How a Doorbell Works

Doorbells are in just about every home across the U.S.

Doorbells are one of the most common greeting tools built into modern homes--allowing the homeowner to know that someone is at their door. They can come in various sounds, ranging from simple buzzes to elegant songs. Doorbells are relatively simple electrical devices and work on simple principles.

Appearance

The visible portion of a doorbell normally comes in a variety of designs based on the homeowner’s preference. It features a covering which contains a button in the center. The button is normally a circle, oval or rectangle. Pressing it inward will cause a short chain reaction that results in a sound made throughout the home, alerting the homeowner to someone’s presence at the door.

Voltage

All doorbells are electrical and therefore have a designated voltage under which they operate. Doorbells require very little electricity and operate on a low voltage. Many older types of doorbells only use 6 to 8 volts. Newer doorbells will normally operate on 12 to 14 volts. Bells, chimes and buzzers, which usually create louder and longer sound, will often operate on 16 volts.

Power Source

To produce the necessary voltage to operate a doorbell, a transformer is used. The installed transformer creates a lower voltage through the conversion of a 120 volt current, which is the standard within U.S. households.

Circuit

All doorbells operate off of a simple circuit system. Each doorbell has two very small wires that run to the transformer. One of the wires is interrupted by a push-button switch--which is connected to the button the person at the door presses. When the button gets pressed in all the way, it completes the circuit, which delivers the low voltage to the bell or chime unit.

Bell Unit

The bell unit operates off one to two pistons that are spring-loaded and slide in and out of an electromagnet. A voltage that is produced by the doorbell will charge the magnet, which moves the pistons against the springs. When the charge ends, the springs force the piston against the bell or chime, creating the doorbell sound.

References

• HomeTips: Doorbells: How They Work
• Explain That Stuff: Electric Doorbells