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Do you need a resistor to hook up an IR led if you r using an AA battery? Answered


2 Replies

Sandisk1duoBest Answer (author)2009-02-07

do you know how much voltage/amperage it needs?

if so go here and fill in all the appropriate fields

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11010010110 (author)2009-02-07

use this wizard to find the resistor

a resistance of 2 AA batteries is about . .
0.5 ohm or less - rechargeables (but they are 1.2 and not 1.5 V)
0.5 - 2 ohm - energizer
2 - 5 ohm - duraell
5 - 10 ohm - most batteries

if its significat when compared to the suggested resistor - subtract it

for example if it suggests 20 ohm resistor and you use 2 normal AAs (not ener / dura) you need about 10 ohm resistor only. if it suggests 10 ohm resistor or less then you dont need one at all (the batteries have enough resistance themselfes)

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