help in our led design project - basic led application project

[kbags-xuece]

i really need help in our electronics1 final project.. we really had problems how to design a basic led application project. it is possible to use a 12V voltage source to make it work? we need to form the word ENGINEERING and in every letter has a measurement of 6in height and 4in width. basically in every letter almost 50 more leds are used.. how do we do it? what are the series or series parallel connections to be applied here..

help pls. thanks
 

[marcelino]

you could play with series circuit, the forward voltage should be known.

if i may, i will implement it in parallel to be sure. meaning individual resistor for each LED.

this link may help you : http://led.linear1.org/led.wiz

i suggest you should know exact forward voltage and for current so that you could design it properly. However, i simply compute it with Vf as 2V and If 10mA. Very rough yet very safe estimate yan. typically, LED have different forward voltage and current depending on the brand and model. It also differs depending on the color of LED. Different color means different chemical composition. I guess those generic LEDs that could be bought in your local electronic shops have 3V and 25mA, forwards voltage and forward current, respectively.

[marcelino]

look at these ;http://www.sparkfun.com/commerce/tutorial_info.php?tutorials_id=47&sipp=1&page=1

just an inspiration on the construction of the big LED ENGINEERING word! I like the construction using the Styrofoam adn covering it with translucent material. they used styrene. perhaps you may want to make use of ultrabright LEDs, medyo mahal lang kasi 10pesos yata ang isa nun.

[kbags-xuece]

thanks.. but i hve additional info to post here to further explain how this project must work.. what do u think must be the ideal voltage source for this kind of project? 36V?

[SpongeBob]

thanks.. but i hve additional info to post here to further explain how this project must work.. what do u think must be the ideal voltage source for this kind of project? 36V?

voltage depende sa koneksyon na gagawin, kung 50 LEDS in series, If=15mA, Vf=1.7 pwede rin 100 VDC basta lagyan ng 1 k ohms 1/2 watt na resistor at ingat kasi high voltage