Topic: LEDs For Beer Pong Table (Read 93 times)

o The Drizzle o · « **on:** May 13, 2008, 02:49:00 PM »

well me and my one friend want to make a beer pong table (or beirut) for his house at school. we plan on using around 80-100 leds for it... but im not sure how to power all the leds though.
we plan on having it 8'x2'

heres a mockup i did of it... any suggestions?
(IMG:http://i13.photobucket.com/albums/a272/Ocelot13/thetable.jpg)

btw, we plan on having the leds around the border

kirky1991 · « **Reply #1 on:** May 13, 2008, 04:03:00 PM »

You could get a multi adapter that goes from 240/110v to 12v but with high amps, get a socket that fits the adapter wire it upto a switch and then just wire up all the LEDs in the circuit.

I geuss thats how i would go about it, Other more knowledgable people may have a better idea!

o The Drizzle o · « **Reply #2 on:** May 13, 2008, 07:11:00 PM »

is 12v enough to power that many leds?

lostboyz · « **Reply #3 on:** May 13, 2008, 09:40:00 PM »

lol voltage != power

voltage is potential

figure out the wattage of the amount of leds you are using then figure out how big of a 12v power supply you need.

o The Drizzle o · « **Reply #4 on:** May 13, 2008, 09:59:00 PM »

well im looking at leds on ebay... here is the stuff about them

Emitted Colour : Blue
Size: 5mm
Lens Color : Water Clear
Forward Voltage : 3.2V~3.6V
Forward Current :20mA
wavelength (nm):460-463-466
View Angle: About 25 degree.
Luminous Intensity: 5000mcd

and we're gonna be using anywhere from 80-125

SICKdimension · « **Reply #5 on:** May 14, 2008, 01:51:00 AM »

Ok, so for those LEDs, anything over 3.6V is a waste of power and you will need resistors, so if you had a 3.4V power supply, that would be perfect. Since that's unlikely, your best bet is to get a 5V source. Finding a wall wart that can handle 3Amps of power is unlikely, so you'll need to use another power supply. A computer's power supply will work for the job, as long as the 5V rail can handle 3A.

Then head on over to my site and get a bunch of LED Boards, resistors, and a PulseVU 2X to control them all

o The Drizzle o · « **Reply #6 on:** May 14, 2008, 04:02:00 AM »

thank you sickdimension...
well heres the plan. we want to wire up all the leds... but ive never wired leds up before.. ive read before on how to do like 3 or 4... but never anything greater. so im at a lost on what im gonna need. youre talking amps... lostsboyz is talking watts, im a bit confused haha.

i look for some ac adaptors.. i came up with this
http://www.action-el...adapter.htm#5dc

the hipro.. it says 12 volts dc and 3.33 amps

but heres an addition to the plan...
we want to cut out some spots in the wood to mount some cc tubes...
something like this
http://www.xoxide.co...-ccfl-blue.html

but they run off of 12v molex..
so would i beable to get a pc powersupply... mount it underneath the table in the boxframe... and use that to power everything? and if so... what all would i need?

btw, thank you so much for helping me with this

SICKdimension · « **Reply #7 on:** May 14, 2008, 05:57:00 AM »

Yep, an ATX PSU would do the job, and you can usually find a friend who has an extra laying around, if you don't have one. It needs to support 3A on the 5V rail and 1A (per cathode) on the 12V rail. Or, if you scrap the cathodes, you could just get the 5VDC-3A wall wart from that website and power the LEDs from that.

How it works, is each of your LEDs uses 20mA (.02A) when wired in parallel. So, 150 LEDs would be 3A. Now, since you're powering them with 5V, and they only need 3.4V, the extra voltage would damage that, so we need to "resist" that with a resistor. Use a resistor calculator to determine what resistor to use. Don't make your sets of LEDs too big; I would recommend using one resistor per 10 or so. If you do use those LED boards, you can put one resistor per board, which would be an 8.2 ohm 1 watt resistor.

There is a way to power the LEDs in series to 12V if you wanted to get just teh 12VDC-3.33A wall wart to power them. If you did it this way, 150 LEDs would be 1A instead of 3A, but would require some more tricky wiring and more resistors.

Hope that wasn't too confusing. Basically you're going to need to plan ahead how you'll wire it, so you know what resistors to get and how many, then get a ton of LEDs, thick wire, and patience. It will be a lot of soldering!

hamwbone · « **Reply #8 on:** May 14, 2008, 09:03:00 AM »

all i wanna know is if i can play beer pong with you when your done..? hehe

twistedsymphony · « **Reply #9 on:** May 14, 2008, 12:26:00 PM »

a PC power supply is overkill, not to mention it needs a good amount of ventilation and you're going to be spilling alcohol all over this thing....

