This is a project of a ding dong door bell circuit using 555 IC. In the previous article we have discussed about a simple doorbell circuit using UM66 IC which is a CMOS three terminal melody IC. The circuit mentioned here is using NE555 IC and few other components to create doorbell sound.
The frequency of sound can be controlled with 5.6k and 10k resistors. The transistor 9013 is used to amplify the output of IC to drive an 8 ohms speaker. You can also use substitute transistor in the place of 9013. The circuit will produce ding dong bell sound by pressing the switch near the 1N41418 diodes. The operating voltage of the circuit is 4.5 volt DC.