musical doorbell system
musical doorbell system:
the doorbell system is basically used in home.my project is in this doorbell system is used as musically here we use one IC(UM 3481 or UM 3482,UM 3483,UM 3484). this IC is having 16 terminals.we use one speaker and one diode(IN 4007),push switch,one capacitor(33p),two resistor(100k,470 ohm) and one npn transistor(AC 187).this is main components for this musical doorbell system project.
in this system we use only 3V DC supply.the input voltage is applied to the diode(IN 4007) and the output terminal of the diode is connected to the push switch and another terminal of the push switch is connected to the 4th pin of the IC.the 2,3,16th pin is connected to the positive DC power supply.the 9,12th pin is sorted.the 13th pin is connected to 33p capacitor.the 14th pin is connected to the 100k resistor.the another terminal of the capacitor and resistor is connected to 15th terminal of the IC.the pin number 5,6,7,8 is connected with negative terminal of the DC power supply.the 11th pin is connected with 470 ohm resistor.the other terminal of the resistor is connected with the base terminal of the transistor.the collector terminal is connected with the speaker and emitter terminal is connected with negative terminal of the power supply.the other terminal of the speaker is connected with positive terminal of the DC power supply.it is the process of musical doorbell system.when switch on the power supply the doorbell is ringing as musically.it the musical doorbell system.