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RSS > Help with some resistors, Newbie to Free Track looking for some help from the gurus

xxBLIZZxx	#1 08/07/2009 - 22h14 Top
Class : Apprenti Posts : 2 Registered on : 06/07/2009 Off line	Hey all, Im new around these parts and was hoping for a little help. Although I have already read a lot and seen the tool on the main page, I hope Im not the first person to look at the wizard there like a confused dog. Anyway I have (3) 5mm IR LEDs 1.2 forward voltage and 100mA forward current. I planned to run them on 2 standard (non-rechargeable AAs). I was hoping someone could tell me which resistors to pickup at my local radioshack. Thanks for any help.
benmeijer	#2 08/07/2009 - 23h02 Top
Class : Habitué Posts : 208 Registered on : 19/07/2008 Off line	For 2 X AA 1.5 battery = 3 V use 27 ohm resistors to power the leds with 70 mA For 1 x AA 1.5 battery (it's possible to use only one) use 4.3 ohm resistors to power the leds with 70 mA Resistors type E24 Carbon or Metalfilm 1/4 watt
xxBLIZZxx	#3 09/07/2009 - 01h51 Top
Class : Apprenti Posts : 2 Registered on : 06/07/2009 Off line	RS obviously doesnt have the selection it used to. They did carry a 22 Ohm 1/2 watt 5% tolerance resistor. Any chance I could get away with that?
benmeijer	#4 09/07/2009 - 09h07 Top
Class : Habitué Posts : 208 Registered on : 19/07/2008 Off line	xxBLIZZxx @ 09/07/2009 - 01h51 a dit: They did carry a 22 Ohm 1/2 watt 5% tolerance resistor. Any chance I could get away with that? Yes, using 22 ohm will power the led with 85 mA (your leds can have 100 mA max.) 1/2 watt resistor is no problem....

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