Hi I am doing a project on High speed modulation of LED's and I was just wondering if anyone has a very simple circuit design for the this experiment.
I saw another circuit online (attached below) and I made it in the lab but it seems to be giving me wrong results. I am changing the frequency on the function generator gradually from 1Hz all the way up to 25 MHz. Channel one of the oscilloscope was attached to the input signal from the FG and channel two of the oscilloscope was attached to one leg of the LED to measure the output. Every time I changed the frequency on the function generator, I was measuring the phase shift between channel 1 and channel 2 of the oscilloscope and also their amplitudes. Also I noticed that, after around 800KHz on the function generator, the results just doesn't make sense at all. Any help would be appreciated of a very simple and basic circuit to modulate an LED. Thank you
I have shown this circuit to my supervisor and he said its too complicated for just modulating LED's and he would prefer a much simpler circuit.
I saw another circuit online (attached below) and I made it in the lab but it seems to be giving me wrong results. I am changing the frequency on the function generator gradually from 1Hz all the way up to 25 MHz. Channel one of the oscilloscope was attached to the input signal from the FG and channel two of the oscilloscope was attached to one leg of the LED to measure the output. Every time I changed the frequency on the function generator, I was measuring the phase shift between channel 1 and channel 2 of the oscilloscope and also their amplitudes. Also I noticed that, after around 800KHz on the function generator, the results just doesn't make sense at all. Any help would be appreciated of a very simple and basic circuit to modulate an LED. Thank you
I have shown this circuit to my supervisor and he said its too complicated for just modulating LED's and he would prefer a much simpler circuit.
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