How to Add Separate USB Power Supply to an External Hard Drive

Intro: How to Add Separate USB Power Supply to an External Hard Drive

Hi guys, in this video we will see how to make a Y splitter cable that divides the 5V power supply of, for example, an external Hard Disk and the data.

Have you ever installed a heavy game on an external hard drive?

If yes, you know that when the game requires too much data from the hard disk, it disconnects.

The Hard Disk disconnects because the current required for all that data is too much compared to what the motherboard can supply and therefore, for a fraction of a second, the Hard Disk disconnects.

Thanks to the cable that we will make in this video, this won't happen again because the current required by the Hard Disk will come from another USB socket that we can connect to a wall adapter or any external power supply.

STEP 1: Prepare the Power Cable

First of all, you will have to provide yourself with a normal USB that you do not need or that is broken or cut.

Once you have found the cable, if it is intact, you will have to cut and strip it to detect inside (if it is a standard USB cable) four colored wires of the following colours: White, Green, Red and Black.

Of these four wires, the only ones you will need are those carrying the negative (therefore the GND) and the positive (therefore the 5V). These are the Red and Black threads (as it was easy to guess). You can then take a pair of scissors and cut the Green and White threads (so you can wash them afterward).

Once this is done, you have to check that the cable works correctly and that there is voltage at the ends of the red and black cables.

You can connect the cable to the computer and measure the voltage, but I don't recommend it (because you could damage the computer if you short-circuit). Rather, take a phone charger and insert the USB into it (which surely is protected from short circuit and surely would be damaged less than a computer and certainly less expensive than a computer).

Once the USB socket is connected to the charger, insert it into the socket and, with a digital multimeter, measure the voltage across the Red and Black wires. The value should be around 5V (in this case, 4.99 )

STEP 2: Strip the Main Wire

It's time to move on to the other cable, the main one, the one that will be connected to the Hard disk or I don't know what.

You will have to peel the latter using a very sharp cutter and in this position. You will need to apply a little pressure, at a small angle, on the cable jacket and sooner or later you will start to feel that you are cutting through the jacket.

When you start to feel something harder, stop, you've reached the metal mesh (which protects the wires from interference).

Repeat this process on multiple sides of the cable so you don't have to strip the jacket.

When that small portion of cable is totally free from the sheath, cut the metal mesh with a pair of scissors and then cut the last layer of protection from interference, made from a thin sheet of metal.

STEP 3: Locate the Positive and Negative on the Main Cable

At this point, as with the cable above, we need to locate the red (positive) wire and the black (negative) wire inside the cable.

To these then, we will have to weld in parallel the red and black wires previously identified in the other cable, the power supply one.

STEP 4: Strip the Power Wires Without Cutting Them

What we have to do now, in fact, is to try to strip the red and black wires of the main cable, without cutting them. For this, I first of all interleaved a piece of metal tape between the affected wire and the others, so that I didn't risk cutting the others unintentionally.

At this point, as we did before, we now have to pass the blade of the cutter over the red wire in order to slowly detect the copper underneath.

by doing so, we will be able to bare the copper of the wire without cutting it. The result should be something like this

STEP 5: Do the Previous Operation Also for the Black Wire

Well, stripped the red wire, we just have to do the same thing with the black wire. This time I put my finger in place of the piece of metal. mmhh...for the record, I still have the finger. Again, the result should be something like this

STEP 6: Prepare the Wires for Soldering

Good. At this point, we just have to prepare the wires for welding.

To do this, I take the red and black wires of the power cable and cut them just three millimeters, just enough for a drop of tin.

Once this is done, with the tip of the soldering iron, wet the wires with tin so that later it will be easier to solder them to the wires of the main cable.

STEP 7: Solder the Negative Wires Together

Good. At this point, there is nothing left to do but wet the black wire of the main cable with a drop of tin and, subsequently, take the black wire of the power cable and solder it together with the black wire of the main cable.

The result should be something like this (photo)

Next, it is important that you insulate this weld with plenty of electrical tape.

STEP 8: Do the Same for the Red Thread

Once this operation has been carried out for the two black wires, you will have to repeat it for the black wires. This therefore includes: soldering the red wire of the main cable, soldering the two red wires together and insulating the latter with electrical tape.

STEP 9: Stretch the Heat Shrink Tubing

Since we have not cut the main cable but we have only stripped the wires a little bit inside, to insert a heat-shrinking sheath on the cable, we have to find a way to pass it through the USB connector which, through which, as you can see, does not pass.

Fortunately, two things come to our rescue: the elasticity of these sheaths and a thick caliper. With this, all we have to do is insert its tips inside the sheath and widen them in order to widen the sheath.

Once this is done, as if by magic, the sheath will enter the USB connector.

STEP 10: Reinforce the Notch

Once the sheath has widened, insert it inside the cable and then cover the notch with a piece of duct tape (or American tape) with which we wrap the entire stripped part of the cable. This tape, being very strong, will give stiffness to the welds.

STEP 11: Let's Cover the Carving

Good. Now we insert the sheath inserted before over the welds and over the duct tape.

