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.
The circuit shown in the figure can be used to detect the operation of infrared sources whose...
This circuit is from a factory manual from the 80s. The circuit can be implemented with more...
This circuit for the logic control of the 555 in a power supply was found in the October 1989...