Re: TI-H: Battery question
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Re: TI-H: Battery question
>> >I'm using 3 LEDs, each which require about 2V to light up. I'm
>> >connecting them in a parallel circuit, something like you see here:
>
>> You can hook it up directly to the batteries, but you will need to add
>>
>> a series resistor otherwise you'll blow out the LEDs. The batteries
>> Which comes out to about 286 ohms for 3 such LEDs connected in
>> parallel.
>
> I think he would be better off putting the leds in series, they
>propably would need any
> resistor then, and he would get less battery drain.
Being nonlinear devices, not adding a resistor is a *bad* idea no
matter what. If an LED has a Vf of 1.7 volts, but you attempt to put
2 volts on it, the current will go exponential and you'll blow the
LED. The resistor effectively "eats up" any extra voltage (not
really, but you can think of it that way).
So if you have 3 LEDs in series all with Vf of 2 volts and you have a
6 volt source, it "may" still be okay but the resistor will insure it.
-Mel
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