Doorbell Types

A doorbell is a signalling device comprising a transformer, chime and a push button. It is a security device that signals us with the presence of a visitor. When a visitor presses the push button, the chime rings inside the house to inform you that someone is around.

In 1817, a Scottish inventor, William Murdoch, invented the first mechanized doorbell that operates on a system of pipes and compressed air.

As technology improved, Joseph Henry invented an electric doorbell in 1831. These modern doorbells use a push button to work, they also use intercoms and video cameras to increase security.

Types of doorbell

There are three basic types of doorbells: the wired, wireless, and smart doorbells.

Wired doorbells

In a wired system, the wiring starts from the press button at the front door, connects to the transformer, and then the buzzer, or chime.

Related post: How to wire a doorbell.

When you press the push button, it closes the circuit. This allows current to flow into the electromagnetic system of the bell. The magnetic field produced by the electromagnet causes the metallic bars in the bell to strike, producing the “ding dong” sound you hear.

But for a bell to work properly, it needs a transformer. The transformer steps down the household current of 120 volts to about 8 to 20 volts required by a doorbell.

Similar post: How to find a doorbell transformer.

wired doorbell

Wireless doorbells

A wireless doorbell doesn’t need a wiring system to work, rather a press button and a buzzer.

While it saves you the expense of wiring the doorbell, it also has an inbuilt battery that may not last. The push-button has an inbuilt radio transmitter powered by a battery which, when pressed, sends a radio signal to the receiver unit usually plugged into a wall outlet in the house.

Once the receiver unit detects the signal, it plays a “dig-dong” sound via a loudspeaker.

You can also install a wireless doorbell application on your phone to monitor your home.

Smart doorbells

Since the emergence of the internet, several internet-connected doorbells known as smart doorbells have evolved.

Popular among them includes:

  • Ring doorbell
  • Google ‘Hello’
  • Skybell
  • Nest lab doorbell
  • Arlo video doorbell, etc.

The smart bells usually installed at the front door comprise a press button, HD camera, passive infrared sensor, and Wi-Fi electronics.

When the smart bell senses motion or pressed by a visitor, it signals the paired smartphone or other electronic device.

When the user receives a signal from the visitor, he sees the video coverage showing the visitor at the door, and they can have an audio conversation.

The recorded video is usually stored in the internet cloud and can be retrieved even if the smart bell spoiled or was stolen.


1. Are doorbell transformers AC or DC?

Doorbell transformers and all other forms of transformers use alternating currents. Transformers don’t use direct current because they are direct, stable, and cannot produce current. There must be a relative motion between a conductor and the magnet to produce the current.

Read the working principle of an electrical transformer here.

2. Are doorbell wires dangerous?

Doorbell wires are of low voltage between 8 – 24 volts and as such cannot shock you. The household currents, which are dangerous, are usually stepped down to low voltage by the bell transformer before use.

3. Can a doorbell transformer go bad?

Yes, it can, but not as often as you may think. When your bell stops working, many things could be responsible, it may be the chime, push-button and sometimes the transformer. So, be sure the fault is from your transformer before changing it.

Here is more information on how to test a doorbell transformer

Doorbell, not loud enough. What can I do?

There is nothing you can do than to replace the transformer if it is a wired doorbell, but for wireless doorbells, you can increase the volume and also upgrade the chime.

Best doorbell for the deaf

since the deaf cannot hear a ringing bell, special doorbells with loud and visual alerts are made for them.

The bell comes with bright flashing lights and an extra loud bell that will surely make the deaf notice the presence of the visitor.

My doorbell keeps ringing, why?

If your chime keeps ringing especially on a wired doorbell, know that the button stacked.

Or that the button wires joined. Lose the push button and correct the error.