Door Bell circuit

 

Introduction

Door Bell is an indispensable item for every household. Varieties of doorbell circuit designs are available in the market. You can procure it readymade or you can assemble it of your own by procuring the required components. Simple transistorized to IC based doorbells are on the market. They can be purchased and just fix it in the household. 

But hobbyists would like to build a simple cost effective doorbell of their own as an electronics project.  The door bell described here requires very few components and works on just two transistors. The circuit design presented here is a favourite one among hobbyists and students who love to build electronics projects. 

The circuit schematic

Please go through the circuit design and observe how simple it is in its design and working. Two NPN Silicon transistors are employed and the audio output sound is derived from a buzzer. The buzzer sound do not scare anybody in the house. One can get sweet music producing buzzer can be procured and employed in the place of conventional buzzers. 

Please remember that input AC voltage is 6 to 9 V and not 230 V. Low voltage AC can be fed from the secondary of a power transformer which is not shown in this circuit diagram. Whenever bel switch SW is pressed buzzer gives an audio sound. Hence SW should be a bell push switch. 

Parts List

Assembling 

The circuit can be neatly assembled using the readymade PCB design given here. The circuit can be housed in a plastic box and can be fixed conveniently on the wall. Wiring should be done accordingly to enable the bell push switch outside the door. 

To sum up

Build this low-cost doorbell with ease and give your comments for the benefit of all.