Noisy Strobe Light
There's no reason why we can't use both a LED and the Speaker with an oscillator ... so we'll do just that in this Project.
This circuit flashes the LED and makes a sound from the Speaker each time the circuit oscillates. You'll find the sound to be similar to that of a machine gun. Just press the Key when you finish the wiring connections-you'll see and hear.
As you can see from the schematic, oscillation is controlled by the charging and discharging of the 10 uF capacitor. And the capacitors charging and discharging is controlled by the 22K resistor.
Look over your notes ... what effect do you think changing the values of those two parts would have on this circuit? Try it and see.