This circuit that can amplify signals from 0 to 30 MHz was found in a 90s Popular Electronics. Transistors admit current equivalents. The input impedance is high.
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....