multi led battery needs

[fawnheart2000]

I am working on a Holoprojector project and would like to place more than one led (royal blue) say two or maybe three in series. I need to know how many and what type of battery to get the most out of them.

[987654321a]

that would be hard unless its a think one, but its possible. you would need a huge heatsink, a gigantic battery pack like possibly 40volts (ok just a joke, but its big!) its possible with 1 watters as they dont give off much heat and therefore will work.

[xwingband]

I'd first wonder what size of a projector is this? Is it like the bubble tape size one in the costume forum?

If so three would blind a person.

[987654321a]

and would that not be possible x?, because you would either A) stuff the electronics in there. or B) the thing would be huge!

[fawnheart2000]

Maybe about 25% larger than the bubble tape one in costume forum. I was thinking about mounting to a large washer for a heatsink, and having a filter between the led optics and the reflector to dim it a bit. See with only one led it doesn't light up some figures well, such as the upper parts of Ki-Adi-Mundi or the Toys R Us Emperor. I was thinking have two leds one in front and one just behind where the figure would stand. (Or if possible three equadistant from each other around the figure.) Yes this thing would suck batteries dry quickly, but since you would only turn it on for a few moments each time hopefully the heat and battery consumption wouldn't be too bad. I don't know maybe this is just a pipedream, then again owning a good lightsaber replica was a pipedream a few years ago.

[acerocket]

Your battery needs would be dependant on the number and type of LEDs you use. You are concerned about brightness so I would suggest the 1 watt royal blue emitter. Luxeon published specs say 350 ma and 3.42V. So if you connected them in series, you would need to add the voltage to find the correct total voltage. In this case, you would need 10.26V. To do this sized battery, you'd be looking at three Li-ion (11.1V) or 10 AA or AAA cells (12V). But, I happen to know that you can run the LEDs with less than the specified voltage. You are just going to run them at less then optimum brightness that way. You know it happens because LED sabers run on AA cells get dimmer as the battery pack runs out. If you want to do it the easiest way possible for three LEDs, then I would just use a 9V battery and go direct drive with no resistor. The LEDs will run but not at their brightest. As the battery drains, the light output will decrease also. Not sure how long a 9V battery would last though. Perhaps a couple of hours? If you can swing a larger/better power pack, then you can run the LEDs at a lower milliamp rating to decrease the brightness and select an appropriate resistor to run you LEDs at that current.

[Strydur]

Here is a great calculator to use for this.

http://metku.net/index.html?sect=vie...calc/index_eng