In the figure we have a simple way to produce tone in a piezoelectric transducer. The frequency depends on the capacitors and the supply can be done with voltages from 1.5 to 6 V.
This interesting control circuit was found in an Electronics Now from 1988. Through it we can...
This circuit causes neon lamps to flash randomly from a low voltage supply (1.5 to 3 V). The...
Any operational amplifier, like the 741, can be used on this oscillator whose frequency depends on R1...