# led question



## SCYTZOH (Jun 25, 2002)

i dont know if this is a noob question or not but here goes: i bought a led setup ment for a car from a liqidator place. its really cool it is as follows:
(1)cental hub thinngy with several slot plugs of different sizes. only (2 )of which are used by the strings of leds that came with it. the "Hub" contains only plugs no resistors or anything.
the (2) strings that plug in to the hub each have the following 4) puck shaped clear cases each of which contain (6) leds. 2 red 2 blue and 2 green. board also containing (3)resistors.
im assumming one for each colour. the colour code on these resistors is green blue brown.

this is all that came with it no adapter nothing and being a liqudated item i got for cheap and as is

normaly i would assume 12 volts being from a car but i know some car accesories have adaptors knocking it down to whatever volts. my question is can any tell what that voltage is i need by lookin on the resistor codesand the oth


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## TheMatt (May 9, 2006)

Generally things like LEDs will have a maximum rated current that you can put through them. You then take whatever voltage you are given (provided its DC voltage) and use Ohm's law to determine the proper resistance needed to achieve that current flow or lower, remembering to take into account resistor tolerances. As always, test your power source and any resistors you are using to make sure they are within range.

If the resistors come with the LED package, then it should tell you either the voltage it was designed to work with or the maximum amperage the LEDs can handle. In either case, you can again use Ohm's law to determine the necessary voltage.

Ohm's law: E/IR


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## jem_maccas13 (Nov 4, 2007)

i have a question,,why my CPU's red light is always OFF?? what is the reason why my CPU's red light if always off? and my computer is stop working or being stock??...plssss help....


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## TheMatt (May 9, 2006)

jem_maccas13 said:


> i have a question,,why my CPU's red light is always OFF?? what is the reason why my CPU's red light if always off? and my computer is stop working or being stock??...plssss help....


You are going to have to start your own thread for that.


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