Music Box Circuit
Created: Dec 07, 2014
No description available.
This circuit produces 10 different tones and by selecting suitable values to change the voltage on pin 5, the result can be quite pleasing. Note: the two unused outputs of the 4017 produce a tone equal to that produced by the 555 when pin 5 has no external control voltage.
The 555 timer is used as clock generator for the 4017 decade counter.When the left 555 IC clock rate is varied, the speed of the 74HC4017D output sequence are changed proportionately which determines the musical sounds of the box. The above arrangement in conjunction with the capacitor C2, forces the timer to oscillate at a specific predetermined frequency. Whenever a 4017 output is activated, the right hand side 555 oscillates at a frequency prefixed by the set R (of the outputs of 4017), in conjunction with R1 and C2. Once the entire sequences of the 4017 outputs are implemented, the IC is reset and process is repeated.
As can be seen, the project enables us to experience and achieve a sequenced set of notes as per the liking of the user. Experimenting with the values of the resistors in series with the diodes may be a good idea to start with. You can also experiment and change the spaces and location of the "silences", by randomly leaving or choosing from the other pins of the 4017 outputs. The music box circuit is powered with 6V battery.