Want to make CPU Lights from CCFL

kosmonavt

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Jul 8, 2010
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Hello guys,

I have a couple of cold cathodes that I took out from an LCD screen. I want to make CPU lights from them. Is it OK to simply hook the CCFL to its inverter and join the inverter to one of the free power outlets inside the box? Should I connect it to the +12V DC supply or the +5V one? Could anyone clear me about the pinout of the inverter? (The end which is hooked up to the laptop motherboard.)

Moreover, are these CCFLs safe to use? These emit UV radiation and I believe there is a filter on the LCD which filters out these rays. Now that they are without that filter, is it safe to use them?

Thanks in advance.

Also, is it possible to hook up TWO CCFLs to a single inverter? (I only have one :( )

As long as they are in parrallel, I believe it would be OK, is it so?
 

extreme30

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Nov 1, 2010
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it's safe to use, yes can hooke up 2 ccfl in 1 inverter, as long as your inverter can handle it, connecting your inverter to 12v or 5V, most inverter are connected at the 12V, well check your inverter power input, just to be safe.
 

kosmonavt

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Jul 8, 2010
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I don't know if this inverter can handle two CCFLs or not. I just pulled it out of a laptop. By handling, do you mean if they can "physically"handle them? No it cannot. I has only one output connector. SO is it OK to strip off the conector and connect the two CCFLs in parrallel on the output port?

Also, this one has six wires for the input. Can this help you figure out EXACTLY if this is a 5V or 12V inverter? The laptop was quite old though (year 2000).
 

kosmonavt

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Jul 8, 2010
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OK Guys, seems like I have to figure out this on my own but few other queries. According to this:

http://www.idiots.org.uk/images/xenarc_inverter_data.jpg

Brown = Supply Voltage (+12VDC)
Orange = 0V (GND)
Yellow = Brightness Control Voltage
Green = 3.3V

My inverter has six wires connecting it to the motherboard. Four of the above mentioned colors and a Red and a Black one.

The inverter came out of a Compaq Armada E500 laptop. Could anyone give me the pinout of my inverter? How am I going to hook it up into my PSU? I can take 5V and 12V from a 4 Pin Molex Peripheral Connector and 3.3 V from the AUX connector.

The question is, what are the purposes of each of these wires and do I actually need all of them? The website for that image says that when the brightness control voltage is zero, the lamp will glow at its brightest so I will not be supplying any brightness control voltage. What about the 3.3V one? What is it used for? What are the Balck and Red Wires for?
 

dEAne

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Dec 13, 2009
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Their is a schematic for that, checked this out -
http://en.wikipedia.org/wiki/Inverter_%28electrical%29

It is good to test this thing outside the unit not on the motherboard. A multimeter is also a good tool.

Black is the supply voltage. Red is the ground (neg). These two supplies your CCFL. The 3.3v supply your inverter and the yellow is the controller (should be to connect another circuit to control the brightness). Careful.
 

kosmonavt

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Jul 8, 2010
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THanks a lot dEAne!

Its strange though, how come do Red and Black supply the CCFL? Isn't the voltage supplied to the inverter the one which is converted to high voltage AC?

I am not talking about the 3.3V one. THe Brown wire (as I mentioned above) supplies 12 VDC to the inverter and the Orange one is the GND.

What's the use of the Red and Black wires then?

Also, can you please acquaint me with the purpose of the 3.3VDC supplied to the inverter? I can take the 3.3 V from the AUX connector. Is it OK?

I believe it is OK to leave the Yellow one disconnected. This makes it 0 V and the lamp is brightest at 0V, any suggestions?