This simple continuity tester consists of an oscillator found in the 1983 Electronics Experimenter Special projects magazine. The circuit is powered by a single battery.
Found elsewhere in this section, this circuit is from the April 1971 Radio Electronics magazine. Note...
With this circuit, a relay can be activated from an alternating signal with frequency up to a few...
The sound of this experimental musical instrument is produced by the movement of the hand in front...