Baby monitor

From ArticleWorld

A baby monitor is a radio transmitter that allows a parent or baby-sitter to listen to sounds or movements made by an infant from a distance. It consists of two parts: a transmitter and a receiver. The transmitter, which consists of a microphone, is kept beside the baby and the receiver, which has a speaker, is carried around by the carer.

Types

Baby monitors can be simplex (uni-directional) or duplex (bi-directional).

As the name suggests, simplex baby monitors work one way only and notify the carer when the baby moves or cries.

Duplex monitors are two-way and allow the carer to soothe the baby by talking, singing or playing music to him or her, and - if the child is old enough - to even have a conversation.

Technology

In the past, baby monitors did not use radio; they instead had a cable connecting the receiver to the transmitter.

Many baby monitors have light indicators, which can be useful for deaf persons or places where the playing of sound may not be acceptable. Newer models feature digital cameras enabling the carer to see the baby's actions. Some devices are able to detect movements, and others can have vibrating alerts.

The receiver is usually powered by a battery as it has to be carried about by the carer, although some require to be plugged in and hence cannot be carried about. The transmitter, which is stationary, is usually plugged into the wall. Baby monitors can come with single or multiple receivers.

High-end models offer high frequencies up to 900 MHz and hence better quality reception. However, these have the drawback of interference with other baby monitors and the possibility of eavesdropping. Lower bandwidth models between 40 and 50 megahertz have shorter ranges but are good enough for average use and are recommended for those living in cities.