This approach alarm circuit was found in the September 1970 Radio Electronics issue. The 1 mH coil is wound on a ferrite rod. The relay is 12 V sensitive.
The circuit shown bellow is na áudio amplifier using Darlington transistor in a complementary...
Indicated for automotive use, this circuit was found in a Popular Electronics from the 90s. The...
This TTL circuit was found in an American documentation from the 80s. The components are common in the...