This circuit controls the passage of the signal from one speaker to another. The potentiometers must be of wire 50 to 100 ohms with dissipation according to the power of the sound system.
This ouput push-pull stage using bipolar transistors was found in a publication of the year 1968....
This alarm circuit was found in a 2004 documentation. The circuit searches for open NC sensors....
This variable bandpass filter was found in an American 1980s documentation. The power supply must be...