The movement of the LEDs in this circuit mimics the back-and-forth movement of a pendulum, making it suitable for clock projects. The circuit is from a Radio Electronics magazine from May 1978.
This simple field strength meter was found in a 1967 documentation. The transistor is germanium, and the...
Using a CMOS 4001, this circuit provides frequency readings on an analog instrument. The idea of...
This circuit that emits siren sound can be used in a fire alarm. We found it in an old American...