In the figure we have 3 oscillators with logic gates that can be triggered by external logic signals. The circuits were found in the Radio Electronics magazine of April 1987.
When a pulse of light reaches the sensor [a CDs cell or LDR] the flip-flop changes its state....
This circuit is an impedance adapter. The circuit is from a Radio Electronics from April 1966. The...
This circuit was obtained in an old American documentation serving only for general purpose NPN...