This 2005 Linear Technology circuit has separate outputs for monitoring the charge and discharge of a battery. Formulas next to the diagram let you calculate the components.
This simple metronome, from 1985 documentation uses only transistors and has two settings. For...
This circuit is suitable for modulating AM transmitters. The circuit is from a 1977 radio amateur...
This flasher was found in an old Hands On, but uses common components. The optocoupler can be...