This old 4-channel circuit was found in the December 1994 Electronics Now magazine. The circuit uses a 556 as a modulator. Note the code programming key.
This circuit uses a transistor as noise source and a 741 IC as amplifier, sourcing a high...
This simple circuit detects when a conductive liquid reaches the sensors. The circuit has no...
With this circuit it is possible to raise the characteristics of a transistor by checking its gain...