Welcome to the N1IR Electronics Website. Totally off the cuff, one take, unrehearsed video projects for anyone interested in amateur radio, electronic design, makers, hardware hackers and science.

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Training the hand and mind since 1982.

Tuesday, January 29, 2013

AM over Fiber Optics

Here is a recent experiment I had my 12th Grade class do. It a simple circuit that modulated audio over fiber optic cable. We learned about wavelengths in the infra-red spectrum, how to bias and modulate an LED (AM Mode), how bias the photo transistor and pull the audio off and of course micro-bending attenuation

Parts List:
IF-D92 Digi-Key Part Number FB121-ND
IF-E91A Digi-Key Part Number FB118-ND
IF-C-E1000 Digi-Key Part Number FB140-1-ND
(2) 10K resistor
(2) 1-22 uF Cap (not critical) more bass with the larger cap
(3) 9V Batteries
3.5mm Plug
Audio amp or amplifier PC Speakers
Dollar Store Radio
8 Ohm Resistor (Dollar Store Radio only)