This 555-based circuit was found in the August 1976 issue of Radio Electronics magazine. The tone frequencies are provided by the capacitors connected to the 555 IC.
In the figure we have a circuit in which two moving bar/dot indicators are connected together to...
This simple unregulated half-wave font was found in old American documentation. The diode is...
This simple radio for listening to a headphone with two CK722 transistors was found in Radio...