Simulating bird call circuit schematic diagram

The integrated circuit has 5 lead-out points 1, 2, 3, 4, and 5. Their functions are:

1——Power supply positive pole

2——Trigger

3 - Original audio output

4——Amplify audio output

5——Power supply negative pole

The function of capacitor C:

Capacitor C is a ceramic capacitor with a capacitance of 0.01 microfarads. The "103" in the brackets in the picture is another representation method, which means "10" followed by three zeros, which is "10000". This representation method The default unit is "picofarad"; 1 microfarad = 1,000,000 picofarads. So, "0.01" microfarads = "103" picofarads.

C is used to prevent the self-excitation of the triode BG (9014). Sometimes, the circuit is made completely correctly, but the speaker is silent. At that time, just add capacitor C. This is because the amplification of the transistor is too large and produces self-excitation, which is suppressed instead. Therefore, when the magnification of BG (9014) is small, C is not needed.