signal conversion

[mitesh]

i am working on a signal converter and pulse generator.

can a sound signal be converted into a dc pulse that can use in a pulse counter circuit?

 

[Kevin Weddle]

A pulse counter will continue to count the pulses indefinitely. Let's say you have a high frequency and the pulses you count are many for a certain duration. So you set the duration with the enable line. You still have a bunch of frequencies that need to be separated so that you have one frequency at the input to the counter. Use a bandpass filter. Amplify the frequency until it becomes a pulse. Now you can count the pulses and determine that you have that frequency. If it's not there, then you won't have any pulses to count. Do this with each frequency you want to make sure is there.

 

[mitesh]

sir, after passing the signal through low pass signal and amplifting it is it not necessory to convert it into dc pulse? can a frequency can be used in pulse counter?
plz provide me more details over it.

 

[Kevin Weddle]

A bandpass is not a low pass filter. The amplifier will turn the triangle shaped wave of the audio, of a single frequency, into a square wave. Then the pulses can be counted over a given duration set by the enable line. 5 pulses in .5s will give you a frequency. 6 pulses in a given .5s means the filter did not select the correct frequency. 0 pulses in .5s means the frequency is not in the audio. The purpose of this exercise is to know that the audio contains the frequency you have selected.