This power step drains just 3.5 mA from the battery and can provide good playback on a 4-ohm speaker. The circuit is from an 80's documentation.
This 10-transistor radio was found in Radio Electronics magazine from December 1964. The...
This oscillator uses one of the four ports of a 74C14 integrated circuit and can generate 100 kHz...
This simple humidity alarm circuit includes a timed warning oscillator whose time is set to R4....