Sound effects generator


Posted on Aug 21, 2012

This circuit can generate a European police-car siren, bird noises, spaceship sounds, etc. In addition, it can be put to use as a doorbell, an alarm, etc. The circuit consists of four parts: a binary counter, a D/A converter, a VCO, and an audio output amplifier. The initial frequency of oscillation is determined by potentiometer Rll. The VCO first oscillates at a relatively low frequency, and gradually picks up speed as the control voltage supplied by the D/A converter increases.


Sound effects generator
Click here to download the full size of the above Circuit.

The D/A converter is the group of resistors R1-R8. When none of ICl's outputs is active, little current will flow into the base of Ql, so the VCO's control voltage will be low. As more and more counter outputs become active, base cutrent increases,and thereby so does the VCO's frequency of oscillation. The VCO itself is composed of IC2-a, IC2-b, Ql, and the timing network comprisingD1-D4, Cl, RIO, and Rll. The buffer amplifier is made up of the four remaining gates from IC2, all wired in parallel.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

wireless FM bug
Negative Voltage Generator Schematic
20Db-audio-booster
Current-monitor-and-alarm
Variable-Voltage Reference Source
A Balanced Output Board For The Stereo DAC
Advances in Measurement & Sensor Tech
5v 1a power supply using lm2575
A potentially novel pre-amp for electret mic capsules which have their internal FETs Drain and Source connections available separately
Self-powered Fast Battery-Tester
12kHz IF oscillator circuit diagram



Top