FreeTrack Forum
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Hi Guys,
Sorry in advance, newbee inside  I have a stock of IR SFH 415T, so I would like to go ahead with 3 of them for building my system  This type of led is givne for 100mA. In this forum I found than if constructor say 100mA I should enter 70mA in the wizard to compute the resistor, but I'm not sure about this. So what do you recommend here ? In fact, if somebody could verify the specs I found for SFH415T that will be great too!  :950nm 100mA 1.3V (2.3V) With a 9V power supply, according to the wizard, resistor must be: For 70mA => 75 ohms 5% For 100mA => 51 Ohms 5% That's an "huge" difference!  what do you recommend ?Thanks in advance!  Loran |
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Class : Habitué Off line Www |
here is the specs for both siemen's and osram's SFH415t:
Peak Wavelength (m)=950n P(O)rad Min.(W)Rad. Out. Power=25m @I(F) (A) (Test Condition)=100m Spectral Bandwidth (m)=55n Half-Intensity Beam Angle(Deg)=34 t(resp) Max.(s) Response Time=500n I(F) Max. (A) Forward Current=100m V(F) Max.(V) Forward Voltage=1.3 @I(F) (A) (Test Condition)=100m V(R) Max.(V) Reverse Voltage=5 Semiconductor Material=GaAs Package=LED-2b You can and should infact input 50ma in the led wizard. Trust me, this low value will still work very well. It will make your battery last longer and put less wear on your led's That means your resistor value should be 100 to 102 ohms. I hope this helps  don't forget to sand down those tops, use a finger nail buffer to finish. Also, where did you find these led's? They are a rare breed now. well in my neck of the woods
The only way to fly!!!
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Class : Habitué Off line Www |
The only way to fly!!!
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Hi!
Many thanks for you answer  I mean a 9v battery. I saw a lot of post and reply from you around here, so I will follow your recommendations for sure! Those leds came from a friend. He found that in a store we have here (Lyon, France). Great ! I hope to finish my system pretty soon now!  Thanks again ! Loran |
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Class : Habitué Off line Www |
No problem, I'm glad I could help. Je desire savoir comment il ressemble, quand il est fini.
Marcus
The only way to fly!!!
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