This flasher circuit consists of an astable multivibrator with the frequencies given by the capacitors. The circuit is from 1965 using light bulbs, but LEDs can be used. Power comes from 4 batteries.
This old fashioned amplifier can source some watts to a low impedance loudspeaker. The circuit...
This circuit is from a 1975 amateur radio manual. The components can be approximated to the...
This circuit receives the local stations of medium waves listened to in a piezoelectric capsule or...