Found in an Electronics Now from the 90s this mixer has several inputs. The integrated circuit can still be found easy and the power supply need not be symmetrical.
This alarm does not interrupt its operation when the power is cut. A battery is kept at a constant...
The sophisticated signal tracker/follower with a JFET and integrated circuit 741 was found in a...
This circuit, found in a publication from the 1970s, produces a 1 Hz sinusoidal signal....