Mains Trigger Musical Door bell

Mains Trigger Musical Door bell

Various mains and battery operated doorbell project is already published in Now, here is a unique project in the series of doorbell by Dreamlover technology, using both mains and battery. The doorbell published here used mains for only trigger and rest work in battery.

The circuit of mains trigger musical doorbell is fabricated around musical IC UM3482 followed by a transistor and a diode and some passive components. The ac mains supply is given to trigger pin 4 of IC1 through resistor R1 and R2 and diode D1. Resistor R4 is used to block unwanted trigger.

mains trigger musical door bell


Resistors (all ¼-watt, ± 5% Carbon)

R1 = 220 KΩ

R2 = 33 KΩ

R3 = 22 KΩ

R4, R5 = 100 KΩ


C1 = 33 pF


IC1 = UM3482 (Music IC)

T1 = BC147

D1 = 1N4007


SW1 = Push – To – On switch

LS1 = 8 Ω loudspeaker