This 1 kHz circuit was found in American documentation from the 90s. The original operational amplifier consists of a double 741 at the time. The power supply must be symmetrical.
This interesting circuit found in a European publication from the 1990s eliminates the voice that...
This simple circuit that interrupts the supply of a 12 V load in the event of an overvoltage was found in...
The radio presented was found in a 1980 documentation. It consists of 3 stages: the tuning circuit...