Mac USB Power Output Control

[abhishgva]

Hello all,

Does anyone know of a software that can allow a Mac user to control the power output of their USB ports?
The main thing I'd like to achieve is to reduce the maximum output made available to an arbitrary amount. I have a USB fan, and if I can achieve this, rather than it always running at full speed, I would be able to lower its speed by reducing USB power output.

I know of a software for windows that allows users to control their cooling CPU fan speeds.

I was hoping for something along the same lines but for Mac USB power output control.

Any ideas?

 

[RadDave]

Hello and welcome to the forum! Please provide more information that likely will be of help to those responding: 1) What Mac do you own (be specific w/ model & year); 2) What OS X is installed; 3) What do you currently have attached to the USB ports; 4) Why do you believe your fans are 'running at full speed'; and 5) What have you tried so far? Dave

 

[abhishgva]

Hello and welcome to the forum! Please provide more information that likely will be of help to those responding: 1) What Mac do you own (be specific w/ model & year); 2) What OS X is installed; 3) What do you currently have attached to the USB ports; 4) Why do you believe your fans are 'running at full speed'; and 5) What have you tried so far? Dave

Sure RadDave,

Mac model: Macbook 15'' Retina 2014
OS: Mavericks - 10.9.5

What is attached to the USB port is a USB fan (link)

The fan runs at only 1 speed, and this default speed must by definition be it's maximum.

I remember using LabView once on a windows based laptop to supply voltage in a sinusoidal pattern to a particular USB port. This allowed me to have an LED I had attached to it to grow brighter and then slowly dimmer and oscillate like that forever.

So this leads me to believe that supplying a specific voltage to a USB port should be possible (within it's designed range of course).

I haven't tried using LabView on my mac to solve this problem, and would much rather find an easier (lighter) method of doing so. Either through a pre-existing software, or to just be told which settings on my mac (wherever) I could possibly fiddle with to obtain the desired change in USB voltage output.

Cheers,
Abhishgva

 

[chscag]

I don't believe the output voltage or current from the USB ports on your rMacBook can be controlled. My question to you though, is why do you need the fan? Your rMacBook has no internal fan and is designed to run cool at the temps set by the Apple engineers who designed it.

 

[harryb2448]

Methinks this is an external fan to keep the user cool Charlie, not the machine.

 

[abhishgva]

yes haha, this is a fan for my face! it has nothing to do with cooling the laptop.

Which is why I'd like to be able to regulate its speed. Because it can be too powerful.

 

[techiesteve]

I'm not aware of any way of any way of varying the 5V output on the USB sockets. Apple designed the USB interface to supply a stable 5V, there is no logical reason for them to to have made the 5V variable.

Options may be to see if anyone makes a variable speed USB fan, a battery powered USB fan or a mains powered variable speed fan. More complex would be to design an efficient switching voltage regulator fed from the USB ports 5V, as a linear regulator would likely have too higher forward voltage drop. Possible if you are an electronics engineer with time on your hands, otherwise completely OTT.