This circuit was found in a 1964 Electronic Design. It generates opposite phase signals from an input signal. Modern equivalent transistors can be used in the same configuration.
This powerful amplifier was part of commercial sound circuits from the 90s. The integrated circuit...
This circuit generates a control tone that serves to adjust amplifiers, check audio cables. The...
This circuit locks when the sensors are opened. The relay can be 6 or 12 V depending on the power...