The musical 16 Tune musical doorbell circuit diagram described in this article produces a different musical tune each time the bell push button is pressed. The bell produces a total of 16 tunes which follows successively.
The circuit is based on a CIC4822 LSI read only memory chip which contains a complete marked ROM, envelop, preamp etc., and requires just four external components besides the IC. The two resistors and the capacitor complete the oscillator circuitry and set the frequency. The transistor provides amplification.
The can work off voltages up to 5 volts. It draws only around 500 uA quiescent current and needs no on/off switch.
The complete circuits would build up into a module small enough to fit into virtually any type of enclosure.
Doorbell circuit diagram:
Components for Doorbell Circuits:
Semiconductors
IC 4822
Q1 2N3904
Resistors
R1 10k
R2 100k
Capacitors
C1 47pF
Miscellaneous
LS 8 ohms 0.5 watt speaker
IC socket
S1 push button
PCB
Batteries (3 x 1.5 volts)
Solder
etc.
