Photo of Antec snakelight part

Otto69 · Post by **Otto69** » Sat Sep 22, 2007 9:40 am

Some of you may be aware that the mirrored version of the 182 case, the "SE" model, comes with a built in snakelight. My inner pimp was enthused by the concept so I ordered the part from Antec to fool with. Here's a gimpy photo:

The unit comes with a double wiring option: 4 pin molex or a USB header. Because a tool like this is most useful when the power supply is turned OFF, I hope to wire this up to run off AA batteries. I have an email into Antec asking about voltage it will run on. I'm pretty sure it's an LED light. The only question is if there is a resistor wired in somewhere.

it's a nice looking light, the only bummer is mine didn't come with screws to attach it.

bonestonne · Post by **bonestonne** » Sun Sep 23, 2007 11:58 am

no, i doubt there's a resistor. most dim LEDs are 3v, however brighter LEDs are 5v. that light has a USB header and molex header both wired to draw 5v. [thats why it can run off USB, USB buses supply 5v dc current]

you may have to experiment with running it, a 9v battery would be fine [i've overpowered LEDs with no adverse effects so far]. AA's would be a hassle, needing 4 to power that, AAA's would be the same, but i don't think C or D cell batteries would even be worth it. 9v batteries however would in theory work perfectly fine with it.

Trekmeister · Post by **Trekmeister** » Sun Sep 23, 2007 1:24 pm

There might be a resistor up in the LED housing, but no way to know for sure without opening it. So go get that screwdriver!

Like bonestonne pointed out it clearly runs on 5V. But powering it from 9V sounds a bit excessive to me, I would not do it in fear of the LED going up in smoke. Might work, might not.

Anyhow, if you do open it up and there is a resistor you could remove it and run it using a lower voltage (meaning fewer batteries). Or you could measure the current when running it on 5V and then solder a suitable resistor in series and run it from a 9V battery.

disphenoidal · Post by **disphenoidal** » Mon Sep 24, 2007 4:24 pm

There has to be a resistor in series with the diode, to limit the current through it. I think the forward voltage through white LEDs is pretty high, maybe as much as 4V, so whatever you power it with must provide at least that much voltage. Assuming a 4V forward voltage, and 20mA current, running it off a 5V supply would require a 50 Ohm resistor. Running the same diode of a 9V supply, at the same current would require a 250 Ohm resistor. So, you need to add a 200 Ohm resistor in series with the existing one. These numbers are just approximations, I don't know if the forward voltage really is 4V, or the current really is 20mA, but something along those lines will work.

Stany · Post by **Stany** » Fri Sep 28, 2007 1:06 pm

I wouldn't take a forward voltage of 4V , 2V is more then enough,and yes 20mA is an ok current. So on 5V you would need a resistor of 3V/0.020=150ohm. But I think it's already taken care of internally ...

Otto69 · Post by **Otto69** » Fri Sep 28, 2007 5:41 pm

Well, Antec responded. First with:

"Comment: did you buy the sanke light from us",

and after I confirmed that,

"it is 5 volts"

So I don't know if there's a resistor in there or not. I may have hit a newbie support person, or maybe they're having as much trouble with the customer contact email as I am

I just found a response to an earlier question I send them but when it arrived I mistook it as a confirmation email. Their system produces about a page of boilerplate text per message and the response from the support people is in sort of buried in the middle.