This source for 50 W amplifiers per channel was found in 1967 Delco documentation. Transistors are from that time, difficult to obtain today.
This simple alarm circuit was found in a 1998 documentation. When the sensors are activated, the...
This circuit was found in an old American documentation. The integrated circuit used is uncommon...
Found in a 90s Electronic Design, this suggestion to have a higher voltage in a fixed regulator...