This 1967 Philips circuit recognizes a light signal (visible or infrared) modulated by tone. The circuit makes use of components of the time that are equivalent to the current BCs.
This circuit detects traffic problems on a miniature railway by triggering an alarm. The circuit was...
When establishing the voltage at the input of this regulator, the output voltage rises smoothly until...
This circuit was found in a Motorola documentation from 1975. Modern equivalent transistors such...