I want to power a water pump with usb port but their voltages dont match. What should i do?

A friend of mine showed me a project in a magazine he thought it was really awesome and unusual but i knew i could make it. Although the mag didnt tell how it works i made a design in my mind. i need to power a water pump via usb. I can easily access a 12 volt pump and 5 volt usb but the usb voltage isnt sufficient. Can i find a lower voltage pump or increase the voltage of the usb, please help?

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orksecurity6 years ago
A DC-to-DC-converter circuit can step up voltage, but doing so will reduce the current (amps) available by the same amount. (There's only so much power available, and power in watts is volts times amps.) Since the current available from a USB port is limited, there may not be enough left to run the motor. Plus, the conversion will lose some power along the way just because nothing is ever 100% efficient.

A 5V pump sounds like a better bet, if you can find one that will run on less than 500mA of current yet provide the pressure and volume you need. (And getting 500mA from a USB port requires some logic to negotiate that with the port; I think the default setting limits it to 100mA.)

There are a couple of different 5v solutions out there. Check out some of the ballast pumps from RC submarines. Search google for 'RC Sub Workshop' to see there's.
Another option is to go with various PC CPU cooler pumps which are often designed for 5v systems to begin with. There are all sorts of these out there although some of them are more geared to 10v. If you want really small and don't mind paying a little more, there are some really slick little ones from TCS micropumps in the UK.
Venemot (author)  orksecurity6 years ago
Well the problem is a 5v pump isnt easily accessible..i can easily find a 12v pump.have you ever come across a 5v pump, if yes i will continue my search and hopefully i migh find it.although i live in a place where i cant find most of the thigs i need.
6V pump might run well enough. A 6V pump running on four batteries is going to spend a lot of its time running at 5V anyway... Or you might need to get pump and motor separately, or swap out the motor.

Again, this is going to have to be a _small_ pump, since there just isn't much power available there.

If you tell us more about what you're trying to do, someone may have a better way to do it. Or you could consider using a battery pack rather than insisting on plugging it into USB.
Venemot (author)  orksecurity6 years ago
its is just a sort of fountain....there are going to be a few steps and the pump will pump the water to the highest step and the water will flow down and the process will be repeated.
And i can use a 12v battery pack.That is very easy but i want to use usb.i want a beautiful display with my pc.
adana Venemot6 years ago
Hi! How did your project turn out? I'm trying to find a good USB-powered water pumping solution too. What did you end up using?

Venemot (author)  adana5 years ago
I haven't found a solution to this, yet. I just a bubble gun. It runs on three AA batteries. The bubble solution is pumped by a small pump. Although it isnt very powerful, but it fits it's purpose. Although it has raised my hopes and I will search for the pump. And the delay is because i had months of exams, and now they are finally over. My heart is light today. It is flying way above the clouds today.......
adana Venemot5 years ago
I've been working with a little 5V pump I found here:


It's cute, small, seems to provide the 1 liter/minute it claims, and runs from the USB 5V. Maybe that will be an additional option to consider.

Congratulations on your exams being over!
smcneill26 years ago

This might work for you.
anuk076 years ago
why don't you build a power supply of 12vdc..........it will convert your wall outlet Ac into 12VDC and required currents can be easily achievable.....
Venemot (author)  anuk076 years ago
i can do that but i want to connect it to pc via usb.
anuk07 Venemot6 years ago
you can enter vin minimum and vin max, desired o/p current and voltages then click on open design....
Venemot (author)  anuk076 years ago
can you please elaborate..!!!
anuk07 Venemot6 years ago

this is the link...
click on it......
there will be various options there...
for getting the detailed circuit click on "open design" from the list of designs created using various IC's....
but remember to do that u have to sign in... it might take some time for the activation of your account but it's good....

but remember don't try these circuits on bread boards....because these are delicate circuits and i was also instructed to not to test these circuits on bread board....

good luck!!!!!
anuk07 Venemot6 years ago

You can build this.....but you know you need exact components.....
hoddy6 years ago
You could get 12v directly from the pc power supply (box inside the pc witch powers all the components for example the hard drive). A standard Molex connector (4 pin) using Pin 1 and 2, yellow and black should give you you 12v. I'm not 100% sure on the current output but im assuming you pump isn't to big.

For more info try here:
and go to section:
Disk drive connector (Molex 8981 Series Power Connector)

Hope this helps
Venemot (author)  hoddy6 years ago
Right now i use a laptop so i cant do that. Although i am going to buy a desktop i dont want to destroy it for such a small project.and by the way i want it to be usb.if not i can easily connect it to mains outlet with a 220v ac to 12v dc converter.or a 12v battery.
by the way thanks for replying
hoddy Venemot6 years ago
I think a 12v PSU sounds like you best bet, unfortunately your only ever going to get 5v from USB, unless you step up the voltage but you will lose valuable amps. Sorry I cant help any more but good luck!