This 4093 IC continuity tester was found in the November 1986 Radio Electronics magazine. The circuit powers a ceramic buzzer with a frequency setting.
This ultra-low power metronome was found in a 1991 documentation. The output transistor is general...
Very rapid brightness changes or flares that occur on the sun can be detected with this circuit that...
This oscillator circuit with two transistors is from a 1965 documentation. The circuit is of the...