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 is from a 1967 documentation. It makes use of varicap and diode tunnel in addition to...
Author: Newton C. Braga Published:July 5, 2016 Formato:Book and e-Book Pages:...
This circuit is from an American publication of 1978. It can be assembled with modern transistors, since...