Hi,
Thanks foy your replies. Food for thought.
Yes, the waveform shown is the carrier wave for another square-wave frequency of 500 - 2.5KHz. So the total signal consists of an alternating polarity LF square wave, +/-12V, with PRF user variable from 0.5Hz to 10Hz, pulse width 10 to 15mS, mixed with an AF square wave signal, amplitude 12V. The desire is to introduce a variable (OV) delay of several milliseconds as the falling edge of the carrier wave hits 0V, befor it falls to -12V. Similarly, to create an equal delay as the rising edge at the end of the negatve pulse hits 0V, so delaying the next positive pulse.