This circuit that we found in a 1990 documentation uses an LED as a sensor. The operational amplifier is equivalent to the 741 and the trigger adjustment is made in the potentiometer.
This circuit shows how to use flip-flops in a SIPO circuit with serial input and parallel output....
This circuit was found in the National Semiconductor Linear Applications Handbook, published in...
This circuit is from an 80's technical newsletter. The circuit can use any general purpose...