Music Generator Circuit Description
The first circuit shown here is configured to produce sounds imitating birds chirping . The circuit functioning can be understood with the following points:
Chirping Bird Sound Generator:
In a few of my previous posts, I discussed astable multivibrator (AMV) circuits and how these configurations are immensely versatile and provides wide application options. Here a couple of these AMVs are incorporated for creating the sound effects.
AMVs are basically oscillators which generate alternate high and low pulses. The frequency of these pulses is determined by the values of a few resistors and capacitors and also termed RC time constants.
In the present application the two AMVs are specified with the tasks of controlling the tone oscillations and switching oscillations respectively.
In the diagram the upper section defines the pitch of the tone while the lower design controls the length of the tone and its breaks.
Through a smart integration of a couple of resistors and a potentiometer the upper section is biased intermittently by the lower rate generator circuit, so that the tone generated by the upper section can be switched at a particular rate, shaping typical bird chirping effects. The pot may be varied for enhancing the tone so that it imitates the effect to near perfection. Another Pot VR2 is used for making the chirping rate faster or slower.
If the circuit is intended to be used as a door bell, the inclusion of the large capacitor 2000 µF becomes pretty handy. Once the bell push button is released, the capacitor allows the sound to persist for few seconds and gradually decays down instead of shutting off abruptly.
The generated tone is directly fed to a loudspeaker for the required reproduction.
Parrot Sound Generator:
A nice little electronic project in the form of a parrot voice generator circuit is illustrated here, which is especially suitable for new electronic enthusiasts as it hardly involves any complications.
Again the circuit is primarily configured as an audio oscillator having a “sweep" facility included. The facility enables the generated frequency to be automatically “swept" or altered across two set frequency limits.
Basically two output transformers are incorporated for creating frequencies responsible for the desired sound effects. However the, left hand side transformer and the transistor along with the associated components actually generate the parrot tone, the extreme right hand side transformer is used for stepping up the frequency potential so that the connected speaker at the secondary winding can be driven hard producing an amplified output.
Woodpecker Sound Generator
The circuit is a bit similar to the first circuit as it also includes a free running multivibrator circuit. The unit produces a “tick, tick" sound, resembling a wood pecker hitting a tree bark with its beak. The frequency of the “pecking" beats can be adjusted by the variable resistor for optimizing the sound effect as close as possible to its original counterpart.
Though it may not be a nature lover's preference, the circuit can be further adjusted and modified for generating motor boat throttling sound effects also, if desired.
Pressing the push button initiates the sound effect generations, which gradually dies down until the 2200 uF capacitor has completely discharged.
Images and Ideas By Swagatam