Typically when you start using more than a dozen LEDs it's a good idea to look into LED driver circuitry.

here's a real simple circuit: http://www.discoverc...tcurretled1.htm

Here is some other information on simple circuits to drive large amounts of LEDs: http://wolfstone.hal...nSeriesParallel

Then there are more professional solutions that are designed for LCD backlighting and other consumer product applications... these use Pulse Width Modulation to keep stress on the circuit and the LEDs to a minimum and extending their lifespan over 4 times what you'd get with a constant current system: http://www.fairchild...ed_drivers.html

o The Drizzle o · « **Reply #10 on:** February 03, 2020, 02:05:00 PM »

ok, id first just like to thank everyone for helping... so thank you kirky, lostboyz, sickdimension, twistedsymphony, and hamwbone.

ok.. now.
so, youre saying the best way would just be to get a 5 volt 3 amp adaptor.
then wire the leds up in sets of like 10 which a resistor for each set.
so ill have like 15 sets.

and then if i use a power supply... am i gonna need a 12 volt rail for each cathode? (or i guess looking at the lights, it says it has 2 output connectors.. so i could run 2 off of one rail, right?)

so if we did 4 lights... we'd need a power supply with dual 12 volt rails, which each ral at 1A? correct?

i found this power supply on newegg...
http://www.newegg.com/Product/Product.aspx...N82E16817148033
it has two +12v rails, and it has a +5vsb rail at 3A (is +5vsb 5 volt?)
basically... would that be good?

and about spilling stuff on it... it would be mounted up underneath the table, under the woodtop. we plan on coating the top with some clearcoat to protect the wood from getting wet and we also plan on putting a big sheet of glass on top too... so it should stay pretty dry.

edit: oh, and what size of wire should i be looking into... 28 awg? or...? and whats a good place to get wire from.. ones that wont rip you off like radio shack does with leds..

This post has been edited by o The Drizzle o: Yesterday, 10:08 PM

SICKdimension · « **Reply #11 on:** May 14, 2008, 06:40:00 PM »

Ya, that PSU looks like it will work fine. It seems to have a powerful 3.3V rail as well, so you could use that and not use any resistors for your LEDs, making wiring much easier and more efficient.

The 12V rail looks powerful enough to handle a few cathodes also. YOu don't need separate rails for each cathode, but the specs said that each requires .7A, so allow for that.

Yes, a PC PSU is overkill, but it'll do the job and is easy to find, in my opinion. Since it easily handles 3A, you don't necessarily need to add circuits to make the LEDs more efficient, but that doesn't hurt. If you hook them up to the PulseVU 2X, which handles 3A, then if you have them on the dim setting, or any setting other than on, they'll be pulse width modulated, thus making them more efficient.

5Vsb is 5 Volt Standby, meaning it is always on, whether the PSU is on or not.

For wire, you'll probably want a lot of 24awg and use a strand of that for each set of 10 LEDs. Fry's is a good shop for wire and electronics parts, or I'm sure you can find some on ebay, etc.

o The Drizzle o · « **Reply #12 on:** May 14, 2008, 07:39:00 PM »

so, when i look for a power supply... i just need to look for one that has a 3.3V rail at atleast 3A and a 12V rail at least, 2.8A since we plan on running 4 of the cathode tubes...
aslong as the voltage is right, you can have more amps than needed, right? so i could run the 150 leds off of a 3.3V with say 28A available? because i found a rosewill power supply that has a 3.3V rail at 28A and a 12V rail at 15A.
http://www.newegg.co...N82E16817182001

am i on the right path?

o The Drizzle o · « **Reply #13 on:** May 14, 2008, 08:14:00 PM »

oh another question... if i use the 3.3V rail... i wouldnt need to use resistors...so would i beable to just wire more up together? like have 4 sets, 1 for each side?

SICKdimension · « **Reply #14 on:** May 14, 2008, 10:45:00 PM »

Yes, you can have more amps available. I'm not 100% sure, but I think when they give those ratings such as 3.3V-28A, that means you can get 28A from 3.3V if that is all that is connected. If you are pulling 3A from 12V, then I'm not sure you can still pull 28A from 3.3V. Basically, I think they give you the 'best case scenario' amperage ratings, so expect less. ... I could be wrong on that theory though.

If you're using 3.3V, then how you wire the sets depends on your wire thickness. For example, a chart I just found says that 24awg wire can support .577A, so you wouldn't want to have more than 25 LEDs from one 24awg wire.

Author Topic: LEDs For Beer Pong Table (Read 93 times)