Author Topic: help: ir pen  (Read 5185 times)

Offline perkdog

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on: March 26, 2008, 12:22:18 PM
i need help my local radio shack only has a led that is 1.2v but it says on the package that the maximum voltage is 1.6v i am confused. i only want to to use a single 1.5v battery but do i need any Resistors if so how do i calculate the ones i need.
thanks     



Offline UndCon

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Reply #1 on: March 26, 2008, 05:04:51 PM
If I were you I would go for a rechargeable AA or AAA battery

they are 1.2Volts



Offline admonkey

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Reply #2 on: March 31, 2008, 01:41:58 AM
http://ledcalc.com is a sweet site that allows you to input the voltage of your power source and LED and it will calculate the resistor value needed.

and I think my AA batteries are actually 1.5V. but either way, for the materials you listed above, you will not need a resistor if you use AA or AAA

resistor values come in to be important if you try to mod an existing LED light device. considering most visible light LEDs are rated for 3V, the power supplies they have will probably blow out your IR LED instantly if connected directly without a resistor.
« Last Edit: March 31, 2008, 01:47:31 AM by admonkey »



Offline UndCon

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Reply #3 on: March 31, 2008, 06:32:54 AM
If your batteries are rechargable then they are 1.2 volts - and if they are not you get 1.5 volts



Offline imarzouka

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Reply #4 on: April 02, 2008, 03:20:10 AM
Use 1.2V as the typical voltage and use this calculator http://ledcalculator.net for the resistor values.

Good luck :)