Building an LED panel!

Ok so I want to build a panel of led lights that will be very bright. I bought 100 white leds that are 30,000 mcd. Now to wire them up without putting 100 resistors (a resistor for every bulb)...how do I do that? Do I wire them in series or parallel? Do I increase my source voltage or what? Because I am smart enough to know that I will need resistors somewhere. But I'm trying to cut my cost a bit. I first got this idea from this video...http://m.youtube.com/watch?v=NkkU0UO3sek ... Check it out I think it's pretty cool.

Increase your source voltage and wire them in series. Really cuts down on the amperage needed. If you have a 24V source, then you can get at least 6 in series (assuming 3.7V Vf), drawing 20mA. 16 strings of 6 LEDs each then need 320mA. Or 12V, 640mA.

Why bother!

20ma per LED... 10watts of power for example.

http://www.ebay.com.au/itm/Super-Bright-Integrated-LED-Light-Beads-10W-Lamp-Energy-Saving-Chip-Pure-White-/130784781050?pt=AU_Lighting_Fans&hash=item1e736162fa

Total cost from ebay, $1.96.

10watts = 833ma @ 12v, but these 10watt LED's are quite happy at 1.2amps (Around 50 20ma led's worth) with adequate cooling

Time saved is immense.

Except he already bought the LEDs.

Google "LED wizard": http://led.linear1.org/led.wiz

That only tells you what I discussed in #1 already. Without telling you the why.

Want to see a flashlight/torch?

check out this beast.....

http://www.fenixlight.com/ProductMore.aspx?id=84&tid=12&cid=1#.UhoTMH_C4iQ

What if you mount one of these in a holder? https://www.sylvania.com/en-us/products/automotive/Pages/silverstar-ultra.aspx I don't know how many Lumens they are.

Here's a video of the device gives better stats, it looks brighter than the headlights though...

http://www.youtube.com/watch?v=iTICDnZ6UTs

CrossRoads: Increase your source voltage and wire them in series. Really cuts down on the amperage needed. If you have a 24V source, then you can get at least 6 in series (assuming 3.7V Vf), drawing 20mA. 16 strings of 6 LEDs each then need 320mA. Or 12V, 640mA.

Thanks so much for the help here. So if I just keep increasing the voltage...the more LEDs I will be able to put into series? Is that right?

Pretty much, but you have to allow for the variability in the total voltage drop across the LEDs with temperature, so do not expect to control the current with a resistor dropping a couple of volts. You really want a constant-current driver for each chain of LEDs, using either a linear design or one of the switchmode modules made for this purpose (though usually for the higher power LEDs).

Paul__B:
Pretty much, but you have to allow for the variability in the total voltage drop across the LEDs with temperature, so do not expect to control the current with a resistor dropping a couple of volts. You really want a constant-current driver for each chain of LEDs, using either a linear design or one of the switchmode modules made for this purpose (though usually for the higher power LEDs).

Ok can you give me an example or link as to where to get these constant current drivers? I’m trying to do this as cheap as possible. Because I have 8 panels that are 12"x7 3/4" that want covered in LEDs. Is this the cheapest way or is there any other ways of doing this?

All this temperature and constant current stuff - it’s not like this is about designing a calibrated light source.

Just stay with what CrossRoads suggested immediately previous, bunches of strings with their own dropping/limiting resistors.