Hi! Sometimes earlier I posted a thread titled "pulse time filter". I had to get rid off pulses which have a pulse width less than 2ms.So 3iMaJ answered like below.
"What I said if you read my post is that the way you describe doing it is far too complicated, and I suggested using a low pass filter and a schmitt trigger. I simulated the idea in matlab and I got rid of the 2ms pulse by widening the 5ms pulse by 80 microseconds. If thats not with in the tolerance, you could sharpen the roll off on the filter, I put the stopband at 300 hz, it could be lessened, but the filter would get longer.
The new schematic would be LPF > schmitt trigger, everything else is unnecessary. Essentially what this idea does is filters out the main lobe of the sinc function created by the 5ms pulse, and then reconditions the signal because the filter also wiped out the tails of the sinc function for the 5ms pulse (and we need those to have a pulse), so I used the schmitt trigger to put them back in. The consequence of doing it this way is you slightly narrow the main lobe of the sinc function (that means widening the pulse) by 80 microseconds. Thats a small price to pay I think."
At that time I tried it with hardware but it dint work. So I simulated it (nw only I got an orcad s/w cd) pspice, and found some funny out puts.
So? (really I'm a telecommunication guy. I know theoretical electronics and nw trying to use it practically with your help. This site really wonderful people like me. thanks for these tronic brains)
"What I said if you read my post is that the way you describe doing it is far too complicated, and I suggested using a low pass filter and a schmitt trigger. I simulated the idea in matlab and I got rid of the 2ms pulse by widening the 5ms pulse by 80 microseconds. If thats not with in the tolerance, you could sharpen the roll off on the filter, I put the stopband at 300 hz, it could be lessened, but the filter would get longer.
The new schematic would be LPF > schmitt trigger, everything else is unnecessary. Essentially what this idea does is filters out the main lobe of the sinc function created by the 5ms pulse, and then reconditions the signal because the filter also wiped out the tails of the sinc function for the 5ms pulse (and we need those to have a pulse), so I used the schmitt trigger to put them back in. The consequence of doing it this way is you slightly narrow the main lobe of the sinc function (that means widening the pulse) by 80 microseconds. Thats a small price to pay I think."
At that time I tried it with hardware but it dint work. So I simulated it (nw only I got an orcad s/w cd) pspice, and found some funny out puts.
So? (really I'm a telecommunication guy. I know theoretical electronics and nw trying to use it practically with your help. This site really wonderful people like me. thanks for these tronic brains)
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