This circuit is from an American documentation from 1975. The circuit uses components of the time which can be replaced by modern equivalents. The coupler is homemade with a lamp and a photocell.
We found this complementary simetry configuration in a1980s documentation. Transistors, which are...
This circuit was obtained from the May 1971 issue of Radio Electronics magazine and is intended for...
This circuit acts as a VU-meter when connected at the output of any audio amplifier, triggering a...