resurgence2012
Junior Member level 2
Hi
I have been working on a project to demonstrate a measurement of the speed of light using infrared LED and detector.
I have used an avalanche transistor to produce short(is) (400 ns) pulses and at the moment have a circuit using a high speed IR detector diode and amp AD4001.
The AD4001 is giving me a maximum of about 200 mv when the emitter and detector are very close. In order to achieve a satisfactory result I need the emitter and detector at least 30 meters apart. At this distance it is well nigh impossible to get more than about 1 or 2 mv on the scope. So I want to use a really simple single (preferably) transistor to amplify the signal. Any suggestions please about the type of amp to use? I am considering the simplest of all 2n222 transistor in a common emitter mode, but not sure how I should bias it. I am a beginner (relatively), so please accept my apologies for asking such a basic question. Cheers
I have been working on a project to demonstrate a measurement of the speed of light using infrared LED and detector.
I have used an avalanche transistor to produce short(is) (400 ns) pulses and at the moment have a circuit using a high speed IR detector diode and amp AD4001.
The AD4001 is giving me a maximum of about 200 mv when the emitter and detector are very close. In order to achieve a satisfactory result I need the emitter and detector at least 30 meters apart. At this distance it is well nigh impossible to get more than about 1 or 2 mv on the scope. So I want to use a really simple single (preferably) transistor to amplify the signal. Any suggestions please about the type of amp to use? I am considering the simplest of all 2n222 transistor in a common emitter mode, but not sure how I should bias it. I am a beginner (relatively), so please accept my apologies for asking such a basic question. Cheers