Portable externally powered USB hub with power bank or other high powered USB hosts for working with self powered external hard disks and other power hungry devices OTG

Update: Sorry, Images were lost during a recent update. Will be fixed soon.

With the advancements in technology we are now capable of working everywhere with the help of smart phones and tablets. One technology that’s powering productivity is the On The Go (OTG). One can connect any USB peripheral through OTG cable to mobiles or tablets and use it.

One major problem with OTG is is cannot serve the high power requirements of peripherals like external hard disks that are self powered and in my case 3G USB Dongle. When we can only connect and work with flash drives how can we call it OTG?

I faced this problem with my Venue 8 Pro that was unable to power my USB dongle to connect to the internet on the go. In search of a solution I was finally able to create a USB Hub that could work with high powered devices on the go without any power requirement from the Host(Tablet, In my case).

USB hub powered by laptop.

The above image is the final working sample of the solution. The USB hub is powered by laptop and host is my tablet. It was able to handle all the peripherals connected.

1. Mouse

2. USB 3G Dongle

3. Lenovo S850 Mobile

4. Power bank (Just connected to check if it could charge or not)

I haven’t tested this version with Power bank yet because it didn’t have enough charge.

How it works?

Here is how it is designed and how it works. The figure below is the actual USB Hub that’s  designed. The USB cable in black is the power source for the hub which should be connected to power banks, laptops, car chargers or any other USB powering machine.

The white cable is to be connected to the host (Tablet in my case).

OTG image 2

The actual schematic

Schematic of USB hub self powered.

In the figure it is clear that data lines are not disturbed but just the power terminals are altered. GND of both the USB ports are shorted.

VCC from the host is disconnected and VCC from the power source is connected to the HUB.

Simple connections with great output.

Hope you liked it. Comments are always welcomed.

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