Indicated by Texas Instruments, this 1968 circuit measures the duration of a light pulse captured by a phototransistor. Equivalent phototransistors and transistors may be used.
This counter performs the same function as the 4020, but includes an internal oscillator. The...
This circuit was obtained in a Popular Electronics of the 90s. It against a kitchen hood based on...
This circuit is from a 1980s Signetics documentation. The circuit separates the modulation signal from a...