powering cold cathodes (electricians)

[Fishboy93]

I plan on using 4 cold cathode tubes on my 5.5 nano tank, and I was wondering if the ac/dc converter i have would be enough to safely power them.
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AC-DC adapter: Output 12v 200mA
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Cathodes: Tube diameter: 3.0mm. Tube length: 300mm/100mm. Input voltage of inverter: 12v. Output voltage of inverter: 680v. Current draw: 5.0mAv. Brightness: 28,000~30,000 cd/m2. Lifetime: 30,000 hours.
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It says 5.0mAv what exactly does this mean and will this work?
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any help would be greatly appreciated
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thanks

[Todesengel]

5mA = 5milliamps. Its a measure of current.

Your AC-DC adapter has an output of 12v at 200mA

Each one of your cathodes take 12v at 5mA. You can easily run 4 cold cathodes on that power supply.

5mA * 4 cathode tubes = 20mA

[funman1]

Yes it will work, but
Just watch out because they put out HIGH voltage of that inverter!!!
Basically what you have is "Neon" more or less.

[Fishboy93]

thanks for your help i knew i could count on you guys, but funman i'm not quite sure what you mean. Are you saying that the AC-DC inverter may be too much, or that the second inverter that takes the 12V in and turns it into usuable voltage for the tubes is high voltage?

[stugray]

Based on the info above:

AC adapter - 12V @ .200 A = 12*.2= 2.4 Watts - This is what your power supply is capable of delivering.

You say the cathode uses "Output voltage of inverter: 680v. Current draw: 5.0mAv."
This means:

1- If the specified current draw from the 680V supply is 5.0mA, then:

Cathode: 680V @ .005 A = 680*.005 = 3.4 Watts

You plan on using 4 of them that is a total of 4*3.4 = 13.6 Watts

2 - Now if you mean that the 680V draws .005 Amps from the 12V supply, then the total power is:

Cathode: 12V @ .005 A = 12*.005 = .06 Watts

You plan on using 4 of them that is a total of 4*.06= .24 Watts ( I dont believe this for a light output )

So, my first guess is that the first number is right and you need at least 15-20 Watt 12V power supply.

Stu

[Fishboy93]

so basically it isnt going to cut it?

[Fishboy93]

how about a pc power supply i have some old computer parts laying around the cold cathodes are made for lighting up a pc case, i think i have a 250watt power supply laying around....or what about a laptop power supply that might meet the requires wattage....so as long as its >20watts and 12V i'm good?

[ludnix]

A PC powersupply would work fine, seeing as there are people running more than 4 cold cathodes in their computers in some instances, even with low wattage power supplies.

[Fishboy93]

if i have a 250 watt power supply it won't use all 250 watts all the time right?

[jasonh]

Nope, that's the max it'll output.