how to generate the signal

[lhlbluesky]

i want to generate the following waveform, the first waveform is the input, the second waveform is the output, that is, the output waveform changes state (0 to 1, or 1 to 0)when the input falls down to the low threshold. it is very strange.
i'm confused, what circuit can realize the function? please help me. thanks all.

 

[barry]

1) Note that the bottom waveform is 1/2 the frequency of the input.
2) Apply the input waveform to a comparator
3) The output of the comparator drives the clock input of a flip-flop.
4) Did I just do your homework for you?

This solution would not create EXACTLY the output shown. IF you really need output to switch at the inflection point of the input (where the slope changes from negative to positive), you would need to use something fancier, like a differentiator.

 

[lhlbluesky]

thanks barry. but i want to know, how to realize a differentiator, and how to realize the function using a differentiator? can you explain more clearly? or give me some papers? thanks.

or any other ideas?

 

[barry]

Search the web for opamp differentiator, there should be plenty of examples