Sweep generator LM324
A sweep generator is an oscillator that changes its frequency with time from low to high ranges. It "sweeps" through a certain frequency range. The sweep generator we're going to make in this project "sweeps" its frequency by changing the VCO input voltage slowly, making use of the CR charging/ discharging function.
When you finish wiring up the circuit, rotate the control volume fully counterclockwise and turn power ON.
Then press S1 for 1 - 2 seconds and release it.
Through the earphone, you can hear the frequency sweeping from low to high ranges. If you don't, try rotating the control volume clockwise slowly, until you hear a sound through the earphone.
You can also hear the frequency sweeping in different ways by changing the setting of the control volume.
Can you see why?