Author Options:

How to power 12V LED Strip with 5V USB via Computer Mouse Controller? Answered

Hello, I'm a electrical idiot, really appreciate it if you could explain in layman terms. I want to use the mouse electrical board, to power and control colours of my LED strip. This is for the chassis and random lighting. Note that I HAVE to use the mouse circuit board to control LED strip colours (Not Power Supply, but preferably so to reduce clutter)

So, I would have to remove the LED (which have 4 connections) from the mouse, and replace it with my LED strip via soldering wires. the connection would then be desktop/laptop pc - usb port - usb cable - mouse board - led strip (am I right?)

I bought 12V LED Strips with the following specifications below. I will only be using 3 sections in series, each section has 3 LEDs, total 9 LEDs. This means a total power requirement of 1.8Watts right? But the LED strip is 12V, whereas the USB mouse is 5V. Since its only 3 sections, is 5V sufficient? Again, i'm really noob at this.

The LED strip coincidentally also have 4 ports/wires. +12V, R, G, B. I'm assuming RGB ports are for the controllers, while +12V port is for the power supply.

Color: RGB (Red Green Blue) Flash SMD LED
View angle: 120°
Working voltage: DC 12V
Power: 0.2w/led ; 60w/300leds;
Working Current/5Meter: 5A
LED quantity: 60LED/m, 300 LEDs
Lumens: 900LM
Operating temperature: -20 to 50 °
Lifetime: 50,000+ hours
Size: W10*H2mm

Thanks for your help!



2 years ago

Standard USB are limited to 500ma @ 5v = 2.5watt and a USB 2.0 can deliver 1500ma @ 5v = 7.5watt..

You need 9 LED x .200w = 1.8watt thats 150ma @ 12v... You could use a 5v to 12v converter to run the LEDs https://www.adafruit.com/products/2778 who claim to deliver over 200ma @12v...

BTW the RGB LEDs I'm familiar with have the two outside wires are usually +12v and ground, the other two are data and clock.

Okay, lets not quarrel here. My objective is not to power the LED strip through USB. My objective is to use the mouse's board to control the light settings. Power source doesn't matter (of course it would be good if i could power through usb to reduce clutter, but since i can't, it's okay).

Since I can't power it through the USB, can I use the mouse's board to control the lights, and the power comes from a separate power supply provided with the LED strip? I drew a newbie schematic, hope its good enough to understand! I drew a present situation which is what i currently have and works, but not what I want.

basically, does this proposed situation work?

2016-02-04 09.00.44.jpg

Here you go. The 12v DC Power Supply must have a return ground.

The big unknown that Steve tried to point out is ;

When a transistor in the Mouse Board turns off the red color it must stop current flow and withstand 12 volts from the led sections.

Maybe the engineer who designed the Mouse Board put in a 25v transistor, are you willing to risk it !?

BTW I have a curve tracer that can tell me if the transistor is 60v or 8v capable.

Otherwise you need to use Omnivent's three drivers to guarantee proper operation.


i see i see. So the 12V from the PS goes through the LEDs, and to the mouse board, and highly likely frying the mouse board right? which is what omnivent was trying to say below? that cleared things up alot. Based on the same schematic i drawn, if i use a 5V LED strip instead of 12V, and simply replaced the mouse's LED, that would work right?

Right, conditionally...

If you are good at soldering you may change the resistors on strip and turn it into a 5v strip.

I presume the mouse leds are one of each color and use much less current, in fact an LED could be running directly off a micro pin which could not handle 100ma needed by the strip....

probably not changing the resistors. probably gonna buy another 5V LED strip.

The mouse only have one LED. and i saw 4 wires coming out of the LED little tiny board, with those 4 wires connecting the mouse LED to the mouse mainboard. I have no idea what a micro pin is haha.

A uP = microprocessor = miniature computer. They are made with 8, 16, 32, 64 and up integrated circuit electrical connection pins. The pins are for power, digital or analog input and digital output. The digital output is a low level 0-5v signal that may sink or source 3 to 10ma which will light one led but cannot handle 100ma which is more then the entire uP consumes...

thanks for your reply.

in that case, isn't my needs of 1.8watt, 150mA less than the usb supply of 2.5watt for standard usb, 7.5watt for usb2.0? the device will only draw the amount of power it needs right?

I want it to go through the mouse circuit board because the software recognises the mouse and changes its LED colour accordingly. so, a software changes the mouse led, but instead, I want the software to change my own LED. therefore, I have to use the mouse circuit board to control the LED's colours.

the LED strip I have looks like this in the attached image.


obviously, i'm trying to find a way to make it work...... not constructive at all

What isn't constructive ? I'm telling you you can't do what you want with what you have. It might not help you, but it should stop you trying and destroying your PC by inappropriately connecting a 12V supply to a device which can't handle the voltage or LED current.

To do what you want with what you have will need to know you can pull 500mA from the mouse, and as I suggested in my reply to Iceng, since its a mouse, its probably only capable of asking for 100mA from the USB port.


We try to help You just joined and could be surprised at how Engineers can be strongly worded when explaining the facts of a situation to people not versed in electrical engineering. Take no offense.

We have been more stern with people who want to violate thermodynamics and create perpetual motion devices.

C Chaplin.jpg

PS. These aren't addressable LEDs, looking at the OPs link

It can only deliver that maximum current if the slave asks the master for multiple units of current, in, IIRC, 100mA chunks. , if the device is a mouse (1 unit), the mouse CAN'T ask for more power.


You need to add 3 (or 6 depending) transistors (plus some resistors) to let the mouse board drive the strip(s). The strip(s) will have one pin at +12V and the RGB lines going to the transistors. The pads where the original RGB LED connected it's RGB pins will drive the transistors through resistors.

That's all there is to it - can you read and assemble from a schematic?

hi, i replied at the above post, would that schematic be possible?

You need a driver in between and if your info is mint, you'll need the attached circuit times 3 (one for each line R, G and B (their +5V and their grounds would be common for all 3 and the total circuit could be made on a.small piece of Vero board.

I do have a feeling that this may be over your head though, but if you decide to go on, I'll help you with a shopping list and the assembly - do you have a soldering iron? You can get the components and board from e.g. Elfa.


2 years ago

You are correct there is a a 12v line and you can turn on any or all colors RGB by grounding the other wires. Basically ON or off. It will not hurt to try running on 5v, just very dim if it lights at all.

would the schematic in my post above work? Mouse board supplied by USB, my LED strip supplied by 12V power supply

Different strips have to be connected in parallel...

What do you want to control?
Or: How is a mouse supposed to change colors for the LED's
But in any way you can not power a 12V strip with 5V.