Once this is done, we shrink the sheath with a lighter and, when the sheath is still hot, we press on it while rolling it on the table. This operation will help the sheath take the shape of the cable.

STEP 12: Test

Once you've isolated everything, it's time to test that everything works. In theory, you'll need to connect one end of the main cable to your computer and the other end to a 5V supply which in my case, came from a phone charger.

The computer should read the hard disk smoothly and without errors. If we try to disconnect the Hard Disk From the computer, the Hard Disk should stay on (and in this case, a white light will shine on it)

STEP 13: Finished

well, now you can go back to playing your game on the external hard drive, requesting a lot of data, without risking the hard drive shutting down because it draws too much current. See you in the next video!

Comments

[Aerospaceman]

I'm not familiar with 3D printers yet, but the presentation you have is both interesting and well written especially a weather station. Thank You.

[Maurizio Miscio]

Thank you very much but i can't get why you mentioned the 3d printing and the weather station

[RaymondR6]

I am worried about this step:
"Once this is done, we shrink the sheath with a lighter and, when the sheath is still hot, we press on it while rolling it on the table. "

Instead of a lighter, use a heat gun or a hot hair dryer. The lighter flame is difficult to control, and you can accidentally burn the heat shrink tubing or sheath. Use a source of hot air.

[Maurizio Miscio]

You are absolutely right man. Unfortunately i never had the chance to buy an hot air gun so i usually use the lighter instead of it (i'm poor)

[beentheredidntdothat]

12/14/2022
Thank you for this. It is well within my abilities and the best part is no 3D Printer is involved. I'm a retired senior and I will NOT be purchasing a 3D Printer ever. I do currently own a razor knife, a soldering iron with paste and solder, heat shrink tube, hot air blower, multimeter, protected power-strip, extra Samsung high-speed USB charger, extra USB cable, functioning brain connected to so-so vision and everything else necessary to complete this project. Right now I have absolutely no need for this cable splitter but will make it anyway just so the memory of it fixes in my noggin. Sort of like muscle memory. That way if and when I really need it I can roll my eyes back up and into the fog that is my memory. Hopefully what pops up will be an "Oh yea, I remember doing that!" One other thing, I have a portable USB hard drive that works great connected the way it is but will use the splitter anyway.
Again, thanks for this for real.

[Maurizio Miscio]

Thank you very much. If this is your passion or part of what you like to do in your life, DO IT and do not think that you are not YOUNG enough to do something you like or SMART enough. Everybody is. I can't get why you describe yourself in this way. And, listen to me... you will be in love with 3D printing when you will buy one, i promise (cause you have to get one, is so smart to have one)

[MerlinTheGreat]

Nice project.
I am worried though about your computer's usb port(s) with this modification.
It would be better to add a diode to the positive wire coming from the computer and from the auxiliary power supply, so that the current can only flow from the computer and the extra power supply to the device and not from the power supply to the computer and vise versa.
These diodes will protect both your computer and the extra power supply.

[MarkK71]

granted you would always have to use an external supply but would it be better to cut the red and black from the computer and just connect the external supply?

[Maurizio Miscio]

i replied to your question in the first comment of this discussion

[MerlinTheGreat]

Cutting the red and black wires could be done, but then you would always have to use the external power supply since the computer's usb power is no more available.
With the diodes you could use either the computer's usb power OR the external power. In that case, if connected, the external power supply would become the main power provider and take over from the computer.

Another solution would be to make a piggy-back cable. This would be a solution one can use with all devices (disk drives, usb hubs,...), not just with one device.
You would need one female usb connector, and two male usb connectors with cable attached to them.
Connect the data lines from one male connector to the data lines from the female connector and label the male connector 'PC'.
Connect the power lines from the second male usb connector and connect them to the power lines of the female connector and label the male connector 'POWER'.
Make sure to insulate the wires properly.
Now you can use the original cable from the device to directly connect the device to the PC, OR you can put the piggy-back cable in between the original cable and the PC and connect the power cable to a usb power supply to have more power available for the device.

[Maurizio Miscio]

i thought about using a diode on this project to prevent the pc to revice the 5 volts of the power supply but there are no reasons. The problem with this configuration is the fact that i infact use this kind of splitter to prevent the power loss that the Hard Disks generates. Is i add a diode to both the cable from the pc and the cable from the power supply, i will send to the hard disk a voltage of 4,3 volts instead of the 5 volt that is needed. All the other solutions in the comments are great but when i want to use the hard disk when it is not absorbing so much current, i dont need the external power supply so i can't just disconnect the red and black wire from the cable.

[PeterH293]

Since both supplies have a nominal 5V I don't see this as a problem. Instead you introduce the forward voltage drop of the diodes as a potential problem.

[PeterH293]

Nice one. I would, however recommend that the red and black splicings be made at separate points on the cable. Cut off the outer sheath in 2 separate places, make the red connection at one of them and the black connection at the other. Use insulating tape rather than heatshrink to cover the soldering. In this way you minimise the chance of a short circuit.

[Maurizio Miscio]

I agree with you Peter. Hower i think it's inconvenient to use that much length of cable to make a connection instead of using just a spot and insulate everything with the shrinking tube. I will use that technique in the future surely