Corsair PSU Peripheral to USB Power?

[MRoc]

I want to add some USB powered LED strips in my case. I don't want to route wires externally, I am using the few USB ports on the back of the case that I have. Internally, the USB header is being used by my cooling pump and the USB 3.0 header internally has a USB header for my mouse.

My PSU sits at the front of the case, its the tiny Corsair SF600.

My question is, is it possible or does an adapter exist to use one of the peripheral connection directly out of the PSU to a USB header? Any reason I shouldn't plug directly into the PSU? I could make said adapter myself and maybe put a resistor in line to reduce power spikes?

Any input would be helpful.

 

[[Spectre]]

Yes they exist for Molex to USB. I haven't seen one in a while but most that I have seen are fairly low quality though.

 

[GiGaBiTe]

I could make said adapter myself and maybe put a resistor in line to reduce power spikes?

The only thing that would do is start a fire, resistors are not supposed to be used as a transient suppression device.

I'm not sure why you'd even be concerned about spikes, a well regulated PSU only moves around fractions of a volt under load.

 

[Grebuloner]

What about a powered internal USB hub?

 

[MRoc]

I'm trying to keep from using a hub inside. Would like to draw power from the PSU since its so close to where the LED's would be.

 

[noxqzs]

Get a molex or SATA female connector and just use +5V and GND and be done with it. You would only need a resistor to limit voltage but you would have to be careful how much current would draw through the resistor. Usually that is only used for things that draw milliamps or less. You would want to use a fuse if you are pulling directly from the PSU lines. The RBG controller proabably has one internally but its always good practice to add one yourself if not sure.

THIS is something you are looking for, but if you have parts at home, its just as easy to make it yourself.

 

[GiGaBiTe]

You would only need a resistor to limit voltage but you would have to be careful how much current would draw through the resistor. Usually that is only used for things that draw milliamps or less.

Resistors are to resist current, not voltage. If you intend on driving more than a few LEDs, you need a regulator instead.

An LM7833 is close enough to the max forward voltage of most white/blue LEDs that it will probably be OK. It can provide up to 1 amp assuming the input voltage to the regulator is low enough (remember that linear regulators burn up wasted energy as heat, so the higher the input, the hotter it gets.) You'll also need a decent sized heatsink with thermal paste.

A buck switching regulator is also an option. It's far more efficient, has a higher maximum current output and produces far less heat. The only downside is that the output will be very noisy, and has a tenancy to backfeed RF into the source supply, which can create problems where signal integrity is important (ie. you may hear switching noise on audio outputs nearby.)

But if the OP is using LED tape, then current limiting resistors are almost always present for every few LEDs, so none of this is needed.

 

[noxqzs]

Thank you for your explanation, but my answer was more focused on using resistors as voltage dividers when the current needed for the circuit is small. After reading my original post, it does not sound right the way I worded it, in regards to resistors limiting voltage. They are in fact to limit current.

While your method is fine there are situations where a simple resistor will work. For example, if you want to attach an LED to a 12V fan header, then one resistor will suffice.a