This project shows you how to build a robot voice generator with IC HT8950, a powerful voice modulating IC. The circuit has Robot function, Vibrato function and 7-step level shifting pitch. The construction is extremely simple and the unit is very small.
The project has four buttons set for robot, vibrato, down pitch, up pitch. At the output it has an audio amplifier LM386. You can make many combinations with modulated and unmodulated audio by mixing potentiometer P2 and P3. Internal frequency and thereby the robot sound frequency can be set via Potentiometer P4. Potentiometer P5 set the vibrato frequency of the robot sound. To run the circuit, a 2.4 to 4.0 V power supply is needed. Download : robot voice circuit.