Using a 74123 TTL this circuit was found in the Radio Elecronics magazine of June 1975. The power supply must be 5 V. The capacitor determines the activation time.
We found this circuit in a Mullard manual from 1960. The transistor is a phototransistor of the...
The circuit that gave rise to this configuration was found in a magazine of the 1980s with the...
This oscillator with FET was found in Popular Electronics from the 90s. This traditional...