 OTG port is 500mA and minimum is 8mA when the port is in Host mode.
Source http://www.usb.org/developers/onthego/otg1_0.pdf #2.5
The USB 2.0 specification allows the voltage output from a USB port to be anywhere between 4.40 V and 5.25 V, but it is typically 5 V.
While you could construct a USB port that has a different voltage, you should probably not do that because a normal USB device you plug into that port could malfunction or be damaged. It's unlikely that your phone provides a feature for changing the voltage of your USB port.
The USB specification allows devices to draw 100 mA from a USB port before they have reached the "configured" state (see Chapter 9 of the USB specification for more information about USB device states). Once the device is configured, it can draw more current, as long as it doesn't exceed the amount of current specified in its configuration descriptor.
If your phone does not get the device into the configured state by default, it might be possible to write an app to do it, thus allowing your device to draw more than 100 mA without violating the USB specification.
Not sure what you're trying to achieve...
An iPhone 6 can provide some (limited) power to devices plugged into its lightning port (it doesn't have a USB port).
There are cables that connect the phone to a host computer (or charger) over USB, but you're not going to get power out of the phone that way (only power into the phone).
A lightning connector uses active electronics inside the connector's cable to get the phone to assign functions to the different pins. Moreover there's authentication involved, preventing you from making anything yourself for it without apple's involvement. You'd need to join the MFi program to get the needed documentation. There's an NDA involved, and Apple is notorious about such things, so you're unlikely to find much reliable and/or verifiable info on the Lightning conector till you join the program.
See also here.
A list of USB standards and their voltage/current ratings is shown on wikipedia
The Nexus 5X and 6P seem to be the first phones to support power delivery via USB Type C connection: Link However there is conflicting information on how well this is implemented.
Your goal of a 3A output current seems to be possible with USB-PD, but it would appear that no smartphones are currently supporting this.
Important example what is the maximum amount of current that can provide Iphone 6 from USB?
An iPhone with a Camera Connection Kit will limit you to 100 mA. If you connect a device that claims more than this in its descriptors, or tries to draw more than this, it will get cut off with an error:
As reported by this iPhone 6 and 6 plus may be able to supply a current of about 1 Ampere at the voltage at which they get charged. Though I can't be very sure about it unless the specification of the USB drive used are provided.
3A of currents seems to be way too much. If it would have been possible, they could have used it to charge mobile phones faster (I don't know if they do use 3A chargers or not, but this can be seen on their charger at the output tag ).
I would have not done such an experiment until and unless I was very sure about it.
Disclaimer : What ever experiment you do, you it do at your own risk. In the above answer I have just tried to explain what I would have done and have provided reason to back that.
Amperage drained from the power supply is proportional to these factors:
1- The net device's impedance(including battery and other feeder circuits).
2- Device's internal current limiter.
3- Power supply's maximum current limitation.
power supplies usually provide less amperage than it is dictated by the device. If they provide more of, their constant voltage, i.e. 5V, drops below its standard. Therefore, the limitation is posed by the supplies in the first place. Devices, provide you with another current limiter to lower the risk of using failure of nonstandard power supplies. I'm not sure whether you can change the maximum threshold of internal current delimiter to drain more power or not, but I'm sure you can not change it in your power supply.
© 2022 - 2024 — McMap. All rights reserved.
