This simple circuit was found in a Japanese magazine in 1967. The circuit is listening on a headset and the coil is 50 + 50 turns of wire 28 or thinner on a ferrite rod.
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...