A single integrated circuit is the basis of this oscillator that can deliver a powerful audio signal directly to a speaker. We can even use it as a basis for alarms, warning systems or even for telegraphy, replacing S1 with a handler. The frequency may be modified through capacitors C1, C2 and C3.
9 V power can be obtained from either power supply or batteries, as a small 9 V battery would quickly deplete given the consumption, close to 1 W. The speaker should be good at performance and installed in a small speaker for sound with higher intensity.
In figure 1 we have the complete diagram of the oscillator and in figure 2 a printed circuit board for its assembly.
Material list
CI-1 - LM380 - Integrated Circuit
S1 - Single Switch
B1 - 9 V- power source or batteries
FTE - 8 ohm x 10 cm - speaker
R1, R2, R3 - 12k ohm x 1/8 W - resistors - brown, red, orange
C1, C2, C3 -100 nF - Ceramic or Polyester Capacitors
C4 - 220 uF x 12 - Electrolytic Capacitor
C5 - 47 uF x 12 V or more - Electrolytic Capacitor
Miscellaneous: printed circuit board, power supply, wires, solder, etc.
