Cold cathode moonlight with "parabolic" reflector

kwirky · #1 10-01-2006, 08:18 AM

I set up a cold cathode moonlight over my 120 tank.

It's a cold cathode light, used for lighting inside computer cases, by those who are mod crazy. I had one kicking around, that I had used a LONG time ago, before I got sick of case modding.

I made a reflector out of a length of 1.5" pvc, which I split down the middle, getting a 180 degree reflector.

I figured I'd go one step further, and make it "parabolic" by cutting a piece of coathanger that would run down the length, and glueing it on before gluing on the alluminum foil. I painted the PVC black to math my light fixture.

here's the finished reflector:

I quite like the look of it on the side of the tank. It gives a "moon just came up" effect, which I haven't really seen on a tank before.
Here's the light over the tank:

If you're wondering, You can get the cold cathode light at The Source for only $15, which isn't a bad price. sku: 261-1218
I'm using a 4.5V 500mah power adapter. If you need something brighter for your own tank, run a higher milliamperage.

Note: that photo was at F22, 120 second exposure.
That's the actual brightness of the light, when you just flick off the room's lights, and your eyes haven't addapted to the light yet. After looking at it for about 10 seconds, your eyes adjust, and you can kind of start to see things in the dark areas.

Overall, I like cold cathode moonlights, since they're not a point source light. I had used LED moonlights before, and they're too focused, and don't look natural. And I'm sure the animals don't like them running ALL night, if you time your lights that way.

Oh, and a tip. if you go to a source store, ask them if they have a "junk box in the back" with power adapters you could buy a power adapter from. You might get a power adapter for $2 instead of $25

look for a really messy store. they'll have junk boxes

Kabong · #2 10-01-2006, 04:17 PM

Here's a pic of my 10 Gal with a cold cathode moonlight as well.

I just attached mine directly into my existing canopy.

Chin_Lee · #3 10-01-2006, 05:02 PM

I use the same thing and I agree they have a much less spotlight effect than LEDs.
word of warning - don't put your magnet cleaner on or near the transformer box. I fried my first one doing so.
Then I fried my second one by putting the wrong polarity on the wires.
My third and last one has been working for the past couple of years

kwirky · #4 10-01-2006, 07:42 PM

Quote:

Originally Posted by Chin_Lee

word of warning - don't put your magnet cleaner on or near the transformer box.

thanks for the tip, didn't know they were sensitive in that sense.

Reefer Rob · #5 10-02-2006, 12:48 AM

Has anyone tried these with a 12v power supply, or would it be too bright. This is the voltage of the yellow wire on a computer power supply.

Tarolisol · #6 10-02-2006, 01:46 AM

Very cool. I'd like to do that but electrical lights like LED and those i cant figure out.

Kabong · #7 10-02-2006, 01:59 AM

Quote:

Originally Posted by Reefer Rob

Has anyone tried these with a 12v power supply, or would it be too bright. This is the voltage of the yellow wire on a computer power supply.

Mine is run off a cell phone charger plug,
So techniacly it starts as 12v.
But I believe it go's through some resistors.

Reefer Rob · #8 10-02-2006, 02:16 AM

OK, I hooked it up to a an old transformer from a cordless phone. 9V, 210ma, and what do ya know, it works! Looks great with no reflector, not sure if it might be a bit too bright though.

Reefer Rob · #9 10-02-2006, 07:16 PM

I think I'd like to go with 2 tubes with a lower output from each if posible for a more even ilumination of the tank at night. Each tube is rated at 3W which means a 250MA draw at 12V. I'm trying to size a transformer to run 2 of these. If I go with a 6V transformer does anyone know if it will still draw 250MA making it 1.5W, or will it draw 500MA each?

kwirky · #10 10-02-2006, 11:23 PM

they run optimal on 12v, but it's WAY too bright.

I ran mine off 4.5V, because 9v was too bright. I think if you're using two of these lights, try to run them 3 volts each. I used a reflector on mine, because I wanted the light to be shielded from the eyes, making it easier for the eyes to adjust to the dark. I still don't have it positioned over the tank well though.

most cell phone chargers are 5v. some are 4.5v