Re: TI-H: Re: LZ: Backlighting
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Adam S. Nickerson wrote:
<<<snipped about 10 pages.. :) >>>
> With LEDs how can you tell how much power they need to run, and whether
> or not they should be placed in series with a resistor so they won't
> burn out?
If you got the LED at Radio Shack, it comes taped to a card that tells
you what voltage the LED wants and how much current it wants. If you
didn't get it at RS, a diode checker will tell you the voltage drop
across the LED-this is the voltage the LED wants to run on. Then you
apply Ohm's law: R=(V1-V2)/I2. R2 is the value of the current limiting
resistor (in ohms), V1 is the supply voltage, V2 is the LED voltage
(drop), and I2 is the LED current. Any questions?
<pre>
--
Greg Hill
http://braves.bhs.davis.k12.ut.us/
ghill@lab.tech.bhs.davis.k12.ut.us
greg_hill@email.state.ut.us
</pre>
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