Marquee light is way too bright. Can I wire in a resistor to dim it?

[justinjstark]

I just installed the marquee in my cab and the led light strip is way too bright.  Looking at the marquee is like staring into the sun.   

I think this is the light strip I installed.

I need to make the light dimmer.  Can I wire a resistor into the power line to make it dimmer?  I don't know anything about this.  What kind/size of resistor?  Is there a better way?

...next time I will install a dimmer light

[MonMotha]

Looks like you should be able to use a resistor, yes.  Not much electrical data posted on these things, but one comment gives the current consumption at ~300mA.

Try about a 15-22 ohm resistor.  It'll dissipate ~1-2W, so get a 3-5W resistor, and be aware that it'll get pretty toasty.  If you can't find a 3-5W, you can wire up 5 75 ohm 1/2W resistors in parallel to get a 15 ohm, 2.5W capable bundle.  These should be available at radio shack.  Any type of resistor should work in this application, including wirewound.

You could also just try hooking them up to a 9V or 5V power supply.  That will dim it substantially.  I'd recommend trying this before messing with resistors.

[justinjstark]

Looks like you should be able to use a resistor, yes.  Not much electrical data posted on these things, but one comment gives the current consumption at ~300mA.

Try about a 15-22 ohm resistor.  It'll dissipate ~1-2W, so get a 3-5W resistor, and be aware that it'll get pretty toasty.  If you can't find a 3-5W, you can wire up 5 75 ohm 1/2W resistors in parallel to get a 15 ohm, 2.5W capable bundle.  These should be available at radio shack.  Any type of resistor should work in this application, including wirewound.

You could also just try hooking them up to a 9V or 5V power supply.  That will dim it substantially.  I'd recommend trying this before messing with resistors.

I tried connecting the light to the 5V power and then it is so dim you cannot see it at all through the marquee art.

Is there a 9V connection anywhere on an ATX PSU?

[mgb]

I'm not sure this will do much, but what about the possibilty of putting another layer of something like a wax paper behind your marquee in order to better diffuse the light.

[justinjstark]

I'm not sure this will do much, but what about the possibilty of putting another layer of something like a wax paper behind your marquee in order to better diffuse the light.

This could work.

One thing that bothers me is that, while the marquee colors match beautifully when the marquee light is off, the marquee colors get a bit orange and don't match the cab so well when the light is on.  Maybe I could find a brown, semi-transparent material to put behind the marquee graphics.  Any ideas what I could use?  I will try to find a hobby store around here this afternoon.

[bkenobi]

I'm not aware of a 9v connection, but you can supply 7 volts by using 12v and 5v as the ground.

[MonMotha]

I'm not aware of a 9v connection, but you can supply 7 volts by using 12v and 5v as the ground.

This will decidedly piss off some power supplies.  It's not likely to be a problem on a fully loaded PC, though.  You can also get ~8.7V this way by using the 12V and 3.3V lines.

I was suggesting an external wall wart or similar.

[mgb]

Yeah, you could get one of those universal wall warts that you can set for different voltages (3.7v, 5v, 9v). I thaought Radio Shack had them.
also what is the quality of the marquee itself, maybe its too transparent?

[GibsonRiddler]

See if there is a stage lighting store in your city. They sell different colored "gels". It's used for stage lights to change colors or dimming.

[Savannan]

When I seen your post here I thought..what a great ideal and perfect for a marquee!  so I ordered one...after about a week of wondering where the hell my light is....I found out that it was coming fron HONG KONG!!! and it will take about 30 days to arrive..  its about 19" long and about 1/2" thick and lights up very good.  I have the defender style marquee with this light and it lites up very nicely.  I dont have the problem with it being too bright on my marquee. 

for those who order this..just be patient..its worth the wait...and also you get a neat shipping container too!! 

[llars]

How about something like a dimmer?

http://www.amazon.com/gp/product/B0000BYEF6/ref=pd_lpo_k2_dp_sr_1?pf_rd_p=486539851&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B000BQYKIQ&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=14XEMSM8YQTPV7DTVTDY

[mgb]

Yes you can.
They can get a little expensive though.
One guy I know bought special dimmers for his under cabinet led lighting and paid $80 per dimmer.

Here are some
http://www.superbrightleds.com/cgi-bin/store/index.cgi?action=DispPage&Page2Disp=%2Fhobby.htm&gclid=CPju5LS2s6cCFYHc4AodAjnhAg

[BobA]

You can use a fan speed control for a PC on the LED to dim it.   These only cost 4 or 5 dollars.

[Dervacumen]

What about the possibility [sic] of putting another layer of something like a wax paper behind your marquee in order to better diffuse the light.

I'm not sure this will do much, but what about the possibilty of putting another layer of something like a wax paper behind your marquee in order to better diffuse the light.

This could work.

One thing that bothers me is that, while the marquee colors match beautifully when the marquee light is off, the marquee colors get a bit orange and don't match the cab so well when the light is on.  Maybe I could find a brown, semi-transparent material to put behind the marquee graphics.  Any ideas what I could use?  I will try to find a hobby store around here this afternoon.

One thing that bothers me is that, while the marquee colors match beautifully when the marquee light is off, the marquee colors get a bit orange and don't match the cab so well when the light is on.  Maybe I could find a brown, semi-transparent material to put behind the marquee graphics.  Any ideas what I could use?  I will try to find a hobby store around here this afternoon.

Many years ago I used something called onion skin paper for tracing images but it was 8 1/2" x 11" so it may be problematic.  The paper was semi-translucent and brown.  I'm not sure what the real name is but it was commonly used in drafting and circuit tracing about, oh, say, 35 years ago.  It's probably still around if you check at an art supply store.  I imagine this would be a great application however you would have to be very mindful of applying it or any other material in equal layers to maintain a uniform translucency.

[justinjstark]

You can use a fan speed control for a PC on the LED to dim it.   These only cost 4 or 5 dollars.

Thank you.  This may be a good solution for me.