Voltage for the Usb

[BALLARI]

Hello , i want to know what is the Voltage supplied to the usb devices in the computer , my usb devices seem to be giving problems like sometimes they are not detected , sometimes data transfer is slow , cna you tell me what is the minimum voltage require for the usb , please help me thanks in advance

[Sam.D]

A USB drive (USB key in English) is a removable storage device for small format that can be plugged into the USB port of a computer. The Universal Serial Bus is a high-speed connection that allows you to connect devices to an external computer (host in the USB terminology ). It enables simultaneous connection of 127 devices per controller (host). The bus allows connections and disconnections in hot (Hot-Plug, no need to restart the computer) and provides the power device under 5 V in the limit of 500 mA.

[ThoMas321]

Power usage for USB 3.0

• Bus-powered hubs: Draw Max 100 mA at power up and 500 mA normally.
• Self-powered hubs: Draw Max 100 mA, must supply 500 mA to each port.
• Low power, bus-powered functions: Draw Max 100 mA.
• High power, bus-powered functions: Self-powered hubs: Draw Max 100 mA, must supply 500 mA to each port.
• Self-powered functions: Draw Max 100 mA.
• Suspended device: Max 0.5 mA

[RoninBlade]

The USB bus can supply power devices, to a certain limit current consumption (500 mA). This is particularly used to allow charging of mobile devices, which are emerging adapters sector with a USB connection limited to the power supply. The USB connector has a certain spread beyond computer peripherals strictly as electrical connector of low power. Normally 5v but we can't be sure because it also depends on the setting of this USB bus. For example, if you have external hard disk that you could connect to your computer via USB. It might work on your computer as long as the voltage meets the require voltage of your external hard disk but when you try it on some other computers it might not work.