Elits
Member level 4

hai all,
now i am build a dot matrix which its injected by audio. for the audio I use Fm modulation (carrier frequency = 50khz)and for the wave i choose square instead of sine. i connect the square audio to clock pin of CD4017(decade counter) and the output to every row of my dot matrix. so, the idea is every change of the square wave will change the row too (row scanning). But the effect of scanning influence the audio at receiver. There is new sound with high frequency
. When the output audio connect to one LED (without scanning), the audio at receiver it's OK. So how to overcome the scanning Effect. I used High pass filter (fc=33kHz in the front of receiver) and Lowpass Filter (fc= 15khz) at the end receiver.
thanks
Elits
now i am build a dot matrix which its injected by audio. for the audio I use Fm modulation (carrier frequency = 50khz)and for the wave i choose square instead of sine. i connect the square audio to clock pin of CD4017(decade counter) and the output to every row of my dot matrix. so, the idea is every change of the square wave will change the row too (row scanning). But the effect of scanning influence the audio at receiver. There is new sound with high frequency
thanks
Elits