With this circuit it is possible to receive and send audio signals simultaneously over the same telephone line. The circuit was found in an Elektor from the 90s. The power supply is symmetrical.
This oscillator circuit for sinusoidal audio signals with operational 741 requires a symmetrical power...
Found in a 1974 Radio Shack documentation. This circuit must have a connection to the ground of...
This sensitive circuit detects the live pole of a power grid or outlet. The circuit makes use of a